Bhuj2011-abstractvolume

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International Symposium on

“The 2001 Bhuj Earthquake and Advances in Earthquake Science (AES 2011)”

(22-27 January 2011)

LOCAL ORGANIZING COMMITTEE: Chairman : Ravi Saxena,Add. Chief Secretary, DST, Government of Gujarat Secretary : B.K. Rastogi, Director General, ISR, Gandhinagar Members : T.P. Singh, Director, BISAG A.M. Prabhakar, Director, Gujcost, Ahmedabad Dilip Gadhvi, Executive Director, Science City, Ahmedabad Jwalant Trivedi, Deputy Secretary, DST, Government of Gujarat

NATIONAL ADVISORY COMMITTEE: Harsh K.Gupta, Panikkar Professor, NGRI, Hyderabad

Sudhir Jain, Director, Indian Institute of Technology, Gandhinagar

V. P. Dimri, Distinguished Scientist, NGRI, Hyderabad B. Bhattacharjee, Member, National Disaster Management Authority, New Delh

J. R. Kayal, CSIR Emeritus Scientist, Jadavpur University, Kolkata

B. R. Arora, Former Director, Wadia Institute of Himalayan Geology, Dehradun

A.K. Singhvi, Outstanding Scientist & Dean, PRL, Ahmedabad

Ajit Tyagi, Director General, India Meteorological Department, New Delhi

B. K. Bansal, Advisor and Head (Seismology), Ministry of Earth Science, New Delhi R. K. Chadha, Scientist, National Geophysical Research Institute, Hyderabad

O.P. Mishra, Geophysicist, Geological Survey of India, Kolkata

INTERNATIONAL ADVISORY COMMITTEE: Alik Ismail-Zadeh, Secretary General, IUGG Wu Zhongliang, President, IASPEI Roger Bilham, Colorado University, USA Mark Petersen, Head Federal Earthquake Hazard Mitigation Program. USGS, Colorado

Satish Singh, Instituite de Physique de Globe de Paris, France Ramesh P Singh, Vice-President, IUGG Georisk Commission

T. Yokoi, Senior Research Scientist, IISEE, BRI, Japan Arantza Ugalde, Geological Survey of Cataluniya, Spain

Amod Mani Dixit, President, National Centre for Disaster Management, Nepal

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AES-2011 PROGRAM

21st January, 2011 Time Program 15:00 – 18:00 Registration 18:30 – 19:30 Light & Sound show at Akshar Dham 20:00 – 21:00 Icebreaker

22nd January, 2011 08:00 – 10:00 Registration 10:00 – 11:00 Inauguration 1:00 – 12:00 High Tea Time Session Subject Place 12:00 – 13:00 ISES Lecture & Special Lecture 1 Auditorium 13:00 – 14:00 Lunch 14:00-16:00 Special Lectures(2,3,4,5,6,7) Auditorium

16:00-18:00 S1-8 Papers Bhuj Earthquake and Aftershock Studies

Conference Room No-2

15:00-18:30 S16-14 Papers IGCP Session on Archeoseismology


16:00-18:30 Poster session in Display Area 19:00 – 21:00 Gala Dinner

23rd January, 2011 08:00 – 8 :30 Registration 08:30 – 09:30 Special Lectures(8,9) Auditorium 09:30 – 10:30 S4-6 Papers Paleoseismology and

Historical Seismology Conference Room No-1

10:30 – 11:00 Tea 11:00 – 13:00 S14-7 Papers Ground Response Studies for

Nuclear Power Plants Auditorium

S12-7 Papers Remote Sensing, GPS & InSAR


S4-6 Papers(continued) Paleoseismology and Historical Seismology


13:00 – 14:00 Lunch 14:00 – 17:00 S3-12 Papers Seismicity and Earthquake

Source Processes Auditorium

S9-17 Papers Seismic Hazard Assessment / Microzonation


S2-11 Papers Intraplate Seismicity Conference Room No-2 17:00 –17:30 Tea/Snacks 17:30 –18:30 Special Lecture 10 Auditorium 18:30 –19:30 Poster session in Display area 20:00 – 21:00 Dinner

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24th January, 2011 Time Session Subject Place

08:30 – 10:30 S11-7 Papers Earth’s Interior, Structure & Dynamics

Auditorium

S5-18 Papers Earthquake Precursors and Prediction Studies


S8-8 Papers Earthquake Ground Motion and Damaging Earthquakes


10:30 – 11:00 Tea 11:00 – 13:00 S7-9 Papers Real Time Seismology, Early

Warning & Loss Assessment Auditorium

S5-18 Papers(continued) Earthquake Precursors and Prediction Studies


S15-4 Papers Tsunami Modeling Conference Room No-2 13:00 – 14:00 Lunch 14:00 – 15:00 Special Lectures (11, 12, 13) Auditorium 15:00 – 17:00 S6-6 Papers Seismic Wave Propagation,

Amplification and Basin Effect

Auditorium

S10-7 Papers Tectonics and Crustal Movements


S13-4 Papers Exploration for Oil and Crustal Structure


17:00 – 17:30 Tea 17:30 – 18:30 Concluding Session 20:00 – 21:00 Dinner

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Special Lectures Page No.

ISES Lecture

Program on study of earthquake precursors in India Harsh Gupta, Panikkar Professor National Geophysical Research Institute,Hyderabad

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Special-1

Shailesh Nayak Secretary, Ministry of Earth Sciences, New Delhi

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Special-2 India’s tsunami warning system: A success story Harsh Gupta, Panikkar Professor, National Geophysical Research Institute,Hyderabad

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Special-3 Time-varying Tsunami Characteristics in Wavelet Domain V.P.Dimri, Distiguished Scientist, NGRI, Hydrabad

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Special-4 Making of probabilistic seismic hazard map of India for the Bureau of Indian Standards B.K. Rastogi, Director General Institute of Seismological Research, Gandhinagar

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Special-5 New probabilistic seismic hazard map of India R.N.Iyengar Center of Disaster Mitigation,Jain University, Baglaore-Kanakapura Road, Jakkasandra

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Special-6 Recommendations for earthquake safety and retrofitting in Gujarat Padmashree Dr. Anand S. Arya (FNA, FNAE; Ex-National Seismic Advisor MHA, GoI-UNDP Professor Emeritus of Earthquake Engineering, IIT- Roorkee

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Special-7 Nuclear power program of India and seismic safety of Nuclear Power Plants S K Jain CMD, NPCIL, Mumbai

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Special-8 Structure, tectonics & active faults of Kutch rift basin, Gujarat, Western India S. K. Biswas Formerly: Director, KD Malviya Institute Petroleum Exploration,ONGC, Dehradun

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Special-9 A testable model for intraplate earthquakes Pradeep Talwani(Retired) Dept. of Earth and Ocean Sciences, University of South Carolina, Columbia,USA

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Special-10 Space inputs in disaster monitoring, mitigation and early warning. R.R.Navalgund Director, Space Application Center,ISRO,Ahmedabad

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Special-11 Bhuj 2001 earthquake – revisiting existing knowledge of structural behavior of traditional and new constructions, geological hazards of the Kutch region and the regime of seismic safety Alpa Sheth, Seismic Advisor,GSDMA,Gandhinagar

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Special-12 The road to seismic safety Sudhir Jain Director, IIT Gandhinagar.

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Special-13 Bhuj earthquake and role of CEPT University in post disaster scenario V. R. Shah (H.O.D Structural Design department, CEPT University, Ahmedabad

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LIST OF PAPERS Kn: Keynote (20 min), I: Invited (15 min), C: Contributed (15min), P: Poster

Page No.

S1: Bhuj Earthquake and Aftershock Studies 1

Session Chairman: Mark Petersen Co-Chairman: Prabhas Pande

Session Date: 22nd January, 2011 Session Time: 16:00 – 18:00

S1_Kn1 Geoseismological investigation of 26 January 2001 Bhuj earthquake Prabhas Pande Geological Survey of India

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S1_Kn2 Delineation of crustal and lithospheric structures below the Kachchh…….. Prantik Mandal National Geophysical Research Institute (CSIR), Hyderabad, India

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S1_Kn3 Seismic source of the 2001 Bhuj earthquake….. J R Kayal Indian School of Mines, Dhanbad.

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S1_I1 Impact of the 2001 M 7.7 Bhuj earthquake on hazard estimates in the US.. Mark Petersen U.S. Geological Survey, Golden, CO, USA

3

S1_I2 Targeting the future great earthquakes : Global monitoring and the 26 January 2001 Bhuj, India case Vladimir G. Kossobokov et al. International Institute of Earthquake Prediction Theory and Mathematical Geophysics,

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S1_I3 Relocation of aftershocks of the 2001 Bhuj earthquake…. Jim Mori et al Disaster Prevention Research Institute, Kyoto University, Japan.

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S1_C1 Probabilistic assessment of earthquake hazards using method of moments in the Kutch Jayant N. Tripathi Department of Earth and Planetary Sciences, University of Allahabad

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S1_C2 Detection complex networks of Bhuj earthquake (2001) and aftershocks…. MostafaAllameh-Zadeh Seismology Department, IIEES

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S1_P1* Ground deformation and liquefaction structures formed due to 2001 Kachchh earthquake R.D. Shah et al. M.G. Science Institute, Navrangpura, Ahmedabad

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S1_P2* Seismicity monitoring of Bhuj aftershocks Santosh Kumar et al. Institute of Seismological Research, Gandhinagar

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S2:Intraplate Seismicity 7

Session Chairman: O. P. Mishra Co-Chairman:Bijendra Singh

Session Date: 23rd January, 2011 Session Time: 14:00 – 17:00

S2_Kn1

Seismotectonics of Bhuj earthquake of 2001 based on gravity and magnetic signatures….. D. C. Mishra National Geophysical Research Institute (CSIR), Hyderabad

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S2_I1 Geodynamics of the Kachchh Basin: Gravity- Magnetic Perspective D.V. Chandrasekhar and B. Singh National Geophysical Research Institute (CSIR), Hyderabad 500 007)

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S2_C1

Geodetic crustal strain patterns over the Satpura mountain belt…. S. Mohanty Department of Applied Geology, Indian School of Mines, Dhanbad , India

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S2_C2

Mafic crust and earthquake activity in the high velocity Indian shield. O.P. Pandey National Geophysical Research Institute,Uppal Road, Hyderabad

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S2_C3

An intraplate earthquake and the study of ground response analysis….. H.S.Mandal Earthquake Risk Evaluation Centre, India Meteorological Department, New Delhi

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S2_C4

Study of the shallow seismic activity of offshore southern and eastern Sri Lanka Shantha S.N. Gamage and S.A.D.L.K. Suraweera Department of Physics, University of Sri Jayewardenepura, Sri Lanka

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S2_C5 Assessing the intraplate origin for subduction zone mega-thrust earthquake… Prosanta K. Khan Department of Applied Geophysics, Indian School of Mines, Dhanbad

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S2_C6 Crustal strain pattern over a part of southern India and its implication for seismotectonics ArijitBarik and S. Mohanty Department of Applied Geology, Indian School of Mines, Dhanbad , India

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S2_C7 Intermittent micro-seismic activity in the vicinity of Nanded city of west central India Md. Babar Shaikh,Maharashtra

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S2_C8 Structural controls on the intraplate seismicity of the Kachchh region, India. SushmitaSinha and S. Mohanty Department of Applied Geology, Indian School of Mines, Dhanbad, India

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S2_C9 Improved Seismicity Trends in the Koyna-Warna Region through Earthquake Relocation using hypoDD. G. Srijayanthi et al. National Geophysical Research Institute, Hyderabad

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S2_P1* Unusually large number of earthquake sequences in Saurashtra since 2006……. B.K. Rastogi et al. Institute of Seismological Research, Gandhinagar

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S2_P2* Spatiotemporal complexity of intraplate seismicity: a reverie and its multifarious… ArjunTiwari Applied Geophysics, Indian School of Mines Dhanbad

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S2_P3*

New insight into crustal heterogeneity beneath the 2001 Bhuj earthquake … A. P. Singh et al. Institute of Seismological Research (ISR), Raisan, Gandhinagar, Gujarat

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S3: Seismicity and Earthquake Source Processes 16

Session Chairman: J R Kayal Co-Chairman: Prantik Mandal


S3_I1 Seismic hazard assessment for Karachi, Pakistan MonaLisa and 2M.Qasim Jan Department of Earth Sciences, Quaid-i-Azam University, Islamabad, Pakistan.

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S3_I2 An overview of the seismic activity and associated hazards in South-America …. Omar J. Pérez, Carlos Rodríguezand José L. Alonso Simon Bolivar University, Dpt. Earth Sciences, Caracas, Venezuela

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S3_C1 A study of source parameters, site amplification functions and attenuation parameter Manisha, Dinesh Kumar and S.S. Teotia Department of Geophysics, Kurukshetra University Kurukshetra, India

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S3_C2 Source parameters and scaling relations for small earthquakes in Kumaon Himalaya K. Sivaram et al. National Geophysical Research Institute, Hyderabad India

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S3_C3 Apatial statistics: a technique to constrain earthquake cluster….. Basab Mukhopadhyay Geological Survey of India

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S3_C4 Estimation of seismic source parameters in northeast (NE) India from body wave spectra Alok Kumar Mohapatra and William Kumar Mohanty Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur

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S3_C5 Analysis of the seismic activity of el asnam region F.Bellalem et al. Seismological Dept .Survey.CRAAG.BP 63 Bouzareah.16340 Algiers-Algeria

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S3_C6 Stress pattern in the Kangra-Chamba region of Northwest Himalaya…. Dilip Kr Yadav et al.. Wadia Institute of Himalayan Geology, Dehradun-248001, India.

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S3_C7 Estimation of earthquake source parameters and site response….. Prantik Mandal and Utpal Dutta National Geophysical Research Institute (CSIR), Hyderabad, India

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S3_C8 Earthquake interevent time clustering inferred from mixed models. Talbi A. et al. Centre de Recherche en AstronomieAstrophysiqueetGéophysique, CRAAG, Algeria.

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S3_C9 Triggering is fine but what causes earthquakes in Koyna-Warna region? V.K. Gahalaut and Kalpna Gahalaut National Geophysical Research Institute, Uppal Road, Hyderabad

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S3_C10 Source characteristics of Delhi earthquake (ML:4.3) of 25th Nov., 2007 Rajesh Prakash, A. K. Shukla and R. K. Singh India Meteorological Department, New Delhi

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S3_P1* Waveform inversion of local earthquakes using broadband data of Koyna…. D. Shashidhar et al. National Geophysical Research Institute, Uppal Road, Hyderabad

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S3_P2* Remotely triggered seismicity due to the 2001 Bhuj earthquake G. Surve and G. Mohan Dr. K. S. Krishnan Geomagnetic Research Laboratory (I.I.G), Leelapur Road, Chamanganj, Allahabad

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S3_P3* Evidence for transverse tectonics in Sikkim Himalaya from seismicity…. Pinki Hazarika et al. National Geophysical Research Institute, Uppal Road, Hyderabad

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S3_P4* Evidence for right lateral strike slip environment in Kutch rift…... Ch. Nagabhushana Rao et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat 382018, India.

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S4 : Paleoseismology and Historical Seismology 26

Session Chairman: V C Thakur Co-Chairman: Javed Malik

Session Date: 23rd January, 2011 Session Time: 09:30 – 10:30 & 11:00-13:00

S4_Kn1 Luminescence dating in paleoseismology and neotectonics: an overview A.K. Singhvi et al. Physical Research Laboratory, Ahmedabad , India

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S4_I1 Active faults in Kachchh region and issue on the seismic hazard assessment M. Morino et al. OYO International Corporation;

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S4_C1 Partitioning of convergence in Northwest sub Himalaya…... V.C. Thakur et al. Wadia Institute of Himalayan Geology, Dehradun-248001, India.

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S4_C2 Paleoseismic investigations in the Kopili Lineament Zone, Northeast India. Devender Kumar et al. National Geophysical Research Institute, Uppal Road, Hyderabad

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S4_C3 Paleoseismology along an intraplate fault: Talas-Fergana, Tien-Shan mountains, central Asia. Derek Rust et al. School of Earth and Environmental Sciences, University of Portsmouth, UK.

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S4_C4 Active fault mapping using high resolution geophysical field investigation in Kachchh… A. K. Gupta et al. Institute of Seismological Research, Gandhinagar , Gujarat, India

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S4_P1* Morphotectonic control on drainage network evolution in the Upper Narmada Valley… Girish Ch. Kothyari and B. K. Rastogi Institute of Seismological Research, Raisan, Gandhinagar, Gujarat India

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S5: Earthquake Precursors and Prediction Studies 30

Session Chairman: B R Arora Co-Chairman: R K Chadha

Session Date: 24th January, 2011 Session Time: 08:30 – 10:30 &11:00-13:00

S5_I1 Changing Scenario of earthquake precursory research B. R. Arora Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun, India

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S5_I2 Monitoring well water level changes – what did we learn from our experiences in India R K Chadha National Geophysical Research Institute, Hyderabad-500007

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S5_C1 Soil-gas geochemistry for earthquake monitoring and fault studies in Taiwan. Vivek Walia et al. 1National Center for Research on Earthquake Engineering,Taiwan,

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S5_C2 Fractal correlation dimension analysis to identify precursory pattern prior to 15th July 2009… S.K. Mondal, R. Meena and and P. N. S. Roy Department of Applied Geophysics, Indian School of Mines, Dhanbad-826004, Jharkhand,

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S5_C3 Investigations of anomalous signals prior to large earthquakes……. WenBin Shen et al. Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, Chin

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S5_C4 Changes observed prior and after the Gujarat earthquake of 26 January.. Ramesh P. Singh and Waseem Mehdi School of Earth and Environmental Sciences,Chapman University,USA

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S5_C5 Application of acoustic sounding in earthquake precursor detection lessons from Bhuj…. H.N. Dutta and B.S. Gera Roorkee Engineering & Management Technology Institute, Shamli.

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S5_C6 Anomalous changes in groundwater and soil-gas radon concentrations….. R.C. Ramola and Sushil Kumar Wadia Institute of Himalaya Geology, Dehra ,India

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S5_C7 Anomalous variations of foF2 during Bhuj earthquake of 26 January, 2001 …… O.P. Singh et al. Department of Physics, Faculty of Engineering & Technology, R.B.S. College,

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S5_C8 Signature of seismo-electromagnetic signals (ses) in prediction of earthquakes Vinod Kumar Kushwah Department of Physics, Hindustan College of Science & Technology, Farah, Mathura

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S5_C9 Precursory Earthquake Studies in Maharashtra, especially in Koyna Region Arun Bapat¹ and M.A.Ghatpande2 11/11, Tara Residency, 20/2, Kothrud, Pune- 411038, 2 Formerly from MERI, Nashik

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S5_C10 Earthquake pre-cursory studies in Koyna-Warna region, India: some vital observations D.V. Reddy and P. Nagabhushanam National Geophysical Research Institute ,Hyderabad

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S5_C11 Detection of possible precursors of the 2010 Chile earthquake using ….. Jun Yi et al. Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, China

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S5_C12 Seismic Acoustic Emission (SAE) as an earthquake precursor G. Suresh and R. S. Dattatrayam India Meteorological Department, , New Delhi

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S5_C13 Study of multi-parameter gas-geochemical precursor signals of a distant earthquake….. H. Chaudhuri et al. Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata , India.

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S5_C14 Predictability of valsad earthquake swarms Gujarat, India H.N.Srivastava, Formerly in India Meteorological Department Gujarat Engineering Research Institute,Vadodara

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S5_C15 The analysis of microseisms before the 2008 great Wenchuan earthquake. Xiao-GuangHao, Xiao-Gang Hu. Institute of Geodesy and Geophysics, ChineseAcademy of Sciences, China.

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S5_C16 Multi-parametric geophysical observations at Ghuttu, Garhwal Himalaya: Radon component V.M.Choubey Wadia Institute of Himalayan Geology

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S5_P1* Thermal and ionospheric anomalies associated with the Haiti earthquake of January 12, 2010 Suryanshu Choudhary, Shivalika Sarkar and A.K.Gwal Space Science Laboratory, Department of Physics

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S5_P2* Earthquakes in UttranchalHimalaya, India Arun K Shandilya & AnuragShandilya Department of Applied Geology, Dr. Hari Singh Gour University, Sagar (M.P.) India

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S5_P3* Low field magnetic measurements: a modern tool for prediction of earthquake Dr Rajeev Vaghmare GRIIC, GERMI Gandhinagar.

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S5_P4* Foreshock clustering as precursory pattern for the Kachchh earthquakes in Gujarat, India Sandeep Kumar Aggarwal et al Institute of Seismological Research, Village Raisan, Gandhinagar- 382007

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S5_P5* Status of superconducting gravimeter and MPGO network of Kachchh Arun Gupta, RashmiPradhan, M.S.B.S. Prasad and B.K.Rastogi Institute of Seismological Research, Raisan, Gandhinagar, Gujarat

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S6 : Seismic Wave propagation, Amplification and Basin Effect 47

Session Chairman: Praveen Malhotra Co-Chairman: MostafaAllameh-Zadeh

Session Date: 24th January, 2011 Session Time: 15:00 – 17:00

S6_C1 A possibility of site effects due to the past earthquakes at Anjar, Gujarat state, India. Fumio Kaneko et al. Oyo internation Corporation

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S6_C2 Determination of Site amplification in the Northern Iran from Inversion of Strong-Motion… B. Hassani, H. Zafarani International Institute of Earthquake Engineering and Seismology, Iran.

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S6_C3 Estimation of dynamic properties of Lucknow soil T.G. Sitharam, S. M .Patil. Professor, Department of Civil Engineering, Indian Institute of Science, Bangalore, India

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S6_C4 Liquefaction susceptibility of lucknow soil T.G. Sitharam et al. Professor, Department of Civil Engineering, Indian Institute of Science, Bangalore, India.

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S6_C5 Site characterization: which dataset to use? Manish Shrikhande and SusantaBasu Department of Earthquake Engineering, Indian Institute of Technology Roorkee

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S6_C6 The ground effect of the Skopje 1963 earthquake……. Apostol Poceski, R.Macedia Fac. of Civil Eng.Univ.Sent Cyril &Metodi, Skopje

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S6_P1* Attenuation of coda waves of local earthquakes in the Northeastern India Alok Kumar Mohapatra, William Kumar Mohanty Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur

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S6_P2* Spectral decay parameter (?) using the accelerograms of the earthquakes in Himalaya Renu Yadav, Kavita Rani, Gunjan Dhiman and Deepak Kumar Department of Geophysics, Kurukshetra University Kurukshetra,India

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S6_P3* Estimation of coda-Q using a non-linear (Gauss-Newton) regression Savita Singh, Sumedha, Monika Wadhawan and Vandana Department of Geophysics, Kurukshetra University Kurukshetra, India

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S7 : Real Time Seismology, Loss Reduction and Early Warning 52

Session Chairman: R.S.Dattatrayam Co-Chairman: E. Hohnecker


S7_Kn1 Current trends in seismic instrumentation and earthquake monitoring in India R.S.Dattatrayam et al. India Meteorological Department, Ministry of Earth Sciences, Lodi Road, New Delhi

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S7_I1 EDIM – earthquake disaster information system for the Marmara region, Turkey Wenzel F et al. Geophysical Institute, Karlsruher Institute of Technology (KIT),

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S7_C1 Seismic loss reduction/estimation technique for use in educational spaces Chandra Bhakuni QuakeSchool Consulting Pvt. Ltd., Navrangpura, Ahmedabad, Gujarat, India

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S7_C2 The seismic alert system of Mexico (SASMEX). Espinosa-Aranda J. M et al. Centro de Instrumentación y RegistroSímico, A. C., Mexico.

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S7_C3 Early warning system for transportation lines E. Hohnecker et al. Department of Railway Systems, Karlsruhe Institute of Technology, Germany.

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S7_C4 Seismo-tectonic interpretations for the Delhi region based on the data recorded at Delhi… VivekMahadev and NeeluMathur Delhi Seismic Unit, Seismology Division, BARC, New Delhi

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S7_C5 Earthquake vulnerability assessment of Gujarat port sites viz-a-viz seismic disturbances Terala Srikanth et al. Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad, India.

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S7_C6 Performance analysis of mundra panipat pipeline crossing Kachhach mainland fault… Vasudeo Govind Choudhary and Ramancharla Pradeep Kumar Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad, India.

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S7_C7 Rapid visual survey of existing buildings in Gandhidham and Adipur cities, Kachchh, Gujarat Terala Srikanth et al. Earthquake Engineering Research Centre, IIIT Hyderabad, Gachibowli, Hyderabad, India.

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S8 : Earthquake Ground Motion and Damaging Earthquakes 58

Session Chairman: Kojiro Irikura Co-Chairman: Sumer Chopra


S8_I1 The great Sumatra earthquakes: Results from recent marine studies Satish C. Singh. Institut de Physique du Globe de Paris, France and University of Cambridge, UK

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S8_C1 Estimation of H/V ratio in different sites in northern Algeria with aftershock sequences…. M.Mobarki et al. Seismological Dept ,Algeria

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S8_C2 Ground motion parameters of Shillong plateau: One of the most seismically active zones…... SaurabhBaruah et al. Geoscience Division, North-East Institute of Science and Technology (CSIR), Assam, India

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S8_C3 Characterization of seismic regime in NW Himalaya: Persistent and high seismicity in……. Naresh Kumar et al. Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun, India

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S8_C4 Strong ground motion simulation of the 2001/01/26 Bhuj, India earthquake Tao-Ming Chang National Center for Earthquake Engineering Research, Taipei, Taiwan

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S8_C5 Recipe for predicting strong ground motions for inland mega fault earthquakes Kojiro IRIKURA and Susumu KRAHASHI Aichi Institute of Technology & Kyoto University, Toyota, Aichi, Japan

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S8_C6 Estimation of damage to various types of buildings in Gujarat from a future large earthquake Sumer Chopra, Dinesh Kumar and B.K.Rastogi Institute of Seismological Research, Gandhinagar

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S8_C7 Strong motion simulation of great earthquake in the central seismic gap… Kapil Mohan and A. Joshi Institute of Seismological Research, Gandhinagar, Gujarat(India)

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S8_P1* Attenuation relations for the Kumaon and Garhwal Himalaya, Uttarakhand, India… A.Joshi et al. Department of Earth Science, Indian Institute of Technology Roorkee, Roorkee, India.

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S8_P2* Prediction of strong ground motion in the coastal and economically important regions…... Kapil Mohan Institute of Seismological Research, Gandhinagar, Gujarat (India)

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S9: Seismic Hazard Assessment / Microzonation 64

Session Chairman: A. Peresan Co-Chairman 1: T G Sitharam Co-Chairman 2: Imtiyaz Parvez


S9_I1 Seismic hazard assessment for Gandhidham; Kutch; Gujarat Fumio Kaneko et al. OYO International Corporation

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S9_I2 Seismic hazard assessment based on unified scaling law for earthquakes Anastasia K. Nekrasova and Vladimir G. Kossobokov International Institute of Earthquake Prediction Theory and Mathematical Geophysics

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S9_I3 Neo-deterministic seismic hazard techniques – contributions to the alternative……. Kouteva M et al. NIGGG-BAS, Sofia, Bulgaria

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S9_I4 Neo-deterministic seismic hazard and pattern recognition techniques… Peresan et al. Department of Earth Sciences, University of Trieste,Triest.,

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S9_I5 Ground motion at bedrock level in Delhi city from different earthquake scenarios Imtiyaz A Parvez et al. (CMMACS), NAL Belur Campus, Bangalore, India

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S9_I6 Probabilistic seismic hazard macrozonation of India Prof. T.G. Sitharam, Mr.SreevalsaKolathayar and Dr. K.S. Vipin Department of Civil Engineering, Indian Institute of Science, Bangalore

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S9_I7 Study of the local site effects on seismic hazard using deterministic and probabilistic approaches: A case…. Prof. T.G. Sitharam, Mr. Naveen James, and Dr. K.S Vipin Department of Civil Engineering, Indian Institute of Science

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S9_C1 Seismic hazard deaggregation in terms of magnitude, distance and azimuth …… M. Hamdache et al. Departement Étudeset Surveillance Sismique, CRAAG, Algiers.

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S9_C2 Determination site effect of Zarqa City-Jordan based on microtremors field measurements: A microzonation study Waleed Eid Olimat Natural Resources Authority (NRA), Jordan Seismological Observatory (JSO),Jordan.

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S9_C3 Probabilistic seismic hazard analysis for mitigating societal risk from earthquakes Dr. Praveen K. Malhotra, P.E. StrongMotions Inc., Sharon, MA, USA

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S9_C4 Influence of source and epicentral distance on local seismic response in Kolkata city, India. William K. Mohanty et al. Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur

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S9_C5 Neo-deterministic and probabilistic seismic hazard assessments…… E. Zuccolo et al. European Centre for Training and Research in Earthquake Engineering,Italy.

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S9_C6 Evaluation of site classification for soils in Lucknow urban centre …………… Abhishek Kumar et al. Department of Civil Engineering, Indian Institute of Science, Bangalore,India.

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S9_C7 Site response studies in the Andaman and Nicobar islands K Sushini et al. National Geophysical Research Institute ,Uppal Road, Hyderabad

72

S9_C8 Analysis of embedded pipeline induced by earthquake excitation under…. Goktepe F et al. Department of Civil Engineering, Sakarya University, Sakarya, Turkey

72

S9_C9 Seismic hazard assessment of Gujarat. K. S. Vipin et al. Department of Civil Engineering, Indian Institute of Science (IISc), Bangalore

72

S9_C10 Earthquake hazard assessment for public safety Lalliana Mualchin Retired Chief Seismologist, Office of Earthquake Engineering, California Dept. of Transportion, Sacramento, California and Seismic Consultant to the Govt. of Mizoram, India, Disaster Mangement & Rehabilitation Dept., Govt. of Mizoram, Aizawl)

73

S9_P1* Geo-informatics based conceptualization of earthquake disaster management system Ajeet P. Pandey, R.K. Singh and A.K. Shukla Earthquake Risk Evaluation Center, India Meteorological Department, New Delhi

74

S9_P2* Probability of occurrence of largest earthquakes in Jharkhand and nearby region….. AkashAdwani et al. Dept. of Applied Geophysics, Indian School of Mines, Dhanbad (India).

74

S9_P3* Preliminary site characterization through integration of geophysical and geotechnical data at GIFT … B.K. Rastogi et al. Institute of Seismological Research (ISR), Raisan, Gandhinagar, Gujarat, India

75

S9_P4* Preliminary site characterization through integration of geophysical and geotechnical data at Dholera …. B.K. Rastogi et al. Institute of Seismological Research (ISR), Raisan, Gandhinagar, Gujarat, India

76

S9_P5* Estimation of liquefaction potential of Dholera region based on SPT N-values Sarda Maibam et al. Institute of Seismological Research, Raisan Village, Gandhinagar

76

S9_P6* Vs30 and site amplification studies in Dholera SIR Region, Gujarat, India B. Sairam et al. Institute of Seismological Research, Raisan, Gandhinagar

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S10 : Tectonics and Crustal Movements 78

Session Chairman: H N Srivastava Co-Chairman: Y S Kim


S10_I1 Seismotectonics and velocity structure of the Kumaon - Garhwal Himalaya P. Mahesh et al. National Geophysical Research Institute (CSIR), Hyderabad, India

78

S10_I2 New evidence of the involvement of the low density fluid phase in the deep crust seismicity M.V.Rodkin International Institute of Earthquake Prediction Theory and Mathematical Geophysics,Russia,

79

S10_I3 Crustal configuration and seismo-tectonics of the Kutch rift basin from analysis … Mita Rajaram and S.P.Anand Indian Institute of Geomagnetism, NewPanvel(W), Navi Mumbai.

79

S10_C1 Seismotectonic studies of kachchh basin using gravity surveys after 2001 Bhuj earthquake Rashmi Pradhan et al. Institute of Seismological Research, Gandhinagar

80

S10_C2 About the geophysical studies are being carryout by WIHG in the NW Himalaya. Sushil Kumar Wadia Institute of Himalaya Geology, Dehra Dun, India

80

S10_C3 Fractal dimension and b-value mapping in NW Himalaya and adjoining regions. Sushil Kumar Wadia Institute of Himalaya Geology, Dehra Dun, India

81

S10_C4 Stress pulse migration by viscoelastic process for long - distance delayed triggering of ….. B.K. Rastogi Institute of Seismological Research, Gandhinagar, India

81

S10_P1* Active deformation and lithotectonic model of Saurashtra Horst, Gujarat, India Girish Ch. Kothyari et al. Institute of Seismological Research, Gandhinagar , Gujarat, India

82

S11 : Earth’s interior , structure & dynamics 83

Session Chairman: M.Ravi Kumar Co-Chairman:WenBin Shen


S11_C1 Spatial distribution of scatterers in the crust of Kachchh region, Western India by inversion analysis of coda… B. Sharma et al. Institute of Seismological Research, Raisan, Gandhinagar, India

83

S11_C2 Moho depth variation in the Shillong-Mikir hills plateau in North Eastern region of India…… SaurabhBaruah and Dipok K. Bora Geoscience Division, CSIR North-East Institute of Science and Technology

83

S11_C3 Seismic signatures of volcanism in the upper mantle beneath NW DVP G. Mohan Department of Earth Sciences, Indian Institute of Technology Bombay,Powai, Mumbai.

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S11_C4 Crustal structure and upper mantle deformation in eastern Himalayan syntaxis…… DevajitHazarika, B.R. Arora Wadia Institute of Himalayan Geology,Dehradun , India

85

S11_C5 The signal of transition-zone anisotropy in the normal mode coupling…. Xiao-gang HU, Xiao-guangHao Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics.

85

S11_C6 Surface wave tomography across the Indian shield, Indo-Gangetic plains and the Himalayan…. N. Purnachandra Rao et al. National Geophysical Research Institute, Uppal Road, Hyderabad

86

S11_C7 Anisotropy of the Indian crust from splitting of Ps phases from the Moho Narendra Kumar et al. NGRI, Hyderabad.

86

S11_P1* A comparative study on seismic wave attenuation characteristics of Koyna, Chamoli And Gujarat regions Babita Sharma et al. Institute of Seismological Research, Raisan, Gandhinagar, India.

87

S11_P2* Inversion of seismic intensity data for the determination of three-dimensional attenuation structures…. Babita Sharma et al. Institute of Seismological Research, Gandhinagar.

87

S11_P3* Seismic evidences for underplating and uplifted crust beneath the Northwestern deccan volcanic province…. K. Madhusudana Rao et al. Institute of Seismological Research, India.

88

S11_P4* Shear wave splitting beneath the northwestern deccan volcanic province…………... K. Madhusudana Rao et al. Institute of Seismological Research, India.

88

S11_P5* Evaluation of the crustal structure of the Indus Block up to Saurashtra using GA inversion … Vishwa Joshi et al. ISR, Gandhinagar.

89

S11_P6* Shield like lithosphere of the lower Indus basin evaluated from observations of surface wave dispersion. Mukesh Chauhan et al. Institute of Seismological Research, Raisan, Gandhinagar, India

89

S12: Remote Sensing, GPS & InSAR 91

Session Chairman: V.K.Gahalaut Co-Chairman: Mita Rajaram


S12_I1 Weak mantle lithosphere in Kachchh, India probed by GPS…... D. V. Chandrasekhar and Roland Bürgmann National Geophysical Research Institute (CSIR), Hyderabad, India

91

S12_C1 SAR Interferometry detects post-seismic ground deformations related with 2001 Bhuj earthquake. Arun K. Saraf Department of Earth Sciences,Indian Institute of Technology Roorkee, ROORKEE, INDIA

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S12_C2 Ten years of GPS observations after 2001 Bhuj earthquake… C.D. Reddy et al. Indian Institute of Geomagnetism, New Panvel, Navimumbai, India.

92

S12_C3 Studies on seismic behaviour and associated topographic changes in NE India based…. R. K. Sukhtankar et al. Department of Atmospheric and Space Sciences, Pune University, Pune

92

S12_C4 Crustal deformation mapping in Kachchh, India using InSAR and GPS: Initial results K. M. Sreejith et al. Geosciences Division, Marine,Space Applications Centre (ISRO), Ahmedabad

93

S12_C5

The Tehri Dam, Uttarakhand: crustal strain and implications in case of reservoir induced …. Swapnamita C. Vaideswaran and Ajay Paul Wadia Institute of Himalayan Geology, Dehradun

93

S12_C6 Satellite altimeter derived geoid / gravity and the lithospheric density anomaly … Rajesh S et al. Geophysics Group, WadiaInsitute of Himalayan Geology, Dehradun

94

S12_P1* Post-seismic deformation associated with the 2001 Bhuj earthquake Pallabee Choudhury et al. Institute of Seismological Research, Raisan, Gandhinagar

95

S13: Exploration for Oil and Crustal Structure 96

Session Chairman: S.K.Biswas Co-Chairman: Satish Singh


S13_I1 On-land Kutch basin and its basement configuration from seismic refraction studies….. B. Rajendra Prasad Emeritus Scientist, (National Geophysical Research Institute, Uppal Road, Hyderabad, India.)

96

S13_I2 Integration of geophysical data for exploration of hydrocarbons - GIS application T. Harinarayana et al. NGRI, Uppal Road, Hyderabad, India

96

S13_I3 Impact of tectonics, sedimentation process and evolving trap style in Andaman island etc.. Sadip k Roy, IIT,Bombay

97

S13_C1

Geophysical Investigations of the Gulf of Kachchh, Northwest India. D. Gopala Rao and N. Mahendar Geology Department, Osmania University, Hyderabad, India

98

S13_C2

2D-geoelectric subsurface structure in the surroundings of the epicenter zone of 2001……. Kapil Mohan et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat, India

99

S13_P1* Identification of shallow geological features in the Wagad area (Kachchh) using 2D electrical survey Kapil Mohan et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat (India)

99

S13_P2* 2D electrical imaging survey to identify the shallow subsurface layer in the Gujarat international…. Kapil Mohan et al. Institute of Seismological Research, Raisan, Gandhinagar, Gujarat (India)

100

S13_P3* Passive Seismic Imaging of Petroleum Reservoir Mr.Sunjay, Exploration Geophysics,BHU, Varanasi,India.

100

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S14: Ground Response Studies for Nuclear Power Plants 101

Session Chairman: A.G. Chhatre Co-Chairman: CVR Murty

Session Date: 23rd January, 2011 Session Time: 11:00-13:00

S14_I1 Near-field ground motion simulation for the 26th January 2001 Gujarat earthquake STG Raghukanth and B. Bhanu Teja Dept. of Civil Engineering, IIT Madras-600036

102

S14_I2 Displacement-based Design of Structures: a consistent framework of limiting-strain based design method C. V. R. Murty Department of Civil Engineering, Indian Institute of Technology Madras,Chennai

102

S14_I3 Seismic Design of Bridges for Displacement Loading Rupen Goswami Department of Civil Engineering,Indian Institute of Technology Madras

103

S14_I4 Earthquake Experience based performance of civil structures, piping systems, cable trays, ducting and mechanical, electrical, instrumentation & control equipment from industries in India Faisal Dastageer et. al NPCIL, Mumbai

103

S14_I5 Seismic Analysis of a typical Nuclear Power Plant structure Apurba Mondal et. al Nuclear Power Corporation of India Ltd., Mumbai, India

104

S14_C1 Design of distribution systems, viz., piping, cable trays and ducting. Faisal Dastageer et al. NPCIL, Mumbai

104

S14_C2 Earthquake ground motion generation for nuclear power plant. Faisal Dastageer et al. NPCIL, Mumbai

105

S14_P1* Estimation of spectral decay parameter kappa, seismic moment, stress drop, source dimension….. Santosh Kumar et al. Institute of Seismological Research, Gandhinagar

106

S14_P2* Seismotectonic study to characterize the seismic sources in Gulf of Khambhat and prediction of strong … Sandeep Kumar Aggarwal et al. Institute of Seismological Research, Gandhinagar.

106

S14_P3* Site characterization using Vs30 and site amplification in Gujarat, India B. Sairam et al. Institute of Seismological Research, Raisan,Gandhinagar

107

S15: Tsunami Modeling 108

Session Chairman: V.P.Dimri Co-Chairman: A. Buchmann


S15_C1 Hydrodynamic modelling of 2004 Indonesian and 1945 Macran Tsunamis. R. Rajaraman and S. Joseph Winston Indira Gandhi Centre for Atomic Research, Kalpakkam , Tamil Nadu, INDIA.

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S15_C2 Tsunami assessment of Indian nuclear coastal sites for Sumatra 2004 and Makran 1945 Tsunami events. R. K. Singh, P Sasidhar Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai , India.

108

S15_C3 Development of paleo-tsunami database and hazard assessment for Indian subcontinent… Akhilesh K. Verma and William K. Mohanty Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, India.

110

S15_C4 Tsunami effect On Porbandar, Western Gujarat coast V. M. Patel et al. Ganpat University, GanpatVidyanagar, Mehsana-384002, Gujarat, India.

110

S15_P1* Numerical modeling of Arabian Sea tsunami propagation and its effect on the Gujarat……… A. P. Singh and B. K. Rastogi Institute of seismological research (ISR), Raisan, Gandhinagar, Gujarat (India)

111

S16: IGCP Session on Archeoseismology 112

Session Chairman: Javed Malik Co-Chairman: M Kazmer

Session Date: 22nd January, 2011&23rd January, 2011 Session Time: 14:00 – 17:00 &9:30-10:30

S16_Kn1 Archaeoseismology and the role of tectonics in the demise of the Indus Valley Civilization PradeepTalwani, Dept. of Earth and Ocean Sciences, University of South Carolina, Columbia, SC, USA.

112

S16_I1 Major Earthquake Occurrences in Archaeological Strata of Harappan Settlement at Dholavira (Kachchh, Gujarat) Ravindra Singh Bisht Former Joint Director General, Archaeological Survey of India, Ghaziabad

112

S16_C1 Archaeological evidences for a 12th -14th century earthquake at Ahichhatra, Barreilly (U.P.), India Bhuvan Vikrama et al. Archaeologist, Archaeological Survey of India, Agra.

113

S16_C2 Active fault influence on the evolution of landscape and drainage……. Javed N. Malik Department of Civil Engineering, Indian Institute of Technology Kanpur,Uttar Pradesh, India.

114

S16_C3 Signatures of active faulting in Southern peninsular India. Biju John et al. National Institute of Rock Mechanics, Kolar Gold Fields, India

114

S16_C4 Macroseismic intensity assessment of 1885 AD historical earthquake of NW Kashmir Himalaya.. Bashir Ahmad et al. Department of Education, J&K, Srinagar, India

115

S16_C5 Fault segmentation and propagation characteristics based on rupture patterns Jin-Hyuck Choi et al. GSGR, Dept. of Earth Environmental Sciences, Pukyong National University, Busan , Korea

115

S16_C6 Preliminary study on active faults around Mandi region, NW Himalaya, India Javed N. Malik and Santiswarup Sahoo Department of Civil Engineering, Indian Institute of Technology, Kanpur, India.

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S16_C7 Archaeology of earthquakes at Mahasthanghar (Province of Bogra, Bangladesh) Bruno Helly et al. Directeur de recherche au CNRS (émérite), Maison de

116

S16_C8 Archeoseismology of the A.D. 1545 earthquake in Chiang Mai, northern Thailand. Miklos Kazmer and Kamol Sanittham Department of Palaeontology, Eotvos University, Hungary

117

S16_C9 Paleoseismological analysis in north of Dushanbeh, Tajikistan (June 2010) H. Nazari et al. Geological survey of Iran, Seismotectonic group, Tehran, Iran

118

S16_C10 Archaeo seismological approach based on stone heritages in Gyeongju, SE Korea. M. Lee and Y.-S. Kim Dept. of Geosciences, Pukyong National University, Busan, Korea.

119

S16_C11

Discover and the characteristic initially search of Gaixiaruins's nature distortion Vestige, Guzhen County et al. Seismological Administration of Anhui Province,Hefei,Anhui P.R.China

119

S16_C12

Paleo-earthquake evidence from archaeological site in mesoseismal zone of 1819 Allah Bund event, Great Rann of Kachchh, Gujarat, Western India Malik J N et al. Department of Civil Engineering, Indian Institute of Technology Kanpur

120

Miscellaneous 121

M_P1*

Specific yield-water level fluctuation method an effective tool for quantitative evaluation of groundwater resource – a case study Syed Zaheer Hasan and M. Yusuf Farooqui GERMI, Gandhinagar and GSPC Gandhinagar

121

M_P2*

Environmental studies using Electrical Resistivity Method Sunita Devi & Rupal Malik Institute of Seismological Research, Gandhinagar

121

* Poster sessions have been scheduled at 17:00 hrs on 21st January and at 18:30 hrs on 22nd January.

122 - 24 January, 2011

The 2001 Bhuj Earthquake and Advances in Earthquake Science (AES-2011)

S1_Keynote-1

Geoseismological Investigation of 26 January2001 Bhuj Earthquake

Prabhas Pande (Geological Survey of India, JNRoad, Kolkata, E-mail: [email protected])

Of the intraplate seismic events, the 26 January 2001Bhuj earthquake will be remembered as one of thedeadliest, in which 13,805 human lives were lost, 1.77lakh injured and a total of 1,205,198 houses fully orpartly damaged in 16 districts of Gujarat state withan estimated overall loss of Rs. 28,423 crore. Thebrunt of the calamity was borne by five districts,namely Kachchh, Ahmadabad, Rajkot, Jamnagar andSurendranagar, where 99% of the total casualtiesand damage occurred. In the neighbouring parts ofSindhh Province of Pakistan, 40 human casualtieswere reported, whereas some buildings cracked inKarachi city as well. In the Kachchh District, thetelecommunication links and power supply remainedtotally disrupted, road and rail links partially impairedand water supply snapped at many places. The Bhujairbase had also to be closed for some time due todamage to the infrastructure. The macroseismicsurvey carried out by the Geological Survey of Indiain an area as large as 1.2 million sq km indicated theepicentral intensity as X on the MSK scale, thatoccupied an area of 780 sq km.

Apart from damage to civil structures, the 26 Januaryearthquake induced conspicuous terrain deformation

in the form of liquefaction features, structural grounddeformation and low order slope failures that weremainly prevalent within the higher intensity isoseists.Liquefaction occurred in an area of about 50,000 sqkm. The extensive plains of Rann of Kachchh, themarshy tracts of Little Rann and the shallowgroundwater table zones of Banni Land provided themost conducive geotechnical environments for thedevelopment of seismites. The liquefaction activitywas profuse in seismic intensity zones X and IX,widespread in intensity VIII, subdued in intensity VIIand stray in intensity VI. The common forms weresand blows/boils, ground fissures, craters, lateralspreading and slumping.

Ground deformation of tectonic origin was witnessedwithin the epicentral tract. Such features, thoughmuch less subdued in comparison with the 1819earthquake, occurred along the Kachchh Mainlandfault (KMF) and a transverse lineament, referred toas Manfara-Kharoi fault. The manifestations werein the form of fractures, displacement of strata, linearsubsidence, upheaval, formation of micro-basins/micro ridges, ripping off of rock surface and, at places,violent forms of liquefaction. The localities, wherethe coseismic deformational features were studiedby the author included Bodhormora, Sikra, Vondh,Chobari, Manfara and Kharoi.

The studies and documentation of 2001 Bhujearthquake has brought to light many significantaspects that may contribute to the understanding of

S1: Bhuj Earthquake and AftershocksConveners : B.K. Rastogi, Prabhas Pande and Jim Mori

THEMEThe 2001 M7.7 Bhuj earthquake is a rare great Stable Continental Region (SCR)earthquake studied through modern era seismographs. The well-determined mechanismindicated clear reverse faulting along a steep fault and inversion of tectonics from tensilestress (normal faulting) in the rift valley environment to compressive stress (thrusting)regime now. The rupture details have also been worked out. Over 10,000 aftershocks ofM 1-5 have been precisely located and well-studied by modern era local seismographnetwork. Seismological studies include PS, Q and b-value tomography, Crustal structure,through travel time, surface-wave dispersion and Receiver Transfer Function, anisotropystudy through shear-wave splitting, Geophysical surveys have established details of crustalstructure besides sediment thickness and basement configuration. All these studies havegiven new insights to the understanding of seismogenesis of least understood SCRearthquakes. Papers are invited on the study of Bhuj earthquake and aftershocks andsimilar earthquake in other SCR regions as a comparative study.


2 22 - 24 January, 2011

the seismotectonic behaviour and seismic hazardpotential of the dynamic landmass of Kachchh apartfrom providing an insight into the science ofearthquakes. The event has demonstrated in nouncertain terms the role of local geology in influencingthe ground motion characteristics and, therefore, thehazard estimation. The devastation caused by theearthquake has sent a strong message across varioussections of the stakeholders that there is an urgentneed to comprehend the seismic behavior of varioustectonic domains of India and formulate mitigationplans in accordance.

S1_Keynote-2

Delineation of crustal and lithospheric structurebelow the Kachchh rift zone: A probable modelfor the generation of aftershock activity for last10 years

Prantik Mandal (National Geophysical ResearchInstitute (CSIR), Hyderabad 500 007, India, E-mail:[email protected])

Large intraplate continental earthquakes like the1811-12 New Madrid (Mw≥8.0) and the 2001 Bhuj(Mw7.7) were highly destructive because theyoccurred in strong crust, but the mechanismsunderlying their seismogenesis are not understood.Here we show, using local earthquake velocitytomography, and inversion of P-receiver functionsthat the crust and uppermost mantle beneath the 2001Bhuj earthquake region of western India is far morecomplex than hitherto known through previousstudies. A new image of the crust and underlyingmantle lithosphere indicates the presence of a 18-km thick high velocity (Vp: 7.15 - 8.11 km/s)differentiated crustal and mantle magmatic layerabove a hot and thin lithosphere (only 70 km) in theepicentral region of 2001 Bhuj earthquake. Thismagmatic layer begins at the depth of 24 km andcontinues down to 42 km depth. Below this region,brittle-ductile transition reaches as deep as the Moho(~34 km) due to the possible presence of olivine richmafic magma. Our 1-D velocity structure reveals abasaltic magmatic eclogitic layer at sub-lithosphericlevels. This study also delineates an updoming ofMoho (~ 3-7 km) as well as asthenosphere (~ 6-12km) below the Kachchh rift zone relative tosurrounding areas, suggesting the presence ofpatches of partial melts below the lithosphere-

asthenosphere boundary. Restructuring of this warmand thin lithosphere may have been caused due torifting (at 184 and 88 m.y. ago) and tholeiitic andalkalic volcanism related to the Deccan Traps K/Tboundary event (at 65 m.y. ago). Recent study ofisotopic ratios proposed that the alkalic basalts foundin Kachchh are generated from a CO2 rich lherzolitepartial melts in the asthenosphere that ascended alongdeep lithospheric rift faults into the lithosphere. Itappears that such kind of crust-mantle structure,deepening of brittle-ductile transition and a high inputof volatiles containing CO2 emanating from mantlecontrol the generation of aftershock activity in theKachchh rift zone for last 10 years.

S1_Keynote-3

Seismic Source of the 2001 Bhuj Earthquake:A Review of Seismic Tomography, FractalDimension and b-value Mapping

J R Kayal (Indian School of Mines, Dhanbad826004, E-mail:[email protected])

More than 800 aftershocks (M > 2.0) were recordedduring the first two months after the January 26,2001 Bhuj earthquake (Mw 7.7) in western part ofthe peninsular Indian shield. About 500 aftershockswere relocated by simultaneous inversion using theLocal Earthquake Tomography (LET) method(Kayal et al., 2002, GRL). Most of the aftershocksoccurred in a V- shaped area of 70 x 35 sq km; themaximum activity was observed at a depth range of12-37 km. A bimodal distribution of aftershocksindicated that the main shock rupture propagated bothin the upward and downward directions, but therupture did not reach the surface. 3D-velocityvelocity structures imaged two fault zones withlower velocity, and a high velocity structure withhigher Vp/Vs at the fault ends, at the main shocksource depth. Aftershock trends and fault planesolutions are comparable with these two fault/rupturezones at depth.

Using the relocated events, b-value and fractalcorrelation dimension (Dc) mapping are studied(Das and Kayal, 2010, BSSA, submitted). Thesurface map of b-value as well as an E-W crosssection reveals two distinct NE and NW trendingtectonic arms of the V-shape aftershock zone. AN-S cross section, on the other hand, clearly imaged

322 - 24 January, 2011


the b-values of the known fault zones at depth. Thegeologically mapped known South Wagad faultshows a distinct lower b-value (0.8-1.1) zonecompared to the much higher value (1.4-1.8) at theKutch Mainland fault at depth. The images indicatethat the main shock and the aftershocks occurred atthe lower b-value zone or highly stressed zone atdepth. The fractal dimension Dc also differs (2.77and 2.64) for the two arms of the aftershock zone.These values as well as the overall Dc value 2.28for the entire aftershock zone are much higher thannormally observed values (1.0-1.8) in a seismicallyactive area, which implies a fraction 3D structure ofthe Bhuj earthquake source zone.

S1_I1

Impact of the 2001 M 7.7 Bhuj earthquake onhazard estimates in the United States

Mark Petersen (U.S. Geological Survey, Golden,CO, USA, E-mail: [email protected])

The U.S. Geological Survey develops seismic hazardmaps for stable-craton and extended-margin regionsof the central and eastern U.S. These maps formthe basis for building design codes, risk assessments,and public policy decisions. Input parameters forthese sources rely on “best available science” butare controversial due to lack of instrumentally-recorded strong motion data and recurrenceinformation. For example, the New Madrid regionof the central U.S. has experienced historical andprehistorical large earthquakes but the seismic hazardis vigorously debated because the interpretations ofthe limited data incorporate large uncertainties. In1811 and 1812 three large-magnitude earthquakesruptured in the New Madrid zone and causedwidespread damage and effects. However, fewpeople lived in the region at this time and a limitednumber of accounts describe the effects of strongground shaking. Paleo-liquefaction evidence showsthat this region has experienced repeated similarsequences of large earthquakes over the past fewthousands of years with a mean recurrence time ofabout 500 years. However, the rate of futureearthquakes is questioned because GPS velocity dataover the past decade indicate persistent low strainrates. Moreover, the estimated magnitude of thesehistorical events ranges from 6.8 to 8.0, basedprimarily on interpretations of intensity data and

liquefaction distributions. Hough et al. (2002) andTuttle et al. (2002) suggest that liquefaction data fromthe largest earthquake of the 1811-1812 sequenceare consistent with the Bhuj liquefaction fieldsuggesting a similar magnitude. The Bhuj earthquakeis thought by some to be a reasonable analog to the1811-1812 New Madrid earthquakes since that eventoccurred about 400 km from the plate boundary inan intraplate area characterized by low backgroundseismicity. The Bhuj aftershock distribution extendedover an area about 40 km × 40 km below the surface(Gahalaut and Burgmann, 2004), a much smaller areathan that for typical M 7.7 plate-boundaryearthquake. This observation demonstrates that largeearthquakes can occur on a relatively short faultsegment, similar to previous interpretations of theNew Madrid sources. Bhuj aftershocks extend downto 45 km (Mandal et al., 2004), which is deeper thanmost aftershocks recorded in interplate regions. Thisobservation provides evidence for significant ruptureareas required to cause large earthquakes with largestress drop (Singh et al., 2003). In addition, strongground motions for the Bhuj earthquake fromseismoscope data indicate that the seismic wavesattenuate slower than those from similar-size plate-boundary earthquakes near plate boundaries. Thisis consistent with intensity data in the central U.S.Hypothesized ground motions are also consistentwith ground-motion models developed from syntheticground motions for cratonic regions. Without the Bhujearthquake, it would be difficult to predict thecharacteristics of intraplate earthquakes where largeearthquakes are rarely observed. Studies of this eventare critical for estimating seismic hazard in lowseismicity intraplate regions.

S1_I2

Targeting the Future Great Earthquakes:

Global Monitoring and the 26 January 2001Bhuj, India Case.

Vladimir G. Kossobokov1,2

(E-mail: [email protected]),Leontina L. Romashkova1, and Anastasia K.Nekrasova1 (1 International Institute ofEarthquake Prediction Theory and MathematicalGeophysics, Russian Academy of Sciences, 84/32Profsoyuznaya Street, Moscow 117997, RussianFederation, 2Institut de Physique du Globe deParis, Paris, France.)


4 22 - 24 January, 2011

Our understanding of seismic process in terms ofnon-linear dynamics of a hierarchical system ofblocks-and-faults and deterministic chaos, hasalready led to reproducible intermediate-termmiddle-range earthquake prediction techniqueconfirmed by statistical testing in the on-goingregular forward application started in 1992. Theanalysis of seismic sequences within space-timeof long-, intermediate-, and short-term scalesevidence consecutive stages of inverse cascadingof seismic activity to the great shock and directcascading of aftershocks. The first may reflectcoalescence of instabilities at the approach of acatastrophe, while the second indicates a certainstate of readjustments in the system after it.

The 26 January 2001 Bhuj (Gujarat, India) greatearthquake happened just outside the territoriesconsidered in the Global Test of the algorithm M8(Healy, J. H., V. G. Kossobokov, and J. W. Dewey,1992. A test to evaluate the earthquake predictionalgorithm, M8,U.S.Geol.Surv.Open-FileReport92-401;URL http://www.mitp.ru/en/restricted_global/2001/2001am8.html), next to the edge of the circleof investigation, which was in Time of IncreasedProbability, TIP, for a magnitude M8.0+ eventbefore 2003 diagnosed in the regular 2001a Update(dated January 09, 2001) using the USGS/NEICGlobal Hypocenter Database through 2000. Wepresent characteristics of spatially distributed seismicflux dynamics within long-, intermediate-, and short-term scales in advance and after the 26 January 2001Bhuj earthquake, in particular those measures, whichwere used for the M8 algorithm diagnosis.

S1_I3

Relocation of Aftershocks of the 2001 BhujEarthquake Using Temporary Array Data.

Jim Mori1 (E-mail: [email protected]),Hiroaki Negishi2, and Tamao Sato3 (1DisasterPrevention Research Institute, Kyoto University,2National Research Institute for Earth Science andDisaster Prevention., 3Faculty of Science andTechnology, Hirosaki University)

We use the aftershock arrival time data that wererecorded during February 28 to March 6, 2001, on atemporary array of short-period seismographs, torecalculate aftershock hypocenters. There are a total

of over 1400 events (M0.5 to 3.5) with recorded Pand S waves on 5 to 6 stations. We try using differenttechniques, including a three-dimensional velocityinversion and hypoDD to investigate the pattern ofthe aftershock distribution. We also use crosscorrelation of waveforms to try and improve theaccuracy of the arrival times. Since the aftershockdistribution is relatively deep (10 to 35 km), it isimportant to use both P and S waves to obtain anaccurate estimate of the hypocenters. Theaftershocks are distributed over a relatively smallarea for an Mw 7.7 earthquake. The inferred smallfault area implies a relative high static stress drop of10 to 20 MPa.

The results of the relocations show a clearer imageof the fault plane compared to the previous locationsthat used only a one-dimensional velocity structure.The aftershocks show a plane that dips toward thesouth, similar to previous results, which is inferredto be the mainshock fault plane. There is still a rathercomplex pattern to the aftershock distribution thatshows a large number of off-fault events.

S1_C1

Probabilistic assessment of earthquake hazardsusing method of moments in the Kuchchh(Gujrat), India region of January 26, 2001earthquake

Jayant N. Tripathi (Department of Earth andPlanetary Sciences, University of Allahabad,Allahabad - 211002, India,[email protected].)

The Kuchchh region of Gujrat is one of the mostseismic prone areas of India, which has experiencedtwo large catastrophic intraplate, stable continentalearthquakes of magnitude Mw 7.8 & 7.7 in 1819 &2001, respectively. Several moderate and largeearthquakes also occurred in the region during lasttwo centuries. The observed recurrence timebetween the large earthquakes (magnitude e” 6.0),which occurred during last 200 years have been usedto estimate the probabilities of occurrence of nextearthquake in a specified interval of time for differentelapsed times using three probabilistic models,namely, Weibull, Gamma and Lognormal. Theparameters of the statistical models have been

522 - 24 January, 2011


estimated using method of moments (MOM). Theestimated cumulative probability reaches 0.8 afterabout 47 years for all the models while it reaches0.9 after about 53, 54 and 55 years for Weibull,Gamma and Lognormal model, respectively. Theconditional probability reaches 0.5, is in the years2037.32, 2036.06 and 2035.51 for the Weibull,Gamma and Lognormal models, respectively,however, it reaches about 0.8 to 0.9 for the timeperiod of 50 to 60 years for all the models.

S1_C2

Detection Complex Networks of BHUJEarthquake (2001) and Aftershocks by UsingSelf –Organizing Neural Networks

Mostafa Allameh-Zadeh (SeismologyDepartment, The International Institute ofEarthquake Engineering and Seismology, IIEES,27 Arghavan St. N. Dibajie, Farmanieh, 19531,Tehran, I.R.Iran.E-mail: [email protected])

This paper focuses on the shapes of clusters ofBHUJ earthquake that can be visualized in theirnetwork based on distance between two events (thepairs of linked neighbors). The knowledge can beextracted from the number of aftershocks and linksin their networks.We find that there is strongcorrelation in Iranian plate region, and that smallearthquakes (Ms>4.5) are very important to thestress transfers. It is demonstrated that the syntheticclustering in space and time of earthquakes is usefulfor seismic hazard assessment and intermediate-range earthquake forecasting by using Self-Organizing Neural networks.

The method has been tested for different cases astraining phase. In this mode, the actual output of aneural network is compared to the desired output.The network then adjusts weights, which are usuallyrandomly set to begin with, so that the next iteration,or cycle, will produce a closer match between thedesired and the actual output. The learning methodtries to minimize the current errors of all processingelements. This global error reduction is created overtime by continuously modifying the input weights untilacceptable network accuracy is reached. Withsupervised learning, the artificial neural network mustbe trained before it becomes useful. Training consists

of presenting input and output data to the network.This data is often referred to as the training set. Thatis, for each input set provided to the system, thecorresponding desired output set is provided as well.In most applications, actual data must be used. Thistraining phase can consume a lot of time. In prototypesystems, with inadequate processing power, learningcan take weeks. This training is considered completewhen the neural network reaches a user definedperformance level. This level signifies that thenetwork has achieved the desired statistical accuracyas it produces the required outputs for a givensequence of inputs.

S1_P1

Ground Deformation and LiquefactionStructures formed due to 2001 KachchhEarthquake on the Sabarmati River bed nearvillage Motiboru, Ta. Dhandhuka, Dist.Ahmedabad, Gujarat, India.

R.D. Shah, N.Y. Bhatt and P.M. Solanki(M.G. Science Institute, Navrangpura,Ahmedabad – 380 009.E-mail : [email protected])

Sabarmati River is one of the major rivers of Gujarat,originating from the Aravalli mountains anddebouching in the Gulf of Khambhat.

Motiboru village is situated on the banks of Sabarmatiriver about 80 km in SSW of Ahmedabad near theGulf of Khambhat.

Earthquake of 6.7 magnitude intensity on Richterscale having epicenter near Bhachau whichdevastated the entire state and adjacent states alsoleft its effects in form of deformation and liquefaction.These seismic features have occurred along theSabarmati river bed south of Ahmedabad which havebecame more distinct near Motiboru village.

Here on the river bed and on the bank region in thefields, liquefaction structures were formed during2001 Kachchh earthquake. The structures werecovering an area of about 0.5 km width and 2.5 kmlength within the riverbed and on the left bank regionon east side, near Motiboru village.

Ground deformation was observed in form of wideopen and displaced elongate ground fissures(lurching) indicating lateral spreading.


6 22 - 24 January, 2011

The liquefaction structures formed during the 2001Kachchh earthquake event were in form of sandblows, sand holes, sand domes, sand and mud dykesand dish structures. The structures are 0.3 m to 1.5m in diameter and dykes extend up to a distance of>15 m and discontinuously found up to 1.5 km. Thestructures indicate liquefaction of unconsolidatedsediments at comparatively shallow depth. Theliquefaction had occurred due to earthquake shocks.

Consequent to the earthquake very prominent groundfeatures were produced even at a distance of morethan 250 km away from the epicenter. This clearlyindicates seismic wave tapping and seismic waveamplification in the southern part of Cambay basin.

S1_P2

Seismicity Monitoring of Bhuj Aftershocks

Santosh Kumar, Sandeep Aggarwal, VandanaPatel, Kishan Zala and B.K. Rastogi (Instituteof Seismological Research, Gandhinagar)

Bhuj aftershocks are being monitored by ISR fromAug 2006 with Gujarat State Seismic Network of50 broadband seismographs (19 connected withVSAT) and 50 strong motion Accelerographs. Thedetectibility is M1.0 in Kachchh, M2.0 in Saurashtraand M2.5 in other areas. In Kachchh 2401 shocksof M3-3.9, 357 shocks of M4-4.9 and 20 shocks ofMe”5.0 have occurred during 2001-2010. In thisregion M5.7 level seismicity continued until mid 2006.

From mid 2006 there is no shock of Me”5.0, howevershocks of M<5.0 are continuously occurring. ISRlocated 52 shocks of M4.0-4.8, 714 shocks of M3-3.9 and 5298 shocks of M<3.0 during 2006-2010.Presently more than 2000 shocks per year of Me”0.5are being recorded from Kachchh and 80% areprecisely located. Initially hypocenters are locatedusing Seisan program and local velocity model ofMandal (2004) determined by tomography and thenrefined with HypoDD. With Seisan horizontal erroris less than 1-2 km and vertically less than 2-3 km.With HypoDD accuracy is within few hundredmeters. Most of the aftershocks are confined torupture zone (along the North Wagad Fault) of 2001Mw7.7 earthquake. In 2001 the earthquakes wereconfined in an area of 20 km x 20 km. Thoughseismicity reduced from 2002, there was a spurt ofincreased activity for the two years period of 2005-2006. During this period activity migrated to theWagad area towards east and Gedi fault to thenortheast. The seismicity area increased to roughly60 km x 70 km during 2005-2006. In 2008 BanniFault, north of KMF become active with Mmax.4-4.5 earthquakes. On Banni Fault M4.5 occurred on28th October 2009. In 2010 shock of Mmax4.1 waslocated on 11th August 2010 along North WagadFault. All other shocks are of M<4.0.

Also in 2006 on Island Belt Fault earthquake of M5.0occurred on 3rd Feb 2006.

722 - 24 January, 2011


S2_Keynote-1

Seismotectonics of Bhuj Earthquake of 2001based on Gravity and Magnetic signatures- ANear Plate Boundary Earthquake and itsComparison to New Madrid Seismic Zone, USAand Shillong Plateau, India

D.C. Mishra (National Geophysical ResearchInstitute (CSIR), Hyderabad-500007.E-mail: [email protected]: 0091 40 23434670;Fax: 0091 40 23434651)

Kutch is a Mesozoic rift basin where Jurassic andCretaceous sediments are exposed. The two majortectonic events that have affected this section is the

break up of Africa and Seychelles due to Karoo andDeccan trap volcanic, respectively. Though, thereare no exposures of Karoo volcanics in India but itmight be overlain by Deccan trap that was quitewide spread. However, in Lodhika parametric wellfor oil exploration in Saurastra, a second level ofvolcanic rock below Deccan trap has been reported.Jurassic rift basin of Kutch might have formed dueto extension caused by Karoo volcanics as both arecontemporary. Subsequently, it was uplifted duringclosing phase of the basin that resulted into variousuplifted blocks such as Kutch Mainland Uplift(KMU), Wagad Uplift (WU) etc. These uplifts mighthave been accentuated due to Karoo intrusive in thebasement during closing phase of the basin that gives

S2: Intraplate SeismicityConvener : O. P. Mishra

THEMEThe Earth’s most seismically active regions and sites of its largest earthquakes coincidewith the boundaries between the tectonic plates. However, the vast majority of the earth’ssurface and continents lie within the interiors of these tectonic plates, and ‘intraplate’regions can also exhibit significant earthquake activity. Despite advent of modernseismological research, the seismogenesis in the intraplate regions of the world, includingStable Continental Region (SCR) of India is still a great puzzle for geoscientists to explorethe plausible mechanism involved into intraplate seismicity. The identity and characteristicsof their seismic sources remain unknown. The explanation for the intraplate seismicitynecessitates understanding of the evolution, structures and processes of the shield area.Several sets of hypotheses and theories without common consensus on genesis ofinpraplate seismicity have been developed and put forth by different researchers fordifferent intraplate regions of the globe (e.g., Africa, Asia, Australia, Europe North Americaand South America). Moreover, the frequent occurrences of the 1993 Latur – Killari (Mw6.3), the 1997 Jablapur (Mw 6.0), and the 2001 Bhuj (Mw 7.6), Indian earthquakesbeneath the intraplate stable continental regions of the Peninsular India ushered a newera of integrated seismological research coupled with multi-disciplinary geo-scientificobservations to address the physics of intraplate seismicity. The focus of this session on“Intraplate Seismicity” is to understand the nature of intraplate seismicity and the forcesdriving it in the ‘stable continental regions’ of the world in general, and in ‘peninsularIndia’ in particular. Considering significant advances on intraplate seismicity researchin recent years, the session on “intraplate seismicity” invites case studies on recentsignificance earthquakes and swarm activity in the peninsular India and the regions ofanalogous geotectonic settings, elsewhere in the world. Presentations on seismotectonicprocesses, crustal 1-D and 2-D velocity and attenuation models, and studies of regionaland local stress patterns with integrated seismo-geophysical interpretation frame workderived from multi parametric seismo-geophysical observatories are also invited. Inaddition, contributions on ground motion observations from intraplate earthquakes andefforts to model sub-surface seismogenic layers using local and regional 3-D velocityand attenuation tomography are also welcome.


8 22 - 24 January, 2011

rise gravity highs over them in spite of thick sedimentsof low density in these sections. The gravity field ofthe Kutch suggests an over compensated crustcausing present day uplift of the KMU and WU.Coupled with the plate tectonic forces in directionof the plate motion, it has resulted in to consistentlyrising basement towards north along reverse faultsthat are seismogenic. Airborne magnetic map of thisregion shows two sets of long linear magneticanomalies indicating mafic intrusive that intersect inthe epicentral area of the Bhuj earthquake. Circular/semicircular gravity anomalies of Pachham, Khadirand Bela uplifts indicate plug type intrusive for them.Lineament map of Pakistan suggest that some ofthem extend from Kutch to the western boundaryof the Indian plate. These observations suggestfollowing factors for enhanced and large magnitudeearthquakes in this region inspite of being in stablecontinental regions.

i. Over compensated crust causing uplift coupledwith present day plate tectonic forces causingnorthwards uplift of the basement along variousreverse faults

ii. Large scale magmatism weakening the crustalfabric.

iii. Lineaments/structural trends extending to thewestern boundary of the Indian plate that is atransform fault known as Chamman fault.

The last point indicates that the Bhuj earthquake cannot be considered purely Stable Continental Region(SCR) earthquake and can be termed as ‘Near PlateBoundary’ or ‘Diffused Plate Boundary’ earthquake.Other sections in stable continental region that haveexperienced large number and magnitude of seismicactivity are New Madrid Seismic Zone in USA andShillong Plateau, India. Similarities between them arepresented in course of the presentation during theworkshop.

S2_I1

Geodynamics of the Kachchh Basin: Gravity-Magnetic Perspective

D.V. Chandrasekhar and B. Singh(E-mail: [email protected],National Geophysical Research Institute (CSIR),Hyderabad 500 007)

Gravity and magnetic data of the Kachchh basin and

adjoining regions have delineated major E-W andNW-SE trending lineaments and faults, some of thateven extend up to plate boundaries at north ArabianSea and western boundary of the Indian plate. Theimbricate fault system due to Bhuj 2001 earthquakewas clearly deciphered by the detailed gravity andmagnetic anomaly map of Kachchh which is differentthan the Kachchh Mainland Fault (KMF). Bougueranomaly map depicts that the epicentral zone of Bhujearthquake is located over the junction of Rann ofKachchh and median uplifts viz. Kachchh mainlandand Wagad uplifts, which are separated by thrustfaults. Modeling of gravity and magnetic data withconstraints from seismic studies suggest that thebasement is uplifted towards the north across thrustfaults dipping 40-60o south. A south dipping (50-60o)basement contact separates blocks of highsusceptibility / high density under the northern partof the Wagad uplift ( E-W oriented North Wagadthrust fault (NWF) ) exactly coincides with the faultplane of the Bhuj earthquake as inferred fromseismological studies. A circular gravity high overthe Wagad uplift suggests a plug type mafic intrusivein this region and several such gravity anomalies areobserved over the island belt which is analogous tothe gabboric intrusion along the Commercegeophysical lineament of the New Madrid seismiczone. The contacts of these intrusive with the countryrock demarcate shallow crustal inhomogeneities, aregion of possible stress concentrator and excellentsite for the accumulation of regional stresses. Aregional gravity anomaly map based on the conceptof isostasy presents large wavelength gravity lowsof about -13 mGal in the epicentral region. Theirbest-fit model suggest the presence of two centersof mass deficiency representing thick crustal root of7-8 km (deep crustal inhomogeneity) for a standarddensity contrast of -400 kg/m3 which could beintimately related to seismicity in Kachchh similar toMissori gravity low in the case of New Madridseismic zone.

Soon after the Bhuj earthquake repeat gravity andelevation measurement were carried out to find anycrustal deformation. Height and gravitymeasurements observed along a profile across theepicentral area before and after the January 26, 2001,Mw 7.6 Bhuj earthquake show a maximum uplift of+1.57 ± 0.46 m and a gravity decrease of –393 ± 18

922 - 24 January, 2011


μGal. A best-fit, single dislocation model of the Bhujearthquake rupture inverted from the height-changeobservations using non-linear optimization methodsindicates that the high-slip rupture was well containedin the aftershock zone and likely did not break todepths shallower than ~10 km. The earthquakesource parameters arrived in the present studyagrees well with those provided by fault planesolutions, teleseismic finite-slip inversions and thedistribution of aftershocks. The gravity data over theepicentral area are well modeled by the preferredmodel; however, a strong influence of shallowhydrological processes on the observed changes isinferred for three sites located on the Banni plainsto the west, wherein the mean gravity change of+275 μGal suggests a total mass redistribution of asmuch as 2.9 Mt. In view of above it is inferred thatsignificant amount of stresses gets accumulated inthis region due to presence of (a) thick crustal root(b) stresses at the periphery of mafic intrusive, and(c) regional stresses due to plate tectonic forces.

S2_C1

Geodetic crustal strain patterns over theSatpura Mountain Belt: Implications for thetectonic controls of stable continental interiorseismicity

S. Mohanty (Department of Applied Geology,Indian School of Mines, Dhanbad 826004, IndiaEmail: [email protected])

The Satpura Mountain Belt forms an ENE–WSWtrending zone in the central part of India. This Mountainbelt located in the Indian plate interior is an ancientorogenic belt of Precambrian age. It has high seismicityin the present time. The crustal strain rates weredetermined from the changes in positions of geodetictriangulation points in selected areas of the SatpuraMountains during last 87 years and 130 years. Amaximum extension rate of +600 X 10-9 year-1

towards N152°-N332° and maximum shortening rateof -317 X 10-9 year-1 along N028°-N208° weredetermined from the studied areas. The strain ratesare comparable to the average strain rates of thecontinental rift-systems. Detailed analysis of the spatialvariations of the strain rates establishes the relationshipbetween the high-strain areas with the regionalmovement patterns across the Satpura Mountains.

The crustal strain determined from the GPS data ofthe sites in Peninsular India corroborates the strainrates from the GTS monuments. The long distancesites located across the Satpura Mountains showvery low amount of NS shortening ( 1.1 X 10-9 year-

1), and moderate amount of EW extension (+4.9 X10-9 year-1). However, a detailed analysis brings outlocal details. The regions south of the SatpuraMountains show very low amount of NS shortening( 1.7 X 10-9 year-1) and moderate EW extension(+3.7 X 10-9 year-1). The Satpura Mountain belt hasmoderate shortening rate in NS direction ( 2.0 X 10-

9 year-1) and moderate extension rate in EW direction(+3.2 X 10-9 year-1). The region north of the SatpuraMountains shows moderate extension rate along NSdirection (+6.6 X 10-9 year-1) and high EW extension(+10 X 10-9 year-1). Moderate shear strain rates aredetermined from all the sectors of the analyzed region(3.7 to 6.0 X 10-9 year-1).

The regional variations in the pattern of the crustalstrains across the Satpura Mountains is interpretedto be the result of obliquity of the ancient mountainbelt with respect to the plate motion of the Indianplate. This obliquity is responsible for partitioning ofstrain regime to normal and shear stresses acrossthe Satpura Mountains. The curvilinear trend of thebelt is expected to give rise to local transpressionand transtension for regional seismicity of the centralIndia. Similar mechanisms may be in operation inother zones of high seismicity in stable continentalinteriors.

S2_C2

Mafic Crust and Earthquake Activity in theHigh Velocity Indian Shield

O.P. Pandey (National Geophysical ResearchInstitute, Uppal Road, Hyderabad-500007, India.E-mail: [email protected])

Dynamic Indian subcontinent with active history ofrifting and multiple plume interactions is consideredunique among stable areas of the Earth. It containsseveral rift valleys and mega lineaments which havebeen repeatedly rejuvenated since at least 1.5 Ga.Continued reactivation / rifting over such a longperiod of time is hardly seen elsewhere. It istherefore, not surprising that the Indian stablecontinental region has been frequently experiencing


10 22 - 24 January, 2011

moderate seismic activity since a long time, whichincludes 14 events of magnitude 5 or more in thelast 50 years. Many of these earthquakes weredestructive in nature leading to heavy loss of humanlife and property, like Anjar (Mw 6 ,1956), Koyna(Mw 6.3 ,1967), Latur (Mw 6.3 ,1993) and Bhuj (Mw7.7 ,2001) etc . The last two events alone claimedmore than 30,000 human lives. Inspite of largenumber of studies, cause of recurring seismic activitystill remains a subject of considerable debate.

Our detailed study of important earthquake localitiesindicates quite high P- and S- wave velocities (6.2 –6.7 km/s and 3.65 – 3.90 km/s respectively) at ashallow depth of almost surface to six kilometers.These seismogenic regions appear to be in a stateof continuous uplift and erosion since geologicaltimes, which led to shallow surfacing of mafic(amphibolitic-granulitic) crust in which stresses tendto accumulate due to ongoing local upliftment and ahigh input of heat flow from the mantle. Thesestresses are apparently acting over and above to theregional compressive stresses generated by India-Eurasia collision.

S2_C3

An Intraplate Earthquake and the study ofGround Response Analysis using EquivalentLinear Method -a case study of NCT Delhi.

H.S.Mandal (Earthquake Risk Evaluation Centre,India Meteorological Department, New Delhi, [email protected])

Amplitude of earthquake ground motion is affectedby both the properties and configuration of the nearsurface material through which seismic wavespropagate. The study of earthquake responses i.e.evaluation of peak frequency and frequencydependent amplification of a site is very importantparameter from engineering aspect to formulateseismic code to construct earthquake resistancestructures. The peak frequency and amplificationvaries from place to place due to the variable soilproperties and thickness, which reveals in the specialvariation of damage pattern observed in a city duringthe big earthquake. This is basically non linearity ofthe soil underlining below the structure. The studyof non linear behavior of the soil deals the way ofthe stress-strain changes of the material due tocertain initial exerted stresses. The characteristic of

normalized shear modulus (G/G0) and damping (h)also changes accordingly with increase of strain. Thenumerous studies reveal that the non-linear behaviorsoccurred only the alluvium deposit sites. The Silt,Sand, silt-Sand, Sandy-silt, Clay material are exampleof earthquake hazardous type of soils.

The archeological survey reveals that the Yamunahas changed its course during last several hundredyears and migrated eastward keeping flood plains inthe left. The Delhi, National Capital of India nowextends over swamps and recent fluvial deposits onthe banks of the River Yamuna. Apart from theflood plain area a vertical ridge which is passing alongthe SSW to NNE direction in the center part of theNCT Delhi. The ridge is exposed at some placeswith characteristics of weathered rock at the surface.The identification of this complex geological variationand bed rock depth is essential for precisedetermination of soil responses.

In this paper an attempt has been made to find outthe soil response parameters over few places of NCTDelhi. The prerequisite of the study are (i) the inputearthquake motion at the rock level and (ii) the soilcolumn information just above the rock level atdifferent sites.

An intraplate earthquake of magnitude 4.3 in Richterscale, occurred on November 25, 2007 at Delhi-Haryana Broader region (lat 28.60°N, long 77.00°Eand focal depth 20.3km) and Acceleration timehistory recorded at Ridge observatory of IndiaMeteorological department which is about 20km farfrom the earthquake source has been considered forthis study. This observed acceleration time historytaken as a key input for soil response studies.

The exploratory drilling undertaken by variousagencies has brought out the subsurface configurationof rock formation and depth to bedrock in differentparts of Delhi region. The nature of bedrocktopography is rendered uneven due to the existenceof subsurface ridges. Thickness of alluvium overlyingthe quartzites increases away from the outcrops. Inthe city block, west of the ridge, the alluvium thicknessincreases away from the ridge to 300 m or more.East of the ridge, in the area up to River Yamuna,the alluvium thickness is comparatively less to about165 m. East of the River Yamuna covering parts ofthe city and Shahdara blocks, the thickness ranges

1122 - 24 January, 2011


from 48 to 240 m. This information has been used todetermine soil column information up to differentdepth as a second parameter of the study.

The soil column is demarcated by few layers withdepth depending upon the thickness of the soil. Theeach layer material properties are defined as density,shear wave velocity (Vs), shear modulus (G) anddamping (h) as input parameter. The soil responsesare evaluated at every one km interval along twoprofiles (i) north-south direction i.e. from ISBT (InterState Bus terminal) to Sewanagar and (ii) east-westdirection from Tilak Bridge to Punjabi Bagh. Theclose intervals are taken to check the soil amplificationor de-amplification criteria along the profile withvariable soil depth. The Equivalent Linear Method(ELM) is applied to find the earthquake response atthe level ground surface.

The yielded peak frequency from the amplificationspectra at the ground surface and the Fourierresponse spectra of the input signal are comparedand agreed well with each other. The peakamplification varies from 4.2 to 5.9 and correspondingpeak resonance frequency varies from1.2 to 5.3Hz.The more value of peak amplification factor is foundat thicker alluvium deposit site with less frequencycontains ground motion and vice versa.

Key words: Equivalent Linear Method,amplification, peak frequency, base rock, soil model,SMA, Intraplate earthquake.

S2_C4

Study of the Shallow Seismic Activity OffshoreSouthern and Eastern Sri Lanka

Shantha S.N. Gamage and S.A.D.L.K.Suraweera (Department of Physics, University ofSri Jayewardenepura, Sri Lanka)

Sri Lanka is considered to be in an aseismic zoneaway from major plate boundaries or any activefaults. However during the last century, there havebeen several hundreds of earthquakes and earthtremors reported in and around Sri Lanka. Some ofthese events are described in historical records andmore recent events have been identified by institutionssuch as United States Geological Survey (USGS),and other global seismic networks. Theseearthquakes have been categorized as shallow andintermediate depth earthquakes. Although this type

of earthquakes have been occurring specially in theoffshore region of Sri Lanka, detailed investigationof their activity in this region has not been carriedout. We therefore made an attempt to investigateearthquake activity of offshore region of the easternand southern Sri Lanka which is seismically active.

We analyzed the shallow seismic activity of offshoreof eastern and southern parts of Sri Lanka andidentified their focal mechanisms. We obtainedhypocentral data from the Data Management Center(DMC) at the Incorporated Research Institutions forSeismology (IRIS). The earthquake list distributedby the IRIS DMC made clear that there aresometimes multiple epicenter estimates for a singleearthquake. We identified those errors and calculatedthem relative to the NEIC catalog epicenter. Sincethere are mislocations of events, we tried to identifythe magnitude of those errors. Then we analyzedthe seismic activity region by region. Our findingshows that large number of earthquakes takes placeat a belt lie in southern part of offshore Sri Lankaalthough some events are scattered due to locationerrors mentioned above.

The focal mechanism data obtained from HarvardCMT moment tensor catalogue were also analyzedfor the events occurring in the region. Althoughdifferent types of focal mechanism solutions exist inearthquakes of near coast events, we clearly notedthat earthquake belt in the southern part of Sri Lankahave mechanical solutions which is similar to that ofstrike slip fault mechanisms. It seems that thisseismically active region may belong to the boundaryof Indo-Australia plate.

S2_C5

Assessing the intraplate type generation ofsubduction zone mega-thrust earthquake withspecial reference to 2004 Sumatra eventMW9.3

Prosanta K. Khan (Department of AppliedGeophysics, Indian School of Mines, Dhanbad –826 004, India, Email: [email protected])

Subduction zone mega-earthquakes are traditionallythought to be caused by sudden stress-relievingdisplacements at the contact zone locked asperities(topographic highs/seamounts) between thedescending oceanic lithosphere and the overridingcontinental plate. Assessment of such six


12 22 - 24 January, 2011

earthquakes viz. 2004 off Sumatra, 1965 Rat Islands,1964 Alaska, 1960 Chile, 1957 Aleutians, 1952Kamchatka, however, reveals that the relationshipbetween interplate coupling and seamount subductionis rather ambiguous as estimated χ values varywidely. Further, the best ever recorded 2004 Sumatraevent argues the stationary model of asperitysubduction along the Sunda margin. With thisbackground the 2004 Sumatra mega-event wasstudied considering rheology and geometry as wellas the penetration of the slab through the mantle.

The present study proposes an intraplate modelfor mega-thrust earthquakes with failure of thesubducting oceanic slab, and suggests the flexing zoneof the descending lithosphere as the nodal area formajor stress accumulation. We believe that at highconfining pressure and elevated temperature,unidirectional cyclic compressive stress (arises dueto unbalanced component of slab resistive force)loading in the flexing zone results an increase ofmaterial yield strength through strain hardening, whichtransforms the rheology of the layer from semi-brittleto near-brittle state. The increased compressivestress field coupled with upward migration of theneutral surface under non-coaxial deformationtriggered shear crack on 26th December 2004preferably at the rheological interface betweenstrain-hardened near-brittle layer and deformedductile layer within the sub-oceanic mantle. Thesubsequent growth of the shear crack was initiallyconfined in the near-brittle domain, and propagatedlater through the more brittle crustal part of thedescending oceanic lithosphere in form of cataclasticfailure. This study warrants for an assessment offailure during large earthquakes within the continent,normally originated at depths between 10 and 25 km,and likely associated with the shallower strong elasticcore of the lithosphere.

S2_C6

Crustal Strain Pattern over a part of SouthernIndia and its implication for Seismotectonics.

Arijit Barik (Email:[email protected]) and S.Mohanty (Department of Applied Geology, IndianSchool of Mines, Dhanbad 826004, India)

The Indian Peninsula, in general and its southern partin particular, is considered to be a stable shield area.There is growing evidence that the Indian peninsular

shield is no longer a continental interior of low seismicactivity. The present study was carried out todetermine the relation between the strain rates overa part of South India and to identify possiblevulnerable areas to earthquake devastation.Computation of the lithospheric plate velocity fielddata for the South Indian Block has shown that thereis a significant amount of extensional strain alongthe EW direction whereas the NS direction hasnegligible amount of shortening strain. Thecomparative results of strain data for a number ofcomputation models and reference frames used inthe analysis show that the shear strain values in allthe models are high and are comparable to those ofthe continental rift system. These analyses suggestthat the deformation of the Indian plate is presentlyachieved by rotational deformation in anticlockwisedirection. Such a strain regime together with themovement of the Indian plate towards NNE to NEis likely to activate the regional faults aligned E-W,NE-SW and NW-SE. So this significant amount ofextensional strain component along EW direction isstretching the crust of the Indian Peninsula alongEW direction and making the crust weak andearthquake prone. The focal mechanism solutionsof some of the recent earthquakes in the regioncorroborate the computed strain patterns, and theNeotectonic activity expected in this model study.

S2_C7

Intermittent Micro-seismic Activity in theVicinity of Nanded city West Central India

Md. Babar Shaikh (Associate Professor,Department of Geology, Gyanopabok College,Parbhani-431401.P. O. Box No. 54, Maharashtrta,India. [email protected])

Among the earthquakes of the Deccan BasalticProvince, the Koyna earthquake of 1967 (M 6.3) andKillari earthquake in 1993 (M 6.2) were disastrous inWest Central India. Significant Earthquakes followedat Latur-Killari in 2005 and several times at Koyna.The present study area in the vicinity of Nanded City(Maharashtra state) has experienced a series of minortremors that have been felt since 13 November 2006.Based on media reports and on felt reports, activitiesin this sequence increased notably on 31 March 2007and reduced by May, picking up once again at the endof October continuing up to January 2008. The

1322 - 24 January, 2011


strongest events were felt on 31 March 2007, then on12 November 2007 and 14 December 2007 causingwidespread panic. The micro-seismic activity endedby January 2008. Over 500 events have been feltsince late 2006 to January 2008. Again the micro-seismic activity started in the month of October 2010with maximum felt event on 21st November 2010 at12.19 pm (MW 2.4).

The tremors are associated with subterraneanexplosive sounds. The residents in northern parts ofNanded town that has been hit by the tremors movedto safer areas or were staying outdoors intemporarily erected shacks in front of their housesduring the activity periods. The max.-magnitudeearthquake made widespread minor cracks ofhouses around the epicentral area in the Nanded city.The shocks are mostly confined to North andNorthwest of Godavari River. The spatial distributionof the local micro-seismicity of 2006-2008 eventssuggests that the NW-SE structure may be a potentialseismogenic structure.

About 69 tremors that occurred during the monthsof November and December 2007 have been locatedby 4 Broadband seismic stations in the epicentralregion and their locations coincide with the reportedregion of maximum ground shaking. Majority of theepicentres lie in an area of 12.5 sq. km (5kmX2.5km) between the Asna and Godavari Rivers and thedepth extent of this activity is limited to the top 3km. The NW-SE trend of the Asna River coincideswith the trend of the seismic activity indicating thatthe river course is being guided by a NW-SE trendinglineament. More over there is report of historical1942 earthquake of Mw 4.2 north of Nanded city.

S2_C8

Structural controls on the intraplate seismicityof the Kachchh region, India

Sushmita Sinha(Email: [email protected]) andS. Mohanty (Department of Applied Geology,Indian School of Mines, Dhanbad 826004, India.)

The Kachchh province of Western India is a majorseismic domain in an intraplate setup. The seismiczone is located in a rift basin, which developed duringthe early Jurassic break-up of the Gondwanaland.The neotectonic activity of the region is attributed to

the basin inversion phase. Detailed analysis of thefault patterns and crustal strain were carried out todetermine the tectonic controls on the seismicity ofthe Kachchh region. The regional faults of the studyarea have EW strikes, giving rise to highlandsextending in EW direction. These high areas areaffected by several transverse faults with NE-SWand NW-SE strikes. Crustal strain determined fromthe GPS velocity data of post-seismic time periodfollowing 2001 Bhuj earthquake, indicates amaximum strain rate of 300 X 10-9 /yr along N013°.Focal mechanism solutions of the main event of 26January 2001 and post-seismic events show themaximum principal stress axis close to this direction.Maximum shear strain rate determined from the GPSdata of the area has similar orientation. The unusuallyhigh strain rate is comparable in magnitude to thecontinental rift systems. The model velocity data forthe region corroborates the high strain regime of thestudy area (17.24 x 10-09 /yr). However, the modelstrain rate is relatively of low magnitude because ofvery long duration value taken for plate rotationparameters. The orientation of the principal stressaxes of focal mechanism solution data and the straindetermined from the GPS velocity field do not matchwith the plate velocity vectors of the Indian plate(46° towards N047°). This is interpreted to be theresult of partitioning of deformation into the strikeslip components parallel to the regional EW faultsand the normal component perpendicular to theregional faults. The transverse faults parallel to theanti-Riedel shear planes have become critical underthese conditions. These anti-Riedel planes areinterpreted to be critical for the seismicity of theKachchh region.

S2_C9

Improved Seismicity Trends in the Koyna-Warna Region through Earthquake Relocationusing hypoDD.

G. Srijayanthi (E-mail:[email protected]),Pinki Hazarika, M. Ravi kumar, D. Srinageshand N. Purnachandra Rao (National GeophysicalResearch Institute (Council of Scientific andIndustrial Research), Uppal Road, Hyderabad –500007)

The earthquake of M6.3 in 1967 near Koyna tops thelist of earthquakes triggered by reservoir, for the


14 22 - 24 January, 2011

largest and most damaging earthquake. This arealocated on the South Western part of Deccan VolcanicProvince called Koyna-Warna seismic zone isprominently known for its sustained seismic activitysince four decades. A network of 12 stations spanninga 20y!30 km area in the Koyna-Warna Region(KWR) is operated by National Geophysical ResearchInstitute, to monitor the activity. Hypocentres ofearthquakes recorded from February 2006 toDecember 2009 were located, using HYPOCENTREprogram. To understand tectonic processes,earthquake recurrence, and earthquake interaction, athorough analysis of seismicity and a very goodunderstanding of the spatial trends is essential.Especially the active faults can be readily identifiedusing microseismic distribution. Thus, to refinehypocentral locations, hypoDD, a double-differenceapproach for hypocentre locations is used, by whichthe rms (root mean square) error has been brought toan optimum level of 0.01 and errors in location, depthare limited to < 100 m. The new improved locationsshow clear trends of seismicity with focusedclustering, as compared to single event locations.Especially, the focal depth accuracies are improved,with minimum dependence on velocity modelsresulting in better constrained fault geometries.

S2_P1

Spatiotemporal Complexity of IntraplateSeismicity: a Reverie and its MultifariousImplications

Arjun Tiwari (Final Year, M.Sc.Tech (AppliedGeophysics) Indian School of Mines Dhanbad, E-mail [email protected])

Unlike at plate boundaries, where plate motions giveinsight into why and how often earthquakes occur,we have little idea of what causes intraplateearthquakes, and no direct way to estimate how oftenthey should occur. As a result, progress inunderstandings these earthquakes is much slowerthan for earthquakes on plate boundaries, and keyissues may not be resolved for very long time. Hence,the distribution of earthquakes in space and timewithin continental interiors is far more complex thanon major plate boundary faults.

Here situation is quite different withincontinental plate interiors, where earthquakes appear

to be clustered, episodic, and migrating in space.Continental intraplate seismicity provides one of ourfew ways of studying the limits of plate rigidity andintraplate stresses, and poses the challenge ofdeciding the appropriate level of earthquakepreparedness for rare, but potentially destructive,earthquakes. Moreover, we analyze thespatiotemporal exemplar of intraplate seismicity usinga finite element model. The model assumes tectonicloading, crustal failure and stress evolution. Here,we start with a simple model with horizontallyhomogeneous crust and then we consider timescale-dependent spatiotemporal exemplar of seismicity,effects of weak zones and fault weakening.

The complex variation of seismicity inspace and time poses a major challenge for seismichazard estimation. These exemplars of intraplateseismicity indicate that earthquake hazardassessment based on few historic records may beinclined towards overestimation as well asunderestimation.

S2_P2

Unusually large number of earthquakesequences in Saurashtra since 2006 due tostress pulse of 2001 M7.7 Bhuj earthquake.

B.K. Rastogi, Santosh Kumar and SandeepAggarwal (Institute of Seismological Research,Gandhinagar 382007)

After 2006, earthquakes of M3.0 to 5.0 with longsequences of foreshocks and aftershocks havestarted occurring in Saurashtra region of Gujaratstate at a number of places along small faults. Theseplaces are Sayla in Surendernagar district, Talala inJunagadh district, Adwana in Porbandhar andKhankotda, Kalavad, Sanala and Moti Khavdi areain Jamnagar districts. Shocks have recurred everyyear since 2006 in Jamnagar district, since 2007 inTalala, Junagarh district and since 2008 inSurendernagar district. These sequences occurredmostly during September to November after heavyrains. These shocks are felt with subterranean soundsand have depths of near surface to 8.0 km.Earthquakes of M4.8 and M5.0 which occurred inNov 2007 in Talala and M4.0 in Kalavad in September2006 caused damaged to number of houses. Theactivity of these areas was monitored by deploying

1522 - 24 January, 2011


local Broadband seismograph (BBS) networks. Theareal extent of the epicenters is 2 to 30 km. In 2000,Bhavnagar experienced damaging earthquake ofM4.2 and several earthquakes associated with longsequence. The seismicity in Saurashtra, during thecurrent decade is higher than as compared to last 20decades (barring the year 1938 when damagingearthquake of M> 5.0 occurred in Paliad, south ofcurrent activity in Sayla). The unusual seismicity inSaurashtra since 2006 is suggested to be due to stressincrease by delayed stress pulse transmitted byviscoelastic process from 2001 Bhuj M7.7hypocenter up to 200km distance in the south. Thesudden rise of water table by 30 m from pre to postmonsoon is inferred to cause 3 bars stress changewhich triggers small to moderate earthquakes.

S2_P3

New insight into crustal heterogeneity beneaththe 2001 Bhuj earthquake region of NorthwestIndia and its implications for rupture initiations.

A.P.Singh1 (Email:[email protected]),O.P.Mishra2 (Email:[email protected])B.K. Rastogi1 (1Institute of SeismologicalResearch (ISR), Raisan, Gandhinagar-382009,Gujarat. 2Geological Survey of India,27, J. L. Nehru Road, Kolkata-700 016 andSAARC Disaster Management Centre, NewDelhi-110002

The seismic characteristics of the 2001 Bhujearthquake (Mw 7.6) has been examined from theproxy indicators, relative size distribution (3D b-valuemapping) and seismic tomography using a new dataset to understand the role of crustal heterogeneitiesin rupture initiations of the 2001 Bhuj earthquake of

the Kachchh, Gujarat (India), one of the disastrousIndian earthquakes of the new millennium. Theaftershocks sequence of 2001 earthquake recordedby 22 seismograph stations of Gujarat SeismicNetwork (GSNet) during the period from 2006 to2009, encompassing approximately 80 km X 70 kmrupture area had revealed clustering of aftershocksat depth of 5 –35 km, which is seismogenic layerresponsible for the occurrence of continuedaftershocks activity in the study region. The 3D b-value mapping estimated from a total of 3,850precisely located aftershocks with magnitude ofcompleteness Mc e” 2.7 which shows that a high b-value region is sandwiched within the main shockhypocenter at the depth of 20-25 km and low b-valueregion at above and below of the 2001 Bhuj mainshock hypocenter. Estimates of 3-D seismic velocity(Vp; Vs) and Poisson’s ratio (á) structure beneaththe region demonstrated a very close correspondencewith the b-value mapping that supports the similarphysio-chemical processes of retaining fluids withinthe fractured rock matrix beneath the 2001 Bhujmainshock hypocenter. The overall b-value isestimated close to 1.0 which reveals thatseismogenesis is related to crustal heterogeneity,which is supported by low-Vs and high- á structures.The high b-value and high-á anomaly at the depth of20 - 25 km indicate the presence of highly fracturedheterogeneous rock matrix with fluid intrusions intoit at deeper depth beneath the main shock hypocenterregion. Low b-value and high-Vp in the region isobserved towards the north-east and north-west ofthe main shock which might be an indication of theexistence of relatively competent rock masses withthe fractured, overpressure gas-bearing formationand excludes the presence of the molten rocks.


16 22 - 24 January, 2011

S3_I1

Seismic Hazard Assessment for Karachi,Pakistan1MonaLisa (E-mail: [email protected]) and2M. Qasim Jan (1Department of Earth Sciences,Quaid-i-Azam University, Islamabad, Pakistan.2National Centre of Excellence in Geology,University of Peshawar, Peshawar, Pakistan.)

National Centre of Excellence in Geology, Universityof Peshawar, Peshawar, Pakistan

Seismic Hazard Assessment (SHA) for the site ofKarachi, using deterministic approach, has beencarried out. Additional information in the form ofearthquake catalogue, delineation of active faults

within 50 km of Karachi, their relationship to theseismicity and focal mechanisms and theestablishment of seismotectonics zones have beenundertaken.

Due to the incomplete and short history of bothdocumented and instrumental earthquake distribution,no clear pattern of seismicity has been observed. Adistinct clustering of events, however, has been notedin the west of Karachi, in the Makran subductionzone. Majority of the earthquakes range in magnitudefrom Mw 4.0 to 5.0, but the 1945 Makran earthquakethat occurred about 250 km west of Karachimeasured Mw 8.1. Prominent seismic activity isconcentrated in the north and NW of the Karachicity.

S3: Seismicity and Earthquake ParametersConveners : J. R. Kayal and Prantik Mandal

THEMEThe essence of seismology lies in the observation and interpretation of earthquakes interms of seismicity, seismological characteristics, source parameters and the sourceprocesses. There is a continuing need to improve knowledge on the intra-plate as well ason the inter-plate seismicity. The information that are extracted from seismograms need tobe reviewed and expanded so as to provide the best possible analysis and interpretation.Thus methods for seismological interpretation need to make an account of the Earthcomplexities, development of seismic modeling and intensive computation that has benefitedgreatly from advances in computer technology. Most earthquakes in continental areasrequire an understanding of the distribution of seismicity and faults beyond; how thestructural and tectonic setting condition earthquakes of various kinds of geologic,geophysical and seismologic phenomena.

Contributions are invited for all aspects of the collection, analysis and interpretation ofseismological data in intra-plate and inter-plate seismic environments including:

1. Developments in seismic networks and data centers-including land, ocean-bottomand planetary networks, international data exchange, management of massive datasets.

2. Comprehensive seismogram analysis at single stations, seismic networks and arrays,potentials and future developments.

3. Rapid and routine determination of earthquake parameters including location andsource parameters, fault-plane solutions, seismic characteristics like b-value, p-value, fractal dimension etc.

4. Advances in wave propagation in heterogeneous media, including syntheticseismograms and waveform modeling in realistic Earth structures, theory andobservations of scattering, attenuation and anisotropy.

5. Developments in seismological interpretation, including development of inversiontechniques and seismic tomography.

1722 - 24 January, 2011


Delineation of active faults through geological fieldstudies and focal mechanism studies (Mw ³ 4earthquakes) indicate three active seismotectnicszones around Karachi. These are: Zone 1 in thesouth of Karachi, with transtensional featurescomprising strike-slip and normal faults, Zone 2 inthe north of Karachi, with pure strike-slip faultssystem, and Zone 3 with blind thrusts in the east andwest of Karachi. The b-value and maximum potentialmagnitude have been assigned to these zones. SHAincorporating deterministic approach has beenundertaken using two attenuation relationshipsadopted for Iran and India. The SHA shows highervalues for the zone 2 (0.3 g) and 3 (0.32 g). Theseismic design parameters, i.e. Operational BasisEarthquake and Maximum Credible Earthquakeaccelerations, have also been determined.

S3_I2

An Overview of the Seismic Activity andAssociated Hazards in South-America and theCaribbean: Socio-Economic Impact of SevereEarthquakes in These Regions

Omar J. Pérez(E-mail: [email protected]),Carlos Rodríguez and José L. Alonso (SimonBolivar University, Dpt. Earth Sciences, Caracas,Venezuela.)

Most of the population of western South-Americanand the Caribbean countries are selectivelyconcentrated along seismic belts that have been thelocus of frequent destructive earthquakes in historicaland recent times, occasionally accompanied bytsunamis, great landslides and other earthquake-induced natural phenomena. The ~70 mm/a to ~80mm/a east-northeast subduction of the Nazca platebeneath the South-American continent has resultedin several of the largest earthquakes with acumulative death toll exceeding 100,000, hundredsof thousands of people injured and homeless, billionsof US dollars in economic losses, and rathercommonly wide-spread damage, impacting big citiesand towns, industries, public buildings, the educationaland health sectors, electrical and power lifelines,commerce and infrastructures of communications,the most recent disaster being that generated by thegiant (Mw 8.8) Chilean quake of February 2010.The Caribbean plate, slipping easterly at a rate of~20 mm/a relative to North- and South-America,

shows a relatively low seismic productivity with plateboundaries characterized by the occurrence ofrelatively small (Mw < 8) seismic events. Yet it hasgenerated several lethal earthquakes in historical andrecent times, including the 1812 Venezuelan quakeduring which 8% of the country’s population waskilled, and more recently the Haiti event of January2010 that resulted in an estimated death toll of around250.000 people and a country practically destroyedby a fairly small (Mw 7.0) seismic event. Most ofthe population in South-America and the Caribbeanis urban, with belts of misery and povertycharacterized by poor constructions and facilitiessurrounding the rich portions of large cities andtowns. This increases dramatically the seismicvulnerability of the population and clearly indicatesthe need of research not only in seismology, tectonics,earthquake engineering and other branches ofscience including social and economical sciences,but also the need to define and implement responsiblePolicies of State in each country, including an inter-American system of mutual assistance, designed tomitigate the effects of earthquakes and other naturaldisasters in society.

S3_C1

A study of Source Parameters, SiteAmplification Functions and AttenuationParameter from the Accelerograms of anEarthquake in Delhi Region

Manisha, Dinesh Kumar and S.S. Teotia(Department of Geophysics, Kurukshetra UniversityKurukshetra 136 119 India.)

The Delhi region lies in the geological realm of thePeninsular India (PI) and is about 200 km away fromthe Himalayan collision zone. However, a great orlarge earthquake in the Central Seismic Gap (CSG)of Himalaya may cause severe damages in the Delhiregion. Further, it has been suggested that within Delhiregion, there is a deficit in released seismic strainenergy, capable of generating a damaging earthquake(Verma et. al.(1995), J. of Himalayan Geology). Theoccurrence of such an event in a densely populatedcity with several old and weak structures such asDelhi can be devastating. The locally recordedaccelerograms carry rich information about thesource parameters, which may be used for testingmodels of sources, which in turn may be used forthe evaluation of seismic hazard in the region. Such


18 22 - 24 January, 2011

data set is, however, limited in the Delhi region. Theaccelerograms of the 25th Nov., 2007 earthquakeoccurred in Delhi (28.6°N, 77.0°E, depth 20 km,magnitude 4.7) recorded at nine sites provide anopportunity to do the source analysis. Theseaccelerograms have been used to estimate the sourceparameters, site amplification and attenuationparameter. The SH waves are minimally affectedby the crustal heterogeneities and correction formode conversion at the free surface is not required.The source spectra obtained from the accelerogramshave been modeled in the terms of Brune Spectra toestimate source parameters (moment, magnitude,stress drop, source dimension) and attenuationparameter Q. The site amplification characteristicshave been estimated using the ratios of horizontaland vertical component spectra at various sites. Thefrequency bands where there was a significantamplification were identified. These amplificationbands are related to the ones where a departure ofthe observed source spectral data from the best-fitBrune source model is observed. We note asignificant site amplification (3-4 times) at the siteof Maharaja Aggarsain College (MAC) situated onyounger alluvium in the trans Yamuna region. Forthe sites situated in older alluvium (like Guargaon,Rewari, Ballabhgarh) the site amplification levels arelower than MAC.

S3_C2

Source Parameters and Scaling Relations forSmall Earthquakes in Kumaon Himalaya

K. Sivaram and S.S. Rai (National GeophysicalResearch Institute, Hyderabad India);Dinesh Kumar (E-mail:[email protected])and S.S. Teotia (Department of Geophysics,Kurukshetra University Kurukshetra 136 119India.)

The interdependence of various earthquake sourceparameters like magnitude, moment, fault dimension,stress drop, corner frequency, seismic energy aretermed as scaling relations. These scaling relationsare required to understand the physics of earthquakesand fault dynamics in a region. These relations alsoprovide the sound basis for estimating the seismichazard potential in a region. The simulation ofearthquake ground motions is required for the properevaluation of seismic hazard in a region. Theamplitudes of simulated time histories are governed

by the values of source parameters like stress dropand fault dimensions in addition to other parameters.The scaling relations provide the estimates of theseparameters. The use of global scaling relations maynot be useful in some regions as the ambient stressconditions and ranges of stress drop may differ fromregion to region. Therefore the regional scaling lawsare required to determine the values of stress dropand fault dimensions.

The purpose of the present study is to estimate sourceparameters and to develop the scaling relations forsmall earthquakes in the region of KumaonHimalaya. The study is based on the spectral analysisof 30 earthquakes with magnitude range 3.4 – 4.6recorded at broad band instruments in the region.The displacement spectra of P- and S-waves havebeen analyzed with Brune’s ω-2 model. A two stepsearch procedure for determining the optimum valuesof the parameters is used while estimating the cornerfrequency using Andrews approach. A misfit functionbetween the fitted Brune spectra and observedspectra has been used in the procedure. The averageratio of the seismic moment from S to P wave isfound to be 1.04. The agreement between theseismic moments estimated from P and S wavesshows that the results obtained are reliable. A shiftin the corner frequency estimated from P-wave andS-wave has been observed. The scaling relationbetween seismic moment and stress drop suggestsdecreasing stress drop with decreasing seismicmoment. The results of the present study areexpected to be useful for the proper evaluation ofseismic hazard in the region.

S3_C3

Spatial statistics: A Technique to constrainEarthquake Cluster to Prognosticate PotentialSeismic source zones

Basab Mukhopadhyay(E-mail: [email protected]),Sujit Dasgupta (Deputy Director General (Retd.),Anshuman Acharyya and A. K. Malaviya(Geological Survey of India, 27 J. L. Nehru Road,Kolkata – 700016, India)

One of the key issues in seismic hazard assessmentis to identify earthquake source zones in a sociallyuseful platform with reasonably acceptable spatialattributes, particularly in regions of diffused seismicity

1922 - 24 January, 2011


like those in the Himalayas. Innumerable moderatesize earthquakes pop-up all along the length andbreadth of the Himalaya along with some damaginglarge and great earthquakes interspersed both inspace and time. From this apparent chaotic spatio-temporal distribution of earthquakes can we bringout some semblance to tag them as segments forstrain concentration and subsequent release asearthquakes? And can we then short-list them as‘past’ is the key to the ‘future’? Implicitly we arevouching for a characteristic earthquake sourcemodel but that is what crops out from our study.

Identification of earthquake source zones is one ofthe prime research areas for the earth-scientists andcan be approached through different disciplinesincluding geology, seismology, geodesy and statistics.Our discourse is on tackling the issue wherein a simplespatial statistical procedure has been attemptedthrough which the spatial extents of visually identifiedclusters of ‘epicentral plot’ can further be constrained.The procedure is a combination of two spatialstatistical techniques; near- and point densityanalysis. Point density is a statistical tool used toidentify areas where data points are concentratedmore or vice versa. To calculate point density, thedistance between the adjacent earthquakes ismeasured by near analysis and statistically a meandistance is calculated. This radius is used as searchradius to calculate area of the circularneighbourhood. Point density is derived as the totalnumber of earthquakes that locate within the circledivided by the area of the neighbourhood. A factorresulting from the size of earthquake is also takeninto consideration for deriving the point density value,e.g., 5 points are counted instead of one count foran earthquake of magnitude 5 in the selectedneighbourhood. This is done to offer more weight tolarger earthquakes. The measurement is then carriedout in an overlapping grid pattern both along latitudeand longitude of the map area by a sliding distanceequivalent to the search radius and calculated valuestored at the center of the circle. The resulting gridvalue has a mean (m) and standard deviation (sd).Areas with higher point density [value > (m + 1sd)]are marked as zones of spatial clusters.

Result of this statistical exercise has recently beenpublished (Mukhopadhyay et al., 2010) where 22spatial seismicity clusters have been demonstratedfrom the entire Himalaya and adjacent areas utilizing

data from 1964 to 2006. Additionally the sameearthquake catalogue was subjected to temporalanalysis through time-distance window technique tobring out 53 temporal clusters consisting of foreshock-mainshock-aftershock (FMA), foreshock-mainshock(FM) or mainshock-aftershock (FA) sequence.Curiously enough, these 53 temporal clusters locatewithin the 22 spatial clusters but at the same timeeach of these spatial clusters contains more stand-alone events than the temporal cluster events.

Proceeding further as detailed in our recentpublication, eight such spatial clusters (A to H: fromKashmir in the west to eastern syntaxis in the east)located within the Lesser Himalaya involving eitheror both MBT and MCT were short-listed for detailedseismotectonic and seismic hazard studies. Assumingthe length of these clusters as possible maximumrupture length, maximum capable magnitudes, Mwvarying from 7.7 to 8.4 have been projected.Inducting into the analysis of historical earthquakerecords, recurrence pattern and other seismo-geological attributes it has been prognosticated thatKangra (cluster B), East Nepal (clusters E & F),Garhwal (cluster C) and Kumaun-West Nepal(cluster D), in decreasing order of earthquake threat,are potential source zones for large earthquakes (≥Mw 7.7).

As a follow up to the above study which was basedon earthquake data up to June 2006 we present twoadd-ons in this paper. Within the area of study duringthe period July 2006 to May 2010, a total of 49teleseismic events of magnitude mb ≥ 5.0 arerecorded by NEIC out of which four are larger withmb ≥ 6.0. 42 earthquakes out of 49 events (85.71%)locate within 12 of the 22 spatial clusters; and out ofthese 12 clusters, six are among the eight for whichdetail study have already been presented. Thedamaging Bhutan earthquake of September 2009locates within the Bhutan- Bomdila (G) cluster. Theother three events locate within spatial clusters insouthern Tibet. This significantly adds to thecredibility of the mapped spatial clusters.

As further refinement, we have probed the datasetthrough extreme value statistics [Gumbel probabilityplot], with earthquake data from 1960 to 2010 forsome of the clusters. The study is still in progressbut preliminary analysis indicates that the expectedMmax for a return period of 50 and 100 years with


20 22 - 24 January, 2011

the following results: Kangra cluster (5.7 & 6.0);Garhwal cluster (6.4 & 6.8); Kumaun-West Nepalcluster (6.4 & 6.6); East Nepal clusters: Cluster E(6.4 & 6.8) & Cluster F (6.1 & 6.5); and Bomdilacluster (6.0 & 6.2). These probabilistic estimatesbased purely on statistics underestimates theearthquake magnitudes derived on the basis ofrupture lengths.

References:

Mukhopadhyay Basab, Acharyya Anshumanand Dasgupta Sujit, (2010), Potential sourcezones for Himalayan earthquakes: constraintsfrom spatial–temporal clusters. NaturalHazards, DOI 10.1007/s11069-010-9618-2,published online 26th September 2010.

S3_C4

Estimation of Seismic Source Parameters inNortheast (NE) India from body wave spectra

Alok Kumar Mohapatra(E-mail: [email protected]) andWilliam Kumar Mohanty (Department ofGeology and Geophysics, Indian Institute ofTechnology, Kharagpur, 721302.)

Source parameters are estimated for ten localearthquakes (M 3.8-4.9) recorded by a three-stationbroadband network during April 2001 - November2002 in Northeast (NE) India. The sourceparameters like seismic moment (M0), stress drop(Φ), source radius (r), radiant energy (Wo), and straindrop (Σ) are estimated using displacement amplitudespectrum of body wave using Brune’s model. Theamplitude spectra of transverse component of theS-waves are corrected for instrument response, pathpropagation effects (attenuation correction) andeffects of the radiation pattern. The estimatedseismic moments (M0), range from 5.98×1020 to3.88×1023 dyne-cm. The source radii (r) are confinedbetween 152 to and 1750 meter, the stress drop (Δσ)ranges between 0.0003×103 bar to and 1.04×103

bar, the average radiant energy is 82.57×1018 ergsand the strain drop for the earthquake ranges from0.00602×10-9 to 2.48×10-9 respectively. The estimatedstress drop values for NE India depicts scatterednature of the larger seismic moment value whereas,they show a more systematic nature for smallerseismic moment values. The estimated sourceparameters are in agreement with previous works.

S3_C5

Analysis of The Seismic Activity of El AsnamRegion

F.Bellalem, M.Mobarki and A. Talbi(Seismological Dept.Survey. CRAAG. BP 63Bouzareah.16340 Algiers-Algeria, Email:[email protected], [email protected])

The scope of this study is to analyze the seismicactivity of El Asnam Region between 1980 and 2009.The regional seismicity analysis is based on reliablecompilation of earthquake catalogs obtained fromdifferent agencies. All intensities and magnitudeswere converted to Ms Magnitude using appropriaterelationships. Dependent events were removed usingadapted time and space windows. In addition, thecompleteness of the catalogue as a function ofmagnitude was determined from the standarddeviation of occurrence rate plots, using theStepp(1972) methodology. The remaining 320independent earthquakes with Ms e” 2.8 wereused to obtain various parameters (b-value, z-value) to characterize the temporal and spatialseismic activity for El Asnam region . Finally, theobtained results are discussed to explain parametersvariability.

S3_C6

Stress Pattern in the Kangra-Chamba regionof Northwest Himalaya from Focal MechanismSolution.

Dilip Kr Yadav (Email:[email protected]),Naresh Kumar and Chandan Bora. (WadiaInstitute of Himalayan Geology, Dehradun-248001,India)

The Kangra-Chamba region of northwest Himalayais seismically very active. The microseismicityrecorded by a network of 36 stations for a period ofabout 5 years (January 2004 - March 2009) showsthat the activity is concentrated to the north of MainBoundary Thrust (MBT), in the Panjal Thrust (PT)and in the Chamba Nappe area. The maximumactivity is confined down to 40 km depth. 47 faultplane solutions (FPS) of earthquakes, magnitudes2.5<M<5.0, are used to for stress inversion. TheFPS at shallower depth (<10 km) showspredominantly thrust to strike-slip with a NE-SWdirected compression, and at deeper depth (10 – 40

2122 - 24 January, 2011


km) it shows normal faulting with small strike-slipcomponent with a SW-NE directed extension. Thelow angle dipping inferred nodal plane of theshallower earthquakes is compatible with the underthrusting Indian plate. The FPS at the deeper depth,on the other hand, are interpreted with the localseismogenic faults. The stress tensor inversionresults obtained from the FPS for the shallowerevents (depth <10 km) show that the maximumcompressional stress (ó1) trends at 29º and plunges6º degree, and the minimum stress axis (ó3) trendsat 134º and plunges at 67º . Below 10 km thecompressional stress (ó1) trends at 244º and plungesat 59º with tensional stress (ó3) trending at 9º withplunge of 20º.

S3_C7

Estimation of Earthquake Source Parametersand Site Response fromGeneralized Inversionof Strong Motion Network Data in KachchhSeismic Zone, Gujarat, India

Prantik Mandal (National Geophysical ResearchInstitute (CSIR), Hyderabad, India.);Utpal Dutta (University of Alaska Anchorage,Anchorage, AK, United States.)

Inversion of horizontal components of S-wavespectral data in the frequency range 0.1-10.0 Hzhas been carried out to estimate simultaneously thesource spectra of 38 aftershocks (Mw 2.93-5.32)of the 2001 Bhuj earthquake (Mw 7.7) and siteresponse at 18 strong motion sites in the KachchhSeismic Zone, Gujarat, India. The spatial variationof site response (SR) in the region has been studiedby averaging the SR values obtained from theinversion in two frequency bands; 0.2–1.8 Hz and3.0–7.0 Hz, respectively. In 0.2-1.8 Hz frequencyband, the high SR values are observed in the southernpart of the Kachchh Mainland Fault that had sufferedextensively during the 2001 Bhuj Earthquake.However, for 3.0-7.0 Hz band, the area of Jurassicand Quaternary Formations show predominantly highSR. It is apparent that in both 0.2–1.8 and 3–7 Hzfrequency bands, the presence of geological contactsand sediment thicknesses controls the site responsesin the Kachchh seismic zone. It is also inferred thatlarger site response (>1:2) values in the 0.2–1.0 Hz

frequency band could be indicating the probablepresence of soil class C (360 < Vs d” 760 m=sec)and D (180 < Vs d” 360 m=sec) in the Kachchhbasin (according to 1997 National EarthquakeHazards Reduction Program [NEHRP] provisions).The source spectral data obtained from the inversionwere used to estimate various source parametersnamely, the seismic moment, stress drop, cornerfrequency and radius of source rupture by using aniterative least squares inversion approach based onthe Marquardt-Levenberg algorithm. It has beenobserved that the seismic moment and radius ofrupture from 38 aftershocks vary between 3.1x1013

to 2.0x1017 N-m and 226 to 889 m, respectively. Thestress drop values from these aftershocks are foundto vary from 0.11 to 7.44 MPa. A significant scatterof stress drop values has been noticed in case oflarger aftershocks while for smaller magnitudeevents, it varies proportionally with the seismicmoment. The regression analysis between seismicmoment and radius of rupture indicates a break inlinear scaling around 1015.3 N-m. The seismic momentof these aftershocks found to be proportional to thecorner frequency, which is consistent for earthquakeswith such short rupture length.

S3_C8

Earthquake Interevent Time ClusteringInferred from Mixed Models

Talbi A. (E-mail: [email protected];[email protected]), M. Hamdache and M.Mobarki (Centre de Recherche en AstronomieAstrophysique et Géophysique CRAAGDépartement Etude et Surveillance Sismique.BP.63 Bouzareah 16340, Algiers. Algeria)

A simple mixed model is presented and fitted toearthquake interevent time distribution. The modeluses power law and Weibull distributions at shortand long interevent time ranges respectively. Thecorresponding proportions of dependent andbackground seismicity components are estimatedbased on the deviation between the empirical datadistribution and our model. The proposed model isdiscussed and its parameters inferred to objectivelyseparate the two seismicity components.


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Subsequently, the seismicity catalog can bedeclustered without the subjective consideration ofspace time windowing. The procedure uses acorrelation distance which is defined as a measureof clustering degree. Specifically, given a pair ofevents with interevent time τ, the probability that τseparate a correlated (clustered) pair is quantifiedusing the deviation between τ and the meaninterevent time τ . The simplest interpolation ofthe obtained percentage of clustered pair of events,suggest a V-shaped interpolation using two lineartendencies at short and long interevent times. Theresults show that a potential measure of theproportion of main events in the whole catalog‘background fraction’ can be obtained using theprobability that interevent times deviate significantlyfrom their mean. In this perspective, moreinterevent times deviate from their mean, more thecorresponding events tend to be clustered. Thesefindings are intended to help the construction of anobjective stochastic declustering algorithm.

Keywords. Interevent times, Mixed model,Declustering, Background seismicity

S3_C19

Triggering is fine but what causes earthquakesin Koyna-Warna region?

V.K. Gahalaut and Kalpna Gahalaut(National Geophysical Research Institute, UppalRoad, Hyderabad 500 007)

The Koyna-Warna region of relatively stablepeninsular India is a unique site in the world wherethe seismicity that reportedly began soon after theimpoundment of the Koyna reservoir in 1961 hascontinued for over 40 years. The main Koynaearthquake of December 10, 1967 (M 6.3) thelargest earthquake near a reservoir, ever recordedglobally, and the ongoing earthquake occurrencesin the Koyna-Warna region have been consideredas the reservoir triggered earthquakes. Ourknowledge about the seismicity of the region priorto 1962 is very limited due to the absence of seismicstations in the area. Since 1963, more than 100,000earthquakes, including about 200 of M>4, about 20of M>5, have been reported from the Koyna-

Warna region and frequency of the earthquakes ofpast 40 years is almost steady. All these earthquakesare considered to be triggered by the Koyna andWarna reservoir operations. Simulations of stressesand pore pressure due to the reservoir operation,visual inspection and statistical analyses of datasupport this view; however, what causes theseearthquakes is still an enigma. The triggeringmechanism requires that the faults should becritically stressed so that earthquakes with senseof motion commensurable with ambient stressdirection may be triggered on those faults. Thiscondition raises questions on the occurrence ofearthquakes with normal motion in the Warna regionin a predominantly compressive environment of thepeninsular India. We propose that there are at leasttwo predominant mechanisms operating in the regionwhich may be responsible for such and all otherearthquakes in the Koyna Warna region. We suggestthat the sustained high seismicity in this region maybe influenced by the geometry of the fault zonesand their interactions through stress transfer. Thesedistinct fault zones, inferred from the earthquakedistribution and their focal mechanisms, arefavourably oriented to each other in such a waythat earthquake occurrences in one of the faultzones increase static stress on the other, facilitatingfrequent and continuing occurrence of earthquakesin the region. Stress triggering appears to be animportant cause for continuing high seismicity as itbrings some of the stabilized faults closer to failurein the manner consistent with the inferred sense ofmotion. Another important mechanism which seemsto operate in the region is the effects of elastic plateflexure. The height of the Western Ghat escarpmentis usually considered to be maintained by flexure inthe east–west direction. Intense erosion andsediment loading further control its evolution. Wepropose that this promotes failure at shallow depthby a reduction of the normal stress on escarpment-parallel sub-vertical planes in the region. We suggestthat there could be some additional mechanismscontrolled by the subsurface structures which maylead to continuous and renewable strainaccumulation. Probably an accurate and densesubsurface imaging and crustal deformationmonitoring may help in further exploring this aspect.

2322 - 24 January, 2011


S3_C10

Source characteristics of Delhi earthquake(ML: 4.3) of 25th Nov., 2007

Rajesh Prakash, A. K. Shukla and R. K. Singh(India Meteorological Department, New Delhi)

The Delhi Sargodha Ridge (DSR) which traversethrough NCT Delhi forms an important tectonicelement in seismic hazard assessment of this region.The past study based on seismicity data generatedby seismic telemetry network of Delhi region showsthat the DSR is active and dominant mechanism innucleation of seismicity is thrust with minor strikeslip. Recently, a moderate magnitude earthquake(ML: 4.3) with epicenter at 28.5490N / 77.1090Eoccurred in Delhi (about 21Km south west of DelhiUniversity) on 25th Nov. 2007, was widely felt inDelhi and its adjoining areas. The fault plane solutionusing P-wave polarity data of Delhi seismic telemetrynetwork shows a thrust with a minor strike slipcomponent. The strike of one of the nodal planedipping southerly conforms to the trend of DSR. Theintensity map of this earthquake shows meisoseismalarea elongated elliptically along NW-SE direction inthe vicinity of DSR, which also implies that the sourceof this earthquake is due to the reactivation oftectonic activity along this. Another past earthquake(ML: 3.8) of date 28 April 2001, with epicenter inNCT Delhi exhibits fault plane solution in conformityto the trend of DSR

S3_P1

Waveform inversion of local earthquakes usingbroadband data of Koyna - Warna region,western India

D. Shashidhar (E-mail:[email protected]);N. Purnachandra Rao, D. Srinagesh, H.V.S.Satyanarayana and Harsh Gupta (NationalGeophysical Research Institute, Uppal Road,Hyderabad 500007, India.)

The Koyna-Warna region in western India is the bestexample of reservoir triggered seismicity. Theworld’s largest triggered earthquake of magnitude6.3 occurred on 10 December 1967 at Koyna,followed by several moderate to small earthquakesever since. Recent seismicity studies based on

deployment of a digital seismic network of 11 stationsduring August 2005 to December 2009 have indicateda concentration of seismicity towards south in theWarna region including a new zone of seismic activityto the south-west. Also, during the observation period,18 earthquakes of magnitude 4 and larger haveoccurred out of which 16 occurred near the Warnaregion while only 2 occurred in Koyna. In the presentstudy we model broadband waveform data of aboveearthquakes using waveform inversion approach.Several velocity models were tested to select thebest one based on the criterion of maximumwaveform match between observed and syntheticseismograms. In general, focal mechanisms ofnormal type with NS to NNW-SSE oriented faultplanes are obtained for the Warna events which arecorrelated with probable faults indicated byLANDSAT images and aeromagnetic anomalies.Focal depths of the earthquakes in the Koyna-Warnaregion have been precisely determined based on thesensitivity of whole waveform inversion at localdistances. The focal depths obtained near the Warnaregion are consistently in the range of 4-6 km, whiletwo earthquakes near Koyna have focal depths of 8and 9 km respectively. Joint modeling of hypocentrallocations and velocity structure has provided avelocity model that produced lowest travel timeresiduals.

S3_P2

Remotely Triggered Seismicity due to the 2001Bhuj Earthquake

G. Surve (Dr. K. S. Krishnan GeomagneticResearch Laboratory (I.I.G), Leelapur Road,Chamanganj, Allahabad – 221505,E-mail:[email protected]);G. Mohan (Department of Earth Sciences, IndianInstitute of Technology Bombay, Powai,Mumbai – 400076.)

Evidence of remotely triggered seismicity at largedistances due to strong earthquakes has beenreported by several workers. We explore theevidence of one such episode of triggered seismicityin the Deccan volcanic province (DVP) of India,due to the Mw 7.7 Bhuj earthquake that occurredon 26th January 2001. The seismic network


24 22 - 24 January, 2011

established by IIT Bombay, around Dalvat, 50 kmnortheast of Nasik, in south central DVP inMaharashtra, about 500 km south east of Bhuj,recorded an abrupt increase in the local seismicityfollowing the devastating Bhuj earthquake. A swarmof about 55 microearthquakes, magnitude < 2.2, wererecorded at Dalvat in a span of a few hours to threedays immediately after the main Bhuj event. Thenetwork, which initially comprised of 4 short periodstations at the time of occurrence of Bhuj earthquakewas expanded to include a broadband (100s) station.The overall background seismicity for the area isquiet low as compared to the triggered seismicity,which contributed to nearly 70% of the total catalogof recorded events. Overall about 200microearthquakes with magnitudes (Ml) rangingfrom 1.5 to 3.5 were recorded within the networkduring 2000 – 2002. The triggered seismicityfollowing a NW-SE trend and confined to shallowdepth of < 2km within the basaltic cover, may havebeen triggered by the change in local stress fielddue to the Bhuj earthquake. The composite faultplane solution computed indicates strike-slipmechanism for the triggered events. Theseobservations are significant as it is the first instanceof triggered seismicity observed due to a large distantearthquake within the intrapale region.

S3_P3

Evidence for Transverse Tectonics in SikkimHimalaya from Seismicity and Source Parameterstudy

Pinki Hazarika (E-mail: [email protected]),M. Ravi Kumar, G. Srijayanthi, P. SolomonRaju, N. Purnachandra Rao and D. Srinagesh,National Geophysical Research Institute UppalRoad, Hyderabad – 500007

In the present study, over 700 local earthquakes inthe region of the Sikkim Himalaya have beenaccurately located and analyzed using P and S traveltimes from a network of 11 broadband seismicstations operated by the National GeophysicalResearch Institute, Hyderabad. Further refinementof the hypocentral parameters using the hypoDDrelocation program resulted in well constrainedhypocentral locations. 468 earthquakes having localmagnitude (Ml) greater than or equal to 2 were

used to determine source parameters like seismicmoment (M0), source radius (r), corner frequency(fc) and stress drop (Äó). The estimated seismicmoment ranges 1.9X1012 Nm to 3.1X1016 Nm withaverage value 2.1X1013 ± 0.5483 Nm, cornerfrequencies 1.25 Hz to 7.06 Hz while the averageis 2.62 ± 0.58, stress drop 0.56 bar to 131 bar withaverage 2.75 ± 10.4 bar and the source radius 0.2to 1.12 Km with average value 0.55 ± 0.16 Km.Interestingly, this study reveals severalcharacteristic features that distinguish Sikkim fromthe rest of the Himalaya. The seismicity distributionis found to be confined mostly between the mainboundary thrust (MBT) and the main central thrust(MCT) but not quite associated with either. Whilethe entire Himalayan front is generally characterizedby shallow-angle thrust faulting, focal mechanismsin this region are predominantly of strike-slip typein conformity with a right-lateral strike-slipmechanism along the northwest-trending Tista andGangtok lineaments. The P-axis trends ofearthquake focal mechanisms are clearly orientednorth-northwest, marking a clear transition from theambient north-northeast trending direction of Indianplate motion with respect to the Eurasian plate allalong the Himalayan front. Moderate-sizedearthquakes occur down to 70 km depth in thisregion, compared to an average focal depth of 15–20 km in the rest of the Himalaya. Also, a highaverage crustal P velocity of 6.66 km/sec and afairly low b value of 0.83 ± 0.04 are obtainedindicating the probability of occurrence of a highermagnitude earthquake in the future. Using leastsquare approach found the relation between thelogarithm of seismic moment (M0) and localmagnitude (Ml) as LogM0 = 0.64Ml + 11.67 andrelation between moment magnitude (Mw) and localmagnitude (Ml) as LogMw = 0.73Ml + 0.94 whichare little different from the standard relations. Anorth–south section in the Sikkim region shows arelatively flat topography, unlike in the rest of theHimalayan mountain chain and suggestive of lowerrates of convergence in the recent geologic past. Itis proposed that crustal shortening in the SikkimHimalaya has been substantially accommodated bytransverse tectonics rather than underthrusting inrecent times.

2522 - 24 January, 2011


S3_P4

Right Lateral Strike Slip Environment in KutchRift, Northwestern India: Moment TensorInversion Studies.

Ch. Nagabhushana Rao1, N. PurnachandraRao2 and B.K. Rastogi1 ( 1Institute ofSeismological Research, Raisan, Gandhinagar,Gujarat 382018, India. 2National GeophysicalResearch Institute (Council of Scientific andIndustrial Research), Hyderabad, 500007, India.)

The Kutch region in northwestern India, close to theIndia-Arabia and the India-Eurasia plate boundaries,is a paleo-rift that has experienced devastating intra-plate earthquakes in the past, namely the 1819 AllahBund earthquake (M 7.8), the 1956 Anjar earthquake(M 6.0) and the 2001 Bhuj earthquake (M 7.7).

Inversion of seismic waveform data of nineearthquakes in the magnitude range of 4 to 4.6 inthis region recorded by the Institute of SeismologicalResearch (ISR) during 2007-2009 yields reversefaulting and strike slip faulting solutions in the depthrange of 8.5 to 35 km. The inferred fault planescorrelate well with the local trends of the tectonicfaults, while the principal compressive stressdirection derived from stress inversion trendsagreeably with the ambient stress field direction ofNNE-SSW. It is inferred that in the Kutch region aright lateral strike slip environment prevails alongpredominantly NW-SE oriented deep-seated pre-existing faults in an otherwise reverse fault regimegoverned by the Indian plate collision with respectto the Eurasian landmass.


26 22 - 24 January, 2011

S4_Keynote-1

Luminescence Dating in Paleoseismologyand Neotectonics: An Overview

A.K. Singhvi1 (E-mail: [email protected]),R.N. Singh2 (E-mail: [email protected]) andM.K. Murari1*(E-mail: [email protected])1Physical Research Laboratory, Ahmedabad 380009, India. 2INSA Senior Scientist, NGRI,Hyderabad 500 00606, 1*Present Address:Department of Geology, University of Cincinnati,Cincinnati OH 45221. USA)

Luminescence dating relies on the use of naturalminerals as dosimeters of natural radiation fieldarising due to the decay of U, Th and K in the rocks/sediments, along with the cosmic rays. The methodenables the dating of the most recent heating (to∼400°C) or the most recent exposure a few seconds,to clear day light. This fact makes it possible to datea variety of seismic/tectonic events. These include,1) the dating of fault-gouge (heating during faulting),2) the dating of fault scarp (daylight exposure duringscarp formation), dating of sand dykes (thermalresetting during dyke formation), 3) dating ofseismeites (day light exposure of the sediment atthe sediment -water interface) and, 4) via the datingof sediments above and below the deformed strata.These open new possibilities in quantitativepaleoseismology.

Modeling efforts indicate that the even minor slipscan generate sufficient heat to thermally reset thegeological luminescence of the rocks in the faultzones, (Murari et al, 2009). In sand dykes, theobserved resetting of the luminescence has beenenigmatic but the modeling efforts indicate thermalresetting, during dyke injection at high velocities withassociated grain friction (Singh et al., 2009).

In this presentation, we shall outline som e of thebasic elements of luminescence dating in the contextof dating past seismic events and present some casestudies to elucidate the methodological aspects ofthe method in dating such events.

Flash heating of faults and resetting of TL clock inshallow earthquakes, M.K. Murari, R.N. Singh andA.K. Singhvi. Abstract O31, Second Asia PacificSeminar on Luminescence and ESR dating, Nov. 12-15, 2009, Physical Research Laboratory, Ahmedabad,380009, India, p. 81.

Flash Heating in Sand Dykes: A possible zeroingmechanism for OSL dating, R.N. Singh, M.K. Murariand A.K.Singhvi. Abstract O30, Second Asia PacificSeminar on Luminescence and ESR dating, Nov. 12-15, 2009, Physical Research Laboratory, Ahmedabad,380009, India, p. 109.

S4: Paleoseismology and Historical SeismologyConveners : Susan Hough, Roger Bilham and Javed N. Malik

THEMEHistorical earthquake studies, which typically involve development of modern methodsto analyse macroseismic data from archival sources, can provide invaluable informationabout earthquake processes and earthquake hazard in Asia, which boasts both wealthyancient cultures and significant earthquake hazard. However, the historical catalogueof earthquakes is still substantially incomplete in several countries which are under thethreat of earthquake hazard. Paleoseismological studies, including traditional trenchingas well as other methods, provide a complimentary approach to identify and investigatethe historical and pre-historical earthquakes signature preserved in the geological record.Such investigations have also been carried out in some countries, although many targetsremain to be explored to better quantify fault slip and earthquake rates. We invite papersthat present the results of historical and paleoseismological investigations of earthquakesand faults in Asia, including contributions that explore the implications of results forbasic questions involving fault and earthquake processes, and seismotectonics. We alsoinvite contributions that explore the implications of results for improvements in hazardassessment.

2722 - 24 January, 2011


S4_I1

Active Faults in Kachchh Region and Issue onthe Seismic Hazard Assessment

M. Morino (E-mail: [email protected]); J.N. Malik (E-mail: [email protected]); and F.Kaneko (E-mail: [email protected])

The 2001 Bhuj earthquake (Mw 7.6) was firstlyestimated to be generated by the Kachchh MainlandFault (KMF), due to the serious damages at Bachauand Bhuj Towns. However, the aftershock distributionrevealed it has been generated by a blind fault locatedon the north of the KMF. Our trench investigationacross the KMF and the Katrol Hill Fault (KHF),carried out as part of the “Seismic Microzonationof Gandhidham” project, confirmed they are activefor the first time.

The results showed that the KMF is a reversefault inclined to the south and the amount of the net-slip for a single seismic event is around 5m. TheKMF displaced all layers except top soil, inferring itmight rupture during historic age. For the KHF, thereis a branched fault which may cross beneath theBhuj Town. There are no historic documents on thepaleo-earthquakes along the KMF and KHF. Thismay suggest the possibility of their rupture in nearfuture with a long elapsed time since the lastearthquake. If the KMF and/or the KHF rupture innear future, Bachau, Bhuj, and Gandhidham mustsuffer severer damages than the 2001 earthquake.

S4_C1

Partitioning of convergence in Northwest SubHimalaya: indication from convergence and sliprates estimated across Kangra Reentrant,North India

V.C. Thakur (E-mail: [email protected]),D.Sahoo, Ajit Singh, N. Suresh, M. Joshi andR. Jayangondapermal (Wadia Institute ofHimalayan Geology, Dehradun-248001, India)

During Holocene, 21 mm/yr and 13 mm/yr north-south shortening on the Himalayan Frontal Thrustwas reported in the Central Nepal and the GarhwalSub Himalayas respectively. These rates wereinterpreted as representing the shorteningaccommodated on the Main Himalayan Thrust(MHT) decollement. In the Kangra reentrant ofHimachal Pradesh in northwest Sub Himalaya, thelong term shortening rate of 14 ± 1 mm/yr betweenthe Main Boundary Thrust and the Himalayan FrontalThrust has been estimated earlier based on balancedcross-section. On the short term, the GPSmeasurements have indicated 14 ± 2 mm/yrinterseismic slip on the MHT. Using uplifted strathterraces and fan surfaces on the hanging walls ofthrust faults, the uplift, convergence and slip ratesdue to faulting are computed. Shortening ratescalculated on the Jawalamukhi Thrust (JT) is 3.49mm/yr during 32 ka and 4.86 mm/yr during 17 ka.The Soan Thrust (ST) yields shortening and slip ratesof 2.98 mm/yr and 3.44 mm/yr respectively during29 ka. The shortening and slip rates on the HFT areestimated as 6.04+ 0.4 mm/yr and 6.98+ 0.5 mm/yrrespectively during 42 ka. These rates representconvergence accommodated along the MainHimalayan Thrust (MHT) by fault segments HFT-MHT, ST-MHT and JT-MHT during differentperiods of time. This may have implication forseismic hazard assessment in the Kangra reentrantwhich was affected by the 1905 Kangra earthquakeMw> 7.8.


28 22 - 24 January, 2011

Balanced cross-section across Kangra reentrantshowing shortening/ slip rates on thrust faultscomputed in our study. Long and short terms totalshortening/slip rates between the HFT and MBT(After Powers et al, 1998, Banerjee, P., Burgmann,R., 2002).

S4_C2

Paleoseismic investigations in the KopiliLineament Zone, Northeast India.

Devender Kumar (E-mail: [email protected]),D.V. Reddy and P.Nagabhushanam (NationalGeophysical Research Institute (Council ofScientific and Industrial Research), Uppal Road,Hyderabad – 500 007 (India))

Paleoseismological investigations are used toconstrain the historic/pre-historic earthquakesspecially that occurred during pre-instrumentalperiod. NE India is one of the active seismic zonesfrequented by large to great earthquakes in the recentand distant past. Being located between the meizo-seismal areas of the 1897 Great Assam earthquakeand the 1950 Upper Assam Earthquake, the KopiliLineament Zone (KLZ) has high potential for largeto great earthquake in future even though the stressis being released through several tremors of the orderof M 4.5, apart from the major earthquakes of 23rd

October 1943 (M 7.2) and the Cachar earthquakeof 1869 (M 7.5). The recently increased seismicityalong the Kopili lineament warrants the importanceof looking into the past seismic history of the area.The present paleo-seismic studies in this region mainlyconcentrate on locating, documenting andconstraining the timing of seismogenic liquefactionfeatures. The 14C and optically stimulatedluminescence (OSL) chronology of the organicmaterial and sediments associated with these featuresprovide a seismic history of approximately last 1000years. During this period, the region is inferred tohave experienced at least three major seismic eventsoccurring at (i) 1000 yr BP, (ii) between 400-800 yrBP, and the latest one (iii) between 200-360 yr BP.Missing are the age components which couldconstrain the October 23, 1943 earthquake, andfeeble evidence obtained for the 1869 Cacharearthquake.

S4_C3

Paleoseismology along an intraplate fault:Talas-Fergana, Tien-Shan mountains, centralAsia

Derek Rust (School of Earth and EnvironmentalSciences, University of Portsmouth, UK, E-mail:[email protected]),Andrey Korjenkov, Alexander Bobrovskii andErnes Mamyrov (Institute of Communication andInformation Technologies, Kyrgyz-Russian SlavicUniversity, Bishkek, Kyrgyzstan),

The Talas – Fergana fault bisects the Tien ShanMountains, the northernmost expression of Himalayandeformation, and displays classic features of recentactivity. Historical and instrumental records indicatethat no ground rupturing earthquakes have taken placein the last 250 years, despite many large earthquakesoccurring elsewhere in this actively deforming region,suggesting the Talas-Fergana may represent a seismicgap. Our field study has concentrated on three reachesof the fault zone that display multiple indicators ofrecent offset. In the first, radiocarbon dating oforganic-rich fill collected from one in a series of enechelon faulting-generated fissures gives an age of480+/-35 BP, while a dissected peat blanket on theupthrown side of a scarp interpreted to have beenproduced by the last faulting event yields dates of 405+/-100 BP and 460+/-40 BP. Farther southeast thesecond and third sites display perched channelsrecently abandoned by drainage, now entrenched inmore direct courses, which were previously deflectedalong the fault. The entrenched channels have bothbeen offset by similar amounts (55-60 and ~70 m) ofpost-entrenchment fault movement. Exploratory pitsdug in the perched channels provided samples for OSLand 14C dating and, although further dating resultsare awaited, suggest the entrenchment event tookplace 5-6 Ka ago, indicating a slip rate since of 10–15mm a-1. Dates from the upper part of one perchedchannel fill, and from a small terrace deposit upstreamon the related entrenched drainage, are respectively505+/-80 BP and 440+/-45 BP. The statisticallyindistinguishable recent 14C dates, which coincide witharchaeoseismic dating from a ruined Silk Roadcaravansary in the region, and with publishedlichonometry results from a nearby large and probablyseismically-triggered landslide deposit, suggest thatfaulting last occurred between 400 and 500 BP, andindicate a major event rupturing >100 km of the fault.

2922 - 24 January, 2011


The authors acknowledge the support of NATOScience for Peace, Project 983142

S4_C4

Active fault mapping using high resolutiongeophysical field investigation in Kachchh:Implication to Quaternary rejuvenation

A.K.Gupta (E-mail:[email protected]),Girish Ch. Kothyari, Rashmi Pradhan,Mukesh Chauhan,R. K. Dumka, R. K. Singhand B.K. Rastogi(Institute of SeismologicalResearch, Gandhinagar -382009, Gujarat, India)

The landscape of Kachchh has been shaped bymultiple step tectonic movements along various faults.These faults originated due to the break-up andnorthward drift of the Indian plate. In the northernmargin of Kachchh region significant features relatedto active deformation have been observed. On thebasis of field observations, it seems that the area isunder influence by NE-SW trending oblique sliptectonic movement with reverse component over theE-W major faults. Ground deformation has beenobserved in the fault zones as uplift and subsidenceof ground. The E-W compressive force in the regionhas resulted in the development of folding ofQuaternary sediments in Great Rann of Kachchh(GRK). Some micro-earthquake activities have alsobeen noticed along the NE-SW tectonic trend. Highresolution geophysical GPR survey with a 200 MHzreceiver has been conducted in the area to verifythe active deformation. A total of 1 km long N-SGPR records were collected across the IBF zone.2D GPR Image clearly indicates development ofmajor fracture at a depth of 6m, which may beformed due to compressional tectonic environment.These observed faulted features were validated andcross checked by conducting gravity survey usingCG-5 auto gravitymeter at 1 km station interval(approx.) for better understanding of deformationwithin NE-SW tectonic trend. The topographicfeature in the region, showing sudden changes inrelief, is reflected by low bouguer gravity. Steepgradient in Bouguer and free air gravity anomaliesbetween Amarapar and Lodrani reflects faultedbasement in the area. Towards the Balasar suddendrop in gravity seen in gravity profile and alsoreflected in the topography in the form of sudden

changes in gradient, this could be due to differentialuplift in IBF and NE-SW trending fault. Similarsituation has been observed in Chitrod - Balasarsection of Wagad region. The topographicalexpression in Chitrod region shows high reliefwhereas towards Balasar the gradient is decreasing.Negative gravity response in high relief areas mightbe due to rejuvenation and upliftment of sedimentarystructures.

S4_P1

Morphotectonic control on drainage networkevolution in the Upper Narmada Valley:Implication to Neotectonic

Girish Ch. Kothyari(E-mail: [email protected]); andB. K. Rastogi (Institute of Seismological Research,Raisan, Gandhinagar, 382 009, Gujarat India);

The intra-continental convergence of the Indian platetowards Eurasia is being reflected in the recurrentfault movement in the form of neotectonics.Neotectonic features have been observed usinggeomorphometric analysis of small catchments areaof upper Narmada basin using high resolution ASTERand SRTM-DEM data. Parameters like topographiccross-sections, longitudinal river profiles, streamlength gradient index (SL) and asymmetric factorwere studied to understand tectonic movement. Thestream length gradient index (SL) suggestsdifferential uplift along the Narmada valley. Suddenchanges in slope of Narmada river floor is seen asknick points along South Narmada Fault (SNF) andalong Jabalpur Fault. Drainage basin asymmetry ofupper Narmada basin has been used as a quantitativeparameter to understand tectonic deformation. Thecross topographic profile has been generated usingDEM data to understand the landscape evolutionpattern of upper Narmada basin. Various tectonicallyinduced geomorphic signatures have been identifiedusing satellite Google Image in the region such asfluvial incision in bedrocks, formation of gorges withvertical walls and shifting of river channel towardsNNW direction. All the above features indicateneotectonic activity.


30 22 - 24 January, 2011

S5_I1

Changing Scenario of Earthquake precursoryResearch

B. R. Arora (Wadia Institute of HimalayanGeology, 33 GMS Road, Dehradun 248 001, India.E-mail: [email protected]; Fax +91 135 2525200)

The space-time pattern in micro-seismicity, seismicswarms, seismic wave velocity change, ‘b’ value,RTL algorithm in a given seismic zone show promisein identifying precursors to impending earthquakes.Despite some success stories, pessimism prevailedas noted changes were not observed at allearthquake sites or even for different earthquakesin the same region. The lack of sound physicalhypothesis that could explain and validate precursorybehaviors further added to the skepticism. Thedilatancy-diffusion model based on behavior of rocksunder stresses in laboratory conditions has somesuccess not only in explaining the noted seismologicalprecursors but also suggested presence of small-scalechanges in gravity, resistivity, magnetic field intensity,electromagnetic and radon gas emission as well asfluctuations in hydrological parameters. Given thatthe numbers of parameters are expected to showcharacteristic space-time variation during theearthquake preparatory cycles, task force constituted

by Ministry of Earth Sciences, Govt of India hasrecommended simultaneous measurements of inter-disciplinary parameters. Given this realization, WadiaInstitute of Himalayan Geology (WIHG) hasestablished the first Indian Multi-ParameterGeophysical Observatory (MPGO) at Ghuttu, CentralHimalaya to study earthquake precursors inintegrated manner. Located in a narrow belt of highseismicity, just south of the Main Central Thrust ofthe Himalaya, has been the seat of recent 1991-Uttarkashi and 1999-Chamoli earthquakes, both M>6. The MPGO became fully operational in April 2007and is equipped with super conducting gravimeter,overhauser magnetometer, tri-axial fluxgatemagnetometer, ULF band search coil magnetometer,radon data logger, water level recorders and isbacked up by the dense network of Broad BandSeismometers (BBS) and GPS. The critical analysisof various geophysical time series indicates that thetime-variability of gravity field is influenced by soilmoisture and water table fluctuations, geomagneticfield changes are sensitive to solar-terrestrialdynamics, flux of radon emission is stronglydependent on environmental factors like temperatureand hydrology. These influences are the majordeterrent in the isolation of weak precursory signals.The presentation shall focus on the data adoptive

S5: Earthquake Precursors and Prediction StudiesConveners : B.R. Arora and R. K. Chadha

THEMERecognizing that earthquake precursory research hold key to earthquake prediction,search for precursors and their documentation has continued in different parts of theglobe. Accumulated evidences bring forth variety of precursory signals includingseismological, atmospheric/ionospheric, geodetic/geomagnetic, electrical resistivity/hydrological as well as geochemical anomalies. Despite certain definite success cases,skepticism prevails as noted changes are not observed at all earthquakes sites or evenfor different earthquakes in the same region. The dilatancy-diffusion model based onbehavior of rocks under stresses in laboratory conditions has some success in explainingsome of the noted precursory signals. Induction of con-current multi-sensor measurementsand availability of satellite data have begun to demonstrate the promising role of non-seismological parameters in earthquake forecasting programs. The present session shallreview the advances in earthquake precursory programs to devise road map for futureplanning and practical application of earthquake precursory research. Papers dealingwith any aspect of earthquake precursory research are welcome. Papers focusing onmodern mathematical tools to isolate precursory signature in real time, establishing theirspace-time relation to earthquake cycle and highlighting strategies for integrating multi-sensor data are especially invited.

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techniques to estimate and eliminate effects of solar-terrestrial, hydrological/environmental factors ondifferent geophysical time series. Some exampleswill be presented to demonstrate if effects ofenvironmental and hydrology are not recognized andcorrected, some anomalies will be falsely viewed asearthquake precursors. On the other extreme, someprecursory signals are masked by factors other thanstress-induced changes.

Choice of session: Earthquake precursor andPrediction of Earthquakes Status of paper: InvitedKey note talkFax: +91 135 2621252

S5_I2

Monitoring Well water level changes – Whatdid we learn from our experiences in India?

R K Chadha (National Geophysical ResearchInstitute, Hyderabad-500007Email: [email protected])

The human quest for predicting earthquakes in thelast few decades has led to several claims ofsuccessful predictions ranging from geophysical togeochemical precursors to abnormal animal behavior.Except for a few cases, most of these claims havebeen post earthquake occurrence. While some ofthe studies are based on well documentedmeasurements several of them are isolatedmeasurements based on single instrument leading tohigh uncertainties related to earthquake predictionresearch. Well water level changes associated withearthquakes is one of the precursors recognized bythe IASPEI sub-commission on earthquakeprediction.

In the Koyna region in Maharashtra, well waterlevels are being monitored since 1995 in 21 bore wellsdrilled around the seismically active region. Fourteenof the observation wells act as volume strain metersas their water levels show earth tidal signals. Theanalysis of more than a decade data show three typesof response of the well water levels to seismo-tectonic effects, i) one to local earthquakes, ii) toregional and teleseismic events, and iii) to localfluctuations in rock strain on regional scale. Fivecases of co-seismic step-like well water levelchanges, of the order of few centimeters in amplitude,related to earthquakes in the magnitude range

4.3d”Md”5.2 are observed. All these earthquakesoccurred within the network of wells drilled for thestudy and within 25 km distance of the recordingwells. In three cases, drop in well levels precededco-seismic step-like increases, which may be ofpremonitory nature. The second type of response isobserved to be due to the passing of seismic wavesfrom regional and teleseismic earthquakes like theM 7.7 Bhuj event on January 26, 2001 and the M9.3 December 26, 2004 Sumatra earthquake. Thethird type is a well level anomaly of centimeteramplitude coherently occurring in several wells. Theanomalies are similar in shape and last for severalhours to days. From our studies we conclude thatthe wells in the network appear to respond to regionalstrain variations and transient changes due to distantearthquakes. The two factors which are importantto co-seismic steps due to local earthquakes are themagnitude and epicentral distance. From the limitednumber of events we found that all local earthquakesexceeding Me”4.3 have produced co-seismicchanges. No such changes were observed forearthquakes below this magnitude threshold.

No simple model exists to connect pre- or co-seismicfluctuation of ground water levels. The sensitivityof deep wells to seismic activity is remarkably varied.In China, several successful earthquake relatedanomalies have been reported for earthquakesoccurring halfway round the world. This may be dueto the fact that these wells are very deep. Over 100research wells in excess of 1000 m deep have beendrilled solely for earthquake prediction purposes inChina. Similarly, in Japan and other countries wellwater levels are being monitoring in very deep borewells. In my presentation, results from Indianexperiment in Koyna and other worldwide cases willbe discussed.

S5_C1

Soil-gas Geochemistry for EarthquakeMonitoring and Fault Studies in Taiwan

Vivek Walia1*, T.F.Yang2 C-C. Fu2, S-J. Lin1,K. L. Wen1 and C-H Chen1 ( 1National Centerfor Research on Earthquake Engineering, NARL,Taipei-106, Taiwan,*Email:[email protected],[email protected]; 2Department ofGeosciences, National Taiwan University, Taipei-106, Taiwan )


32 22 - 24 January, 2011

The study of active faults and earthquake precursorysignals provides a basis for anticipating the futureearthquakes and related phenomena such as surfacefailure, faulting, and other geological/tectonic features.The Island of Taiwan is a product of the collisionbetween Philippine Sea plate and Eurasian platewhich makes it a region of high seismicity. In thesouthern part of the island the Eurasian plate issubducting under the Philippine Sea plate while inthe northern area of the island the Philippine Seaplate bounded by the Ryukyu trench is subductingbeneath the Eurasian plate. Behind the Ryukyutrench, the spreading Okinawa trough has developed.The northern part of Taiwan Island is located at thewestern extrapolation of the Okinawa trough.

The present study is proposed to investigategeochemical variations of soil-gas composition in thevicinity of the geological fault zones and to determinethe influence of such formations on the enhancedconcentrations of different gases in soil to monitorthe tectonic activity in the region. To carry out thepresent investigations, variations in temporal soil-gases compositions were measured at continuousearthquake monitoring stations established alongdifferent faults. Before selecting a monitoring site,the occurrence of deeper gas emanation wasinvestigated by the soil-gas surveys and followed bycontinuous monitoring of some selected sites withrespect to tectonic activity to check the sensitivityof the sites. From the results of long term geochemicalmonitoring at the established monitoring stations wecan divide the studied area in two different tectoniczones. We proposed tectonic based model forearthquake forecasting in Taiwan and tested it forsome big earthquakes occurred in recent past. Basedon the anomalous signatures from particularmonitoring stations we are in a state to identify thearea for impending earthquakes of magnitude e” 5and we have tested it for some earthquakes whichrocked the country in last six months. Most of theearthquakes having magnitude e” 5 with local intensitye” 2 at the monitoring stations, epicentral distance <100 kms with focal depth < 40 kms have shownprecursory signals and fitted very well according tothe proposed model.

S5_C2

Fractal Correlation Dimension Analysis toidentify precursory pattern prior to 15th July2009 New Zealand earthquake (Mw-7.8).

S.K. Mondal, R. Meena and and P. N. S. Roy(E-mail:[email protected],[email protected])(Department of AppliedGeophysics, Indian School of Mines, Dhanbad -826004, Jharkhand, INDIA;Phone : +91 326 2235469; FAX: +91 326 2296563)

New Zealand is located along a zone of contactbetween pacific and Australia plates. The motion ofthese plates leads to the major seismicity in thiscountry. The area of study with latitude 42 °S to 50°S and longitude 162 °E to 178 °E experiencefrequent intermediate earthquakes and also somestrong earthquakes. Seismically-active fault zonesare complex natural systems exhibiting scale-invariant or fractal deformation leading toearthquakes fractally distributed in space. Temporalvariations of spatial fractal (correlation) dimensionDc have been related to the preparation process fornatural earthquakes and rock fracture in thelaboratory experiment by the scientific community.We investigate the temporal variation of spatial Dcfor seismicity in the study area for earthquakes ofmagnitude > 3.9 occurring in the period between1973 to2009. The analysis of fractal correlationdimension of earthquakes provides some low Dcvalue before the mainshock. The three consecutivewindows of hundred events were observed to havelow value having mean time 3/3/2007, 12/9/2007 and22/2/2008.The mainshock was observed to haveoccurred after three low Dc windows. The low Dc(0.664) has been observed prior to main shock.These statistical scaling properties of seismicity maytherefore have the potential at least to be sensitivefor intermediate-term warning of major earthquakes.As the low Dc is an indicator of clustering and itshows how intermediate size events correlate witheach other. Hence low Dc value may be high stressindicator along the fault of the study region which isresponsible for strong earthquake, and one can sayabout the impending large earthquake. Thus thisstudy may be applied for well constrained catalogueof a region for assessing the hazard of that regionspatio-temporarily and which may be very usefulinformation for hazard mitigation.

3322 - 24 January, 2011


Key Words: Fractal Correlation Dimension,Seismicity and Clustering.

S5_C3

Investigations of anomalous signals prior tolarge earthquakes based on 1-Hzsuperconducting gravimeter records andbroadband seismometers data

WenBin Shen1,2, Dijin Wang1, CheinwayHwang3, Jun Yi1 ( 1Department of Geophysics,School of Geodesy and Geomatics, WuhanUniversity, China. E-mail wbshen@sgg,whu.edu.cn, 2 Key Laboratory of Geospace Environment andgeodesy, Wuhan University, China, 3Department ofCivil Engineering, National Chiao Tung University,Taiwan)

We investigate the anomalous signals prior toabout 30 large earthquakes (with seismic momentslarger than7.0) occurred in the period ranging from1 Jan. 2008 and 31 June 2010 using 1-Hz datarecorded by a superconducting gravimeter (SG)at Hsinchu station, Taiwan and by more than 10broadband seismometers (BSs) distributed overthe globe. We compute the power density spectra(PDS) of the records both in the non-seismicperiod and seismic period (the period just one orseveral days prior to large earthquakes), andcompare the non-seismic PDS with the seismicPDS to see whether there are anomalous signalsprior to large earthquakes. In another aspect, weapply Hilbert-Huang transformation (HHT)technique to the SG and BSs records to establishthe time-frequency-energy paradigms to examinewhether there are anomalous signals prior to largeearthquakes. Both the results of the PDScomparisons and the examinations of HHT time-frequency-energy paradigms suggest that beforemore than 50% large earthquakes there appearanomalous signals. Our investigations also suggestthat the anomalous signals prior to largeearthquakes may be related to the magnitude, focaldepth, fault orientation and distance between theobservation station and the epicenter. Furtherinvestigations in more details are still in progress.This study is supported by Natural ScienceFoundation China (Grant No. 40974015;40637034).

S5_C4

Changes Observed Prior and After the GujaratEarthquake of 26 January, 2001Using MultiSensor Satellite Data

Ramesh P. Singh1, 2 and Waseem Mehdi2

( 1School of Earth and Environmental Sciences,

Schmid College of Science, Chapman University,One University Drive, Orange, CA 92866, USA,2Research and Technology Development Centre,Sharda University, Greater Noida - 201 306, India)

Soon after the Gujarat earthquake (Ms – 7.6) of 26January, 2001, detailed analysis of multi sensorsatellite data (IRS P4 OCM, MSMR, MODIS, SSM/I, TOMS, MOPITT) together with meteorologicaldata have been carried out. Pronounced changes insurface, ocean, atmosphere and meteorologicalparameters have been observed prior and after theearthquake. The changes observed in surface,ocean, atmosphere, meteorological parameters showcomplementary behavior. Such complementarynature is also observed in total electron content. Thetotal ozone column observed from TOMS data showpronounced increase after the earthquake. All thesechanges show an evidence of the existence of astring coupling between Lithosphere-Atmosphere-Ionosphere and associated with Gujarat earthquake.A simple model will be presented that show that theobserved changes could be related to the earthquakeprocesses depending upon the subsurfaceconfiguration of the epicentral region.

S5_C5

Application of acoustic sounding in earthquakeprecursor detection: lessons from Bhuj, Indiaearthquake

H.N. Dutta (Email: [email protected]) and B.S.Gera (Roorkee Engineering & ManagementTechnology Institute, Shamli-247 774)

The death and destruction caused by the Bhuj, Indiaearthquake led to many scientific postmortems ofthe coincidentally available geophysical data. Onesuch observation was that of an acoustic sounderoperating at Vapi (Gujrat) in which an anomalousatmospheric gravity wave was recorded propagatingin the lowest part of the atmosphere on January 25,2001, a day prior to the occurrence of earthquake


34 22 - 24 January, 2011

on January 26, 2001. This wave was the firstsignature of a wave with an amplitude of about 480mand a wave period of 4 hours ever recorded in India/Antarctica in the past 30 years.

The investigators have been operating acousticsounders as part of the planetary boundary layerprogram to monitor the atmospheric thermalstructure right from surface up to a height of 1kmon continuous basis. On the basis of this singleobservation, the investigators have been able to takean international patent and have established thatacoustic sounders should be part of all earthquakeprecursor investigations, where, the couplingmechanism between geosphere-atmosphere-ionosphere coupling has to be understood. It may bepointed out that acoustic sounding offers a uniquephotographic display of all atmospheric processes inthe atmosphere, therefore, the impact of any escapeor leakage of energy, mass or momentum would beideally mapped / photographed in real terms, the onlypart that has to be emphasized at the moment is thatcouple of acoustic sounders must be deployed atsuitable sites in India or collocated with otherearthquake precursor monitoring techniques so thata firm conclusion is drawn and a branch of science,where India has taken a lead, the lead remainsmaintained.

The details shall be presented about the capabilityof the technology and its real time application inearthquake precursor technology.

S5_C6

Anomalous Changes in Groundwater and Soil-gas Radon concentrations in Relation toEarthquake Activities in Garhwal Himalaya,India: understanding this phenomenon as anearthquake precursor

R.C. Ramola(Department of Physics, H.N.B.Garhwal University, Badshahi Thaul Campus, TehriGarhwal-249199, India.),Sushil Kumar(Wadia Institute of HimalayaGeology, 33 GMS Road, P.B.No.74, Dehra Dun –248 001(UA), India,E-mail: [email protected],Phone: 0135-2525458, 09897220017)

During the last three decades, research onearthquake related radon monitoring has received

enormous attention. It has found to have a greatpotential as a reliable precursor for an impendingearthquake. This paper presents some results ofcontinuous monitoring of radon levels in soil-gas andspring water at Tehri (Garhwal Himalaya), India.Efforts have made to correlate the variation of radonconcentration in spring water with seismic events inthe study area. Sudden increases in radonconcentration in soil-gas and spring water wereobserved before, during and after the earthquakesoccurred in the area. The variations in radonconcentrations in soil-gas and spring water havefound to be correlated with the seismic activities inthe Garhwal Himalaya. The significant correlationbetween radon anomalies and earthquake activitiesin Garhwal Himalaya shows that this noble techniquemay be exploited as an additional tool in earthquakeprediction program in Himalayan region. To be usefulas a precursor in an earthquake prediction program,the continuous measurements of radon along withother precursors at several sites in a grid pattern isnecessary. The role and usefulness of radon in soil-gas and spring water as an earthquake precursorare discussed in this paper.

S5_C7

Anomalous variations of foF2 during Bhujearthquake of 26 January2001 and associationof GPS based total electron content withdifferent seismic events

O.P. Singh and Vishal Chauhan (Department ofPhysics, Faculty of Engineering & Technology,R.B.S. College,Bichpuri, Agra-283105, India);Birbal Singh(Department of Electronics &Communication Engineering, Faculty ofEngineering & Technology, R.B.S. College,Bichpuri, Agra-283105, India.)

The Bhuj earthquake of 26 January, 2001 (M=7.6)was the most severe earthquake in respect of widespread damage to life and property ever seen in Indiaduring the last 50 years. The effect of this earthquakeis examined on the nighttime (1800-0600 h LT)ionospheric parameter foF2 by employing the digitalionosonde data obtained from Ahmedabad(Geographic latitude, 23.010N, longitude, 72.360E).The percent deviation of foF2 from monthly medianfor pre-midnight (1800-0000 h LT) and post-midnight

3522 - 24 January, 2011


(0000-0600 h LT) sectors are examined critically.The results show that foF2 are reduced in both thetime sectors prior to the occurrence of main shock.The effects of magnetic storms in reducing the foF2are identified clearly and they do not vitiate the effectsof earthquakes.

To investigate the effect of earthquakes on theionosphere we have also carried out the GPS basedtotal electron content (TEC) observations at our Agrastation (Geographic latitude, 270N, longitude, 780E).For this purpose a dual frequency GPS receiver hasbeen in continuous operations since 24 June, 2006.Since then the morphological features of TEC datahave been studied and the TEC variations duringthe various seismic events also have been examined.It has been found in different cases that during thequiet geomagnetic conditions TEC data showperturbed behavior prior and after the occurrenceof earthquakes.

S5_C8

Signature of Seismo-Electromagnetic Signals(SES) in prediction of earthquakes

Vinod Kumar Kushwah(Email: [email protected]);M.S.Gaur (Email :[email protected]),R.K.Tiwari (Email: [email protected]); andRudraksh Tiwari (Email: [email protected])

Worldwide, medium – to short-term earthquakeprediction is becoming ever more essential for safeguarding man due to an un-abating populationincrease, but hitherto, there have no verifiable methodof reliable earthquake prediction developed-exceptfor a few examples of such in China and in Greece.The occurrence of earthquake is a globalphenomenon. Earthquakes occur due to movementsalong the faults that have evolved through geologicaland tectonic processes. These are most disastrousof all the natural calamities as they affect large areascausing death, injuries and destruction of physicalresources on a massive scale. No any country inthis time which escape the disaster of earthquake.We have analysed the data of HF to ULF (UltraLow Frequency) are found very interesting resultsto confirm the precursory nature of seismo-electromagnetic emission which are generated

before during and after the seismic activities. Now,we are trying to develop a new technique of detectionthe seismic singles by live sensors (i.e. Tree Bio-potential). This technique will play a very crucial rolein the field of prediction techniques. Firstly of all, weanalysed the data of tree bio-potential (off line) andtry to correlate the drastically change ofconcentration of internal contents (Xylem andphloem) due to generate of electromagneticemissions which produce the precursory nature ofseismic activities.

Keywords: Earthquake, ULF (Ultra Low frequency),Bio-potential, etc.,

S5_C9

Precursory Earthquake Studies inMaharashtra, especially in Koyna Region

Arun Bapat¹ and M.A.Ghatpande² (11/11, TaraResidency, 20/2, Kothrud, Pune- 411038, E-mail:[email protected], 2 Formerly from MERI,Nashik, E-mail: [email protected])

1. Introduction:

During last 400 years, there are three earthquakesof magnitude more than six in the State ofMaharashtra (1). The last two earthquakes, i.e.Koyna earthquake of Magnitude 6.5 on 11th

December 1967 and Killari (Latur) earthquake ofMagnitude 6.3 on 30th September 1993 weredevastating and have occurred within a span of 26years. The belief that Deccan Trap region ofMaharashtra is seismically stable was shattered bythe Koyna earthquake and confirmed by the Killariearthquake. After observing the seismic activity inthe Koyna region in 1961-62, the monitoring ofseismic activity in the State was initiated. At presentthere are about 53 seismological observatories inthe state of monitoring seismicity. Various NationalOrganizations like India Meteorological Department(IMD) New Delhi, National Geophysical ResearchInstitute (NGRI) Hyderabad, Geological Survey ofIndia (GSI) Nagpur, Indian Institute of Technology(IITB) Powai and Maharashtra EngineeringResearch Institute (MERI) Nashik are engaged inthis activity. The numbers of seismologicalobservatories by these organizations are asfollows:—


36 22 - 24 January, 2011

1) IMD : 72) NGRI : 7 to103) MERI : 354) IITB : 35) GSI : 1 Total : 53

MERI acts as a Nodal Agency appointed byGovernment of Maharashtra for earthquake studiesin the State. The seismic data from the observatoriesof different Institutes are analyzed and interpretedseparately. There is a need to combine all theavailable data for better evaluation and co-ordinationof observed results.

2. Seismicity of Maharashtra:

The Historical seismicity of Maharashtra reveals thatthe coastal Maharashtra has been seismically activesince historical period. Based on seismicity,Maharashtra can be divided into six regions. Theseare:—

Koyna-Warna Region (Dist.Satara): Seismically thisis the most active region in the State. Highestmagnitude recorded is 6.5 in Dec.1967.

Killari Region (Dist.Osmanabad & Latur): The areahas also seismic potential, but apparently theseismicity has died down considerably after thedevastating earthquake of magnitude 6.3 inSep.1993.

Bhatsa Region (Dist.Thane): The above area wasseismically active in 1983-84. At present, seismicityhas almost petered off. The highest recordedmagnitude happens to be 4.9 in Sep.1983.

Surya Region (Dist.Thane): The Surya area wasseismically active in 1994. At present the seismicityhas been almost died down. The highest recordedmagnitude in this region is 3.8. It was in Aug.1994.

Kalvan-Peth Region (Dist.Nashik): The spurt ofmicro-seismic activity has been recorded near Dalvatarea of Kalvan tashil and Kohar-Bhaigaon area ofPeth Tahsil .The maximum recorded magnitudeearthquake has been 3.3 in 1996.

Rest of Area : Spurt of Microseismic activity andindividual earthquake events have been recorded atRamtek (Nagpur), Nandurbar, Bhandara, Nanded,Bote(Ahmednagar), Dapoli (Ratnagiri),Yeotmal,

Wasim, Sironcha (Chandrapur), Palghar (Thane),Akole and Pune.

3. Precursory Earthquake Studies: —— AGlobal Scenario

Earthquake prediction has always been the subjectof challenge to the earthquake scientists the world-over. It is an old and elusive goal of seismologists. InIndia, Ballala Sena (10th-11th century A.D.) in his‘Adbhuta Sagara’ has written about causes ofearthquake. Varah Mihir (5th—6th century A.D.) (2,3) has tried to establish atmospheric phenomena asa possible precursor for earthquake prediction. Heproposed that the four elements viz. Wind, Fire,Water, and Indra cause the earth to shake. HarryReid, a geologist in 1910 proposed that it may bepossible to predict the Time and Place of earthquakesby monitoring stress along faults. In seismicallyvulnerable areas like Japan, China, Russia, Mexicoand USA comprehensive research programmes havebeen carried out, so that earthquakes could bepredicted in terms of Location, Time and Magnitude.The study of precursors using earthquakeinstrumental data began in 1949. In 1949 Garmregion of Siberia in Russia was devastated by anearthquake. The Russian scientists tried to investigategeological changes preceeding an earthquake. Thisstudy lasted for two decades. In 1971, the Russianscientists announced that the monitoring of theseismicity gives the important clues about theanomalous behaviour which will help to predictearthquakes. They found that the velocity of P andS seismic waves undergo change when rock in thepotential Epicentral area is under stress. Thesechanges were attributed to an effect called‘Dilatancy’. They found premonitory changes in theratio of seismic compressional velocity to the seismicshear velocity (Vp/Vs) prior to series of earthquakesof moderate size in Garm region

Lynn Sykes and Yash Agarwal, Columbia Universitypredicted an earthquake in 1973 using Dilatancy.Soviet seismologist S.A.Fedotov (5) put forth‘Seismic Gap’ theory as a precursor to predictimpending earthquake. Kiyo Mogi from Japan ( 5)forecast few earthquakes in Japan using ‘SeismicGap’ theory. Studies have been carried out hopingthat Patterns of seismicity exist which arecharacteristic of earthquakes. It is noted that micro

3722 - 24 January, 2011


earthquake activity preceeds some earthquakesusually as foreshocks. The patterns are of three basictypes i) Activation ii) Quiescence iii) Migration ofepicenters. Activation is almost identical toforeshocks; quiescence corresponds to expecting‘quiet before the storm’. Wyss and Baer (1981)predicted a major earthquake on the basis ofquiescence period. Migration of epicenters may beexpressed as that of seismic gap in a seismicallyactive region. A doughnut shaped pattern has beenidentified preceeding the Shimane earthquake of1978 (. 6).

The Chinese approach to earthquake prediction wasmore massive. In 1966, they launched war againstearthquakes. In this attempt they engaged 10,000trained earthquake specialists, 17 nodal centres, 250seismic stations and 5000 observation points. Theymonitored well water level fluctuations, Radoncontent in water, changes in earth’s magnetic field,tilt in the terrain and also behaviour of animals. Usingall these precursors, Chinese could predict Heichengearthquake of Feb.1975 and saved many lives.

Rikitake has compiled several dozen possibleprecursors, both macroscopic and microscopic,identified from the analysis of large volume ofobservational data. He classified those precursorsas i) Long term prediction ii) Medium term predictioniii) Short term prediction and iv) Imminent Predictiontools. Sub commission on Earthquake Prediction byInternational Association of Seismology and Physicsof the interior has proposed forty precursors. Onlyfive were judged as significant and of these five,two were of hydrochemical in nature and importantto Reservoir Triggered Seismicity (RTS). H.K.Guptaclassified 32 various precursors into six classes.These are:-

i) Seismological Precursors: .......................... 13

ii) Geomagnetic and Geoelectric Precursors: ... 4

iii) Atmospheric/ Ionospheric Precursors: ......... 3

iv) Geodetic Precursors: ..................................4

v) Geochemical Precursors: ............................6

vi) Biophysical Precursors: ...............................2

A lot of research has been done in TriggeredSeismicity especially in RTS. Observations suggest

that Pore Pressure Diffusion, Quasi-Static andQuasi-Dynamic Nucleation process before thedynamic rupture of the main shock and Kaiser effectcan be considered as an immediate earthquakeprecursor for small to moderate sized earthquakes.(7, 8).

Methods of prediction based merely on precursoryphenomena are purely empirical and involve manydifficulties. The two important factors i) The stateof the stress ii) Rock strength at Epicentral depthscannot be measured directly. This is the reason whyprediction of earthquakes is normally unsuccessful.

4. Earthquake Precursory Studies in the Stateof Maharashtra, especially in Koyna area:

The State of Maharashtra was seismically stable formany centuries. Therefore no attempts were madeearlier as far as earthquake precursory studies areconcerned. In Maharashtra, earthquake studiesstarted in 1963 after the initiation of seismicity inKoyna project area. Central Water & PowerResearch Station (CWPRS), Pune was the mainorganization undertaking these studies. CWPRSinstrumented the Koyna area with the help ofIrrigation Department, Government of Maharashtraand tried to understand the causes of seismic activity.This study continued for two decades i.e. from 1963to 1982. During these studies various precursorystudies have been undertaken (9). These studiesinclude i) Tilt of the Dam body and also terrain ii)Displacement of the body of the Dam. iii) Strainmeasurements iv) Telluric current studies iv)Seismomagnetic changes v) Seismic velocities Vp,Vs and ratio Vp/Vs vi) ‘b’ values vii) Well levels inhot springs and their discharge There have beeninstances of premonitory variations in the abovementioned precursors preceding large and moderateearthquakes. Tilts, strain in deep underground rock,crustal displacements have been observed in Koynaearthquake region over a decade covering pre &post earthquake periods and their observationsconfirm their reliability for qualitative and quantitativepremonitory indices.

Tilt: Tilt in the Foundation of the Dam was observedsignificantly one or two years before the Koynaearthquake of Dec.1967. Ground tilt measurementsusing water tube tiltmeter located in the Dam gallery


38 22 - 24 January, 2011

showed sudden changes in ground tilt preceeding amoderate earthquake of Mag. 5.2 on 17th

oct.1973.Few smaller earthquakes of M~ 4 have alsoshown similar premonitory changes in ground tilt. Inthe absence of continuity of the monitoring, thisprecursor was not used for further studies.

Strain Measurements: Changes in Strain usingCarlson type Strain meter in deep underground rockwere observed for small earthquakes of Mag. 4.0and above. The observed stress drop was 12 bars.But such strain meters can not adequately registerearth stresses significantly for earthquakes at deeperlevels.

Telluric Studies: Telluric observations did not revealany changes with seismic energy in the Koyna area.

Seismomagnetic Changes: To detect premonitorychanges in the piezo-magnetic field associated withKoyna seismic area, Proton precessionMagnetometer observations were undertaken.Magnetometer located at Koyna did not show anypremonitory changes related to the moderate sizeearthquakes.

Seismic Velocities Vp, Vs, and ratio Vp/Vs:Premonitory changes in Vp/Vs were observed forfew occasions for the aftershocks in the Koyna area.One of the significant premonitory changes in Vp/Vs is observed for Koyna earthquake of 27th June1969, Magnitude 4.7. During subsequent periods,similar observations could not be observed for manyother earthquakes of similar magnitude. As such itis difficult to draw any confirmatory inferences.Another interesting study is (10) ‘P’ wave residualobservations. About 800 earthquake events thatoccurred during Jan.1966 to June 1969 were studied.The study of the ‘P’ wave residual at Koyna revealsthat an increase of about 0.4 sec. in P residualsoccurred in the source region of the Koynaearthquake. This anomalous change appears to haveset in at least a year before the occurrence of theMain shock. The P residual studies appear to beequally well applicable for the analysis ofearthquakes associated with strike slip faulting. Theroutine monitoring of ‘P’ residuals can be regardedas an important tool for predicting earthquakes.

‘b’ Values: The detail Koyna seismic data areavailable for the period 1963-1981. Here, yearly ‘b’

values i.e. Gutenberg-Richter relationships werestudied. It is observed that the ‘b’ values showsignificant changes in the pre and post earthquakedata The pre earthquake values of ‘b’ decreasedslowly whereas post earthquake values of ‘b’increased sharply. Similar studies have beenundertaken by NGRI in Bhatsa area for the period1983-84. Decrease in the ‘b’ values before theearthquake of Magnitude 4.9 and rise in the valuesafter the earthquake is observed. The ‘b’ value is aparameter that may change with time and the wholecalculation is severely affected by data preparation,magnitude bias and data accuracy. Because of theselimitations, ‘b’ values can be taken as an indicatoronly of the seismic potential of the area.

Well levels in Hot springs and their discharge:Monitoring of temperature and discharge of the hotsprings aligned along the coast of Maharashtra havebeen taken for the period 1968-1972. No conclusivecorrelation between Koyna seismicity andtemperature of the hot springs and their dischargecould be established.

Interesting observation is at Killari. In the famousNeelkanteshwar Temple at Killari, the Shivling wasoften surrounded by water. But almost one yearbefore the Main earthquake the water disappeared.Water again appeared after the Main earthquake.But such anomalies could not be identified asprecursors to predict Time and Magnitude of theMain Killari earthquake.

National Geophysical Research Institute, Hyderabadwas also engaged in studying

the Koyna seismicity from the beginning. Numberof Research papers has been published on Koynaseismicity by NGRI scientists. Their detailinvestigations suggest that the triggering ofearthquakes in the Koyna region is influenced by i)Rate of loading ii) The highest water levels reachediii) Duration of retention of high water levels iv)Kaiser effect (7). To understand the physics of thetriggered earthquakes and possibly to forecast themedium size Koyna earthquakes NGRI concentratedtheir studies on Koyna region. Observing the factthat the Koyna earthquakes occur in a small area of30km × 20km and their focal depth is limited to 12km and also earthquakes of M e” 4.0 occur everyyear, a systematic research program is carried out

3922 - 24 January, 2011


for last two decades. Rastogi et.al. (8) Studied therupture nucleation of few Koyna earthquakes andconcluded that nucleation zone migrates towardsNorth. The growth rate of nucleation zone variesfrom 0.5 to 10 cm/sec. The nucleation zone finallyattains a length of about 4 to 8 km just before the

occurrence of Main shock. It is also observed thatthe growth of foreshock number with time suggestsa quasi-static(slow increase of foreshock frequency)and quasi-dynamic (rapid increase of foreshockfrequency) nucleation process before the dynamicrupture of the Main shock that can be considered asan immediate earthquake precursor for small tomoderate sized Koyna earthquakes. In 2005, NGRIhas put one step ahead and started real timeearthquake monitoring and analysis which includes7 to10 well established seismological observatoriesand many precursory studies like well levelobservations, Radon measurements and gravitystudies etc. as multi parametric studies in Koynaarea. Based on reservoir data and earthquake data,following forecast was made in September 2005 (11).

Forecast: The forecast was made during third weekof Aug.2005.There is a high probability of theoccurrence of an M ~ 5 earthquake in the weeks tofollow. If M ~ 5 earthquake do not occur till the endof Dec.2005 this be considered as a false alarm. Ifwe succeed in identifying the nucleation when it ishalf way through we shall be able to make a shortterm forecast one or two days before the event. Itwas further noted that as Koyna area hasexperienced two earthquakes of M e” 4.0 within 16

days, probability of earthquake of M e” 5 is enhancedat Koyna.

Result: An earthquake of Magnitude 4.5 occurredon 30th Aug.2005. Short term (one or two days beforethe event) prediction was not done. Attempts offorecast done by NGRI scientists are as below.

This attempt is a remarkable development in the fieldof earthquake precursory studies. Since Aug. 2005,there are more than 60 earthquakes of magnitudeM e” 3.0. Out of those, identification of cluster offoreshock nucleation for 6 earthquakes is possibleand forecasting in real time for two earthquakes ispossible.

Precursory changes of Stress Drop, Cornerfrequency are observed for five earthquakes ofmagnitude ranging from 4.1 to 4.7. This study wasfor the period 1994 to 1998.

NGRI had also monitored well water level fluctuationsin 21 observation wells for more than 10 years. Co-seismic changes have been observed for localearthquakes of M e” 4.3.

Anomalous electron density variations are observedduring the study of the F2 region of ionosphere duringthe period of Main Koyna earthquake.

Comprehensive analysis of past One Hundred yearsof earthquake data reveals that earthquakes can bepredicted using planetary configurations with fairaccuracy with regard to Time, Location andmagnitude. (Ref. ).

Significant temporal changes in ä13 C, carbon-13isotope precursory studies are observed.

Nucleation Observed on Forecasted on Earthquake occurred on Remarks

First week of August 2005 Third Week of August 2005 for M ~ 5

30 August 2005 M 4.5 (MERI) M 4.8 (NGRI)

Earthquake occurred on 20/11/2005(4.0) also.

Nucleation observed ----- 13 Nov.2005 Not forecasted Nucleation observed ----- 26 Dec.2005 Not forecasted

Nucleation observed ----- 17 Apr.2006 Nucleation lasted for 380 hours, Not forecasted

April 2006 16 May 2006 for M~ 4

21 May 2006 M 3.9 (MERI) M 4.2 (NGRI)

---

----- 10 October 2007 M ~ 4

14, Oct.2007 M 3.1 (MERI) M 3.4(NGRI)

Not felt in koynanagar. Felt in Warnavati and Chikhali


40 22 - 24 January, 2011

5. Conclusions:

Various precursors have been studied and observedfor the last forty-five years to predict Koynaearthquakes. But no precursor except Nucleationof foreshock cluster seems to be reliable forpredicting impending Koyna earthquake.

Looking at the above precursory studies in Koynaarea, it seems that, in the forecasting attempts theuse of real time analysis of Stress Drop, Cornerfrequency, Deep well level observations, ‘b’ values,Vp/Vs or Tp/Ts, Changes in P wave residuals alongwith Nucleation of foreshock cluster will enhancethe prediction probabilities of earthquakes in Koynaarea.

6. References:

1. Report of The Experts committee on seismology,Irrigation Dept., Govt. of Maharashtra, Mumbai,(1995).

2. Lele V.S., Tambat S., Lele Y.S., (2003).Earthquakes, References from the Rigveda tothe Rajatarangini, Pub by Sanskrit SanskritiSamshodhika, Jnana Prabodhini, Pune.

3. Iyengar R.N., Earthquakes in ancient India

4. Guha S.K. et.al, Koyna Earthquakes (1974),Central Water and Power Research Station,Pune

5. Hemmady A.K.R., Earthquakes, National BookTrust, India (1996).

6. Scheidegger A.E., Thirty lectures on Seismicity(1981), Cent. Water & Power ResearchStation, Pune

7. Gupta H.K.,(2005)., Artificial water reservoir-triggered earthquakes with special emphasis atKoyna, Current Science, Vol.88, No10.

8. Rastogi B.K., Mandal P. Foreshocks andNucleation of Small to Moderate sized KoynaEarthquakes (India), Bull. Seism. Soc. .Am., 89,1999.

9. Guha S.K. et.al (1974). . Koyna Earthquakes(1963 to 1973), CWPRS, Pune

10. Saxena A.K., Gaur V.K., Khatri K.N., P-Residual studies around Koyna DamRegion, Maharashtra, India, Department ofGeology, University of Roorkee.

11. Gupta H.K. et.al. (2005). An earthquake of M~ 5 may occur at Koyna, Current Science,Vol. 89, No.5.

12. Rastogi B.K.et.al., Precursory changes insource parameters for the Koyna-Warnaearthquakes, Geophysical Journal International,Vol.158, Issue 7, pp 915-921.

13. Chadha, R.K., Pandey, Ajeet P. and KuempelH.J., (2003), Search for earthquake precursorsin well water levels in a localized seismicallyactive area of Reservoir Triggered Earthquakesin India: Geophys. Res. Lett., v. 30 (7), p. 1416.

14. Chadha, R.K., Kuempel H.J., Shekar M.,Reservoir triggered Seismicity (RTS) and wellwater response in the Koyna-Warna region,India., Tectonophysics ,Vol.456, Issue 1 to2.,2010.

15. Sharma K., Das R.M., Dabas R.S., PillaiK.G.M., Garg S.C., Mishra A.K., (2008).Ionospheric Precursors observed at low latitudesaround the time of Koyna earthquake, Advancesin Space Research,.42 (7) , 1238-1245.

16. Venkatanathan N. et.al. (2005). Planetaryconfiguration: Implications for earthquakeprediction & occurrence in Southern peninsularIndia. J. Ind. Geophys. Union,.9,(4), 263-276.

17. Sukhija B.S., Reddy D.V., Najabhushanam P.,Significant temporal changes in ä13 C of groundwater related to reservoir triggered seismicity.Seismologic Research Letters, Seismologicalsociety of America, Mar. 2010.

18. Reddy D.V. et.al. Radiation Measurements,Vol.45, Issue 8, Sep.2010 pp 935-942.

4122 - 24 January, 2011


S5_C10

Earthquake pre-cursory studies in Koyna-Warna region, India: Some vital observations

D.V. Reddy (E-mail:[email protected]) andP. Nagabhushanam (National GeophysicalResearch Institute (Council of Scientific andIndustrial Research), Uppal Road, Hyderabad –500 007 (India).

To capture the seismogenic precursory signaturesin real time, exploratory experiments involvinghydrochemical and soil gas Radon (Rn)measurements in Koyna–Warna region, India, wereinitiated in 2005. Periodical groundwater samplinghas been made from 12 bore wells out of 21 (90 to250 m deep) drilled for the pore pressure studiesand two hot springs, besides surface water samplingfrom Koyna and Warna reservoirs. During the studyperiod (2005 – 2010), it is observed that the Govarewell has been unique in showing precursory chemistrychanges in response to the seismic events (Me”5).The Govare well recorded maximum changes inChloride, Sulphate, Fluoride and 18O isotopic ratio(d18O) during the 14 March 2005 earthquake (M5.1). Since August 2006, its precursory chemistryhas gradually increased, with decreasing d18O, tomiddle of 2009. The changed chemistry has shownno relation with groundwater recharge. A model isproposed to account for the precursory chemistrychanges, wherein mixing of two chemically differentwaters takes place facilitated by micro fracturesgenerated due to seismic stress. Projection of theprecursory linear chemical changes observed tillMarch 2009, to the level recorded during 2005earthquake (M 5.1) has shown the time window foran impending Me”5 earthquake. The window was2012/13 or 2011/12 from the August 2006 datum.The projection based on exponential increase,advanced the time window to 2010/11. The projectedearthquake happened on 12 December 2009 (M 5.1),while studies were still going-on. Based on Koyna’s40 year earthquake history, the statistical estimateof recurrence interval of earthquakes (Me”5) inKoyna is 5 year, which lends support to the projectedseismic event.

Additionally, hourly monitoring of electricalconductivity (EC) of Govare well water and the soilgas radon measurements at 60 cm depth in real time

have provided strong precursory signatures inresponse to two earthquake (M 4.7 on 14.11.2009,and M 5.1 on 12.12.2009) that occurred in the studyregion. For M 5.1 earthquake, the EC recorded pre-seismic (~40 hours earlier) and also post-seismicperturbations (~20 hours after), but for the M 4.7earthquake, it had only post-seismic signature (8 daysafter). Another precursor, the Rn had shown pre-seismic increase ~20 days in advance for both theearthquakes, while the co-seismic signature was lessby 50% and 30% respectively from their peaks. Allthe observed precursory signatures are attributed tothe phenomenon of opening and closing of microfractures due to seismic stress. On-line monitoringof these two parameters may be useful to check theentire chemistry changes due to earthquakes, and itmay help to forecast the impending earthquake(s).

S5_C11

Detection of possible precursors of the 2010Chile earthquake using superconductinggravimeters and broadband seismometersrecords

Jun Yi1, Wen-Bin Shen1,2( 1 Department ofGeophysics, School of Geodesy and Geomatics,Wuhan University, China, 2 Key Laboratory ofGeospace Environment and geodesy, WuhanUniversity, China.E-mail:wbshen@sgg,whu.edu.cn)

Scientists have great interest in finding precursorsof large earthquakes. In this study we focus ondetecting possible precursors of the Mw 8.8 Chileearthquake event occurred on 27 February 2010based on both the Superconducting Gravimeters(SGs) under the Global Geodynamic Project (GGP)and the Broadband Seismometers (BBSs)supervised by the Incorporated Research Institutionsfor Seismology (IRIS). Due to the non-linear andnon-stationary characteristics of both the SG andBBS data, we use the Hilbert-Huang Transform(HHT) to analyze the records, in which the EnsembleEmpirical Mode Decomposition (EEMD) is adoptedto obtain intrinsic mode functions (IMFs) and time-frequency-energy spectra. Analysis of the recordsin quiet periods provides quite uniform time-frequency-energy distributions located within twofrequency windows, taken as background spectra.Then, we analyze 1-Hz data recorded at about ten


42 22 - 24 January, 2011

SG stations and 20-Hz data recorded by more thanten BSS stations covering several days before theChile event, and we find that almost half of therecords show that there are anomalous signals priorto the 2010 Chile event, which might be the possibleprecursors. The present study is preliminary andfurther investigations are in progress. This study issupported by Natural Science Foundation China(Grant No. 40974015).

S5_C12

Seismic Acoustic Emission (SAE) as anearthquake precursor

G. Suresh and R. S. Dattatrayam (IndiaMeteorological Department, Ministry of EarthSciences, Lodi Road, New Delhi-110003).

Seismic Acoustic Emission (SAE) produced in theearth’s crust play an important role in understandingthe tectonic stress regime of a region. The abruptchanges in SAE measured in deep boreholes arerelated to stress state variation in a local crustalvolume before a possible earthquake. These changesare a direct result of disturbances in the crust andcan serve as reliable short term precursors ofearthquakes (Belyakov et al. 2002). In order tocarryout continuous measurements of SAE in India,India Meteorological Department (IMD), under anIndo-Russian collaboration (Integrated Long TermProgram of Cooperation of Department of Science& Technology), set up a borehole seismic acousticrecording system comprising of tri-axial magneto-elastic acoustic geophone (Model No. MAG-3B,manufactured by Russian Academy of Sciences) inOctober, 2007. The sensors are deployed in a watertight and re-usable borehole at a depth of about 100mat Ridge Observatory, Delhi. The sensor is based onmagneto-elastic conversion of the rate of change ofinertial force to an electrical signal measured in abroad frequency range of 20Hz to 2000Hz. The datais recorded in one-third-octave acoustic frequencybands centered at 30, 160, 500 and 1200Hz in a 6-channel 12-bit A-D converter installed in a PC. Thesignals in each band are averaged for 1 minute anddigitized before storing in the memory.

The equipment is observed to be sensitive to localearthquakes of magnitude 4.0 and above occurringwithin a distance of 100km from the observatory.The system has recorded a local earthquake of

magnitude 4.5 on 25th November, 2007 with itsepicenter at a distance of 16.8km from the Ridgeobservatory. It was observed that the signal amplitudeprogressively increased by eight folds, 30 min priorto the event in the 30Hz and 160Hz frequency bandsin comparison to higher frequency bands. However,the data does not show any significant increase inthe signal amplitude for several local earthquakes ofmagnitude less than 4.0, which have occurred withina distance of 100km from the observatory. Further,the long-term variations in the SAE indicate somecorrelation with Sun-Moon tides. It is also observedthat cultural noise has a significant effect of maskingthe signals, particularly for the low magnitude events.It would be useful to deploy a network of at leastthree such systems each in seismically active areas,such as NW Himalaya, NE India etc., in a site whichis free from industrial and cultural noises, to be ableto make the best use of the recorded data foridentifying precursory signals. An attempt has beenmade in this paper to discuss the salient features ofthe borehole system along with some results.

S5_C13

Study of multi-parameter gas-geochemicalprecursor signals of a distant earthquakerecorded simultaneously at two thermal springsin India.

H. Chaudhuri1(E-mail: [email protected]),D. Ghose1, R. K. Bhandari1, P. Sen2, and B.Sinha1 ( 1 Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata - 700 064, India, 2 SahaInstitute of Nuclear Physics, 1/AF Bidhannagar,Kolkata - 700 064, India)

Investigations dealing with the forecasting techniquesof natural calamities like cyclones, thunderstorms,floods, earthquakes and tsunamis have become animportant research trend. Among these naturalhazards, earthquakes and tsunamis are the mostdestructive, in terms of loss of life and destructionof property. The present paper deals with thetechnique of short term earthquake precursors usingseismo-geochemical monitoring. Continuous He and222Rn along with gamma dose rate weresimultaneously monitored for pre-seismic signaturesat two thermal springs in India. The monitoringstations are placed in dissimilar geological

4322 - 24 January, 2011


environments and in different seismic zones of thecountry and are separated by a distance of 1612km. One of the monitoring stations is located at thethermal spring site at Bakreswar which lies inthe eastern part of the country in a moderate riskzone - seismic zone III. The other monitoringstation is situated at the Tatta Pani thermal springsite which falls in the north-western part of thecountry in a high risk zone - seismic zone IV.Bakreswar is close to the extinct (115Ma) Rajmahalvolcanics of the Chotanagpur gneissic complex inWest Bengal while the other spring at Tatta Pani islocated in a non-volcanic geothermal area that lieswithin the mountain folds of Jammu & Kashmir,situated in proximity to the Main Boundary Thrust(MBT) of the Lesser Himalayas. In this paper, wemake a cross correlation study, using nonlineartechnique, of the simultaneously recordedgeochemical data from the two thermal springs. Theanomalous fluctuations in the spring gases observedduring the period December 24-27, 2007 at both thethermal springs may be correlated to the distant (~1000 km) China earthquake of magnitude M=6.3 thatoccurred on January 09, 2008. Based on the obtainedsequence of data points we attempt to make a timeseries analysis to relate magnitude and epicentraldistance through statistical methods and empiricalequations related to the zone of influence. Thesegeochemical anomalies recorded at distant sitesappear to be a potential tool to deal with thecommonly debated question of earthquakeprecursors.

Keywords: Thermal spring, geochemical anomaly,helium, radon, gamma, time series analysis, nonlineartechnique, earthquake precursors

S5_C14

Predictability of Valsad Earthquake SwarmsGujarat, India

H.N.SRIVASTAVA andS.N.BHATTACHARYA (Formerly in IndiaMeteorological Department). D.T.RAO andS.SRIVASTAVA (Gujarat Engineering ResearchInstitute, Vadodara).

Valsad district in south Gujarat near the westerncoast of the peninsular India experienced earthquake

swarms since early 1986. Seismic monitoring througha network of microearthquake seismographs showeda well concentrated seismic activity over an area of7x10sq.km with the depth of foci extending from 1to 15 Km. A total number of 21830 earthquakeswere recorded during March 1886 to June 1988. Thedaily frequency of earthquakes for this period wasutilised to examine deterministic chaos throughevaluation of strange attractor dimension andLyapunov exponent. The low dimension of 2.1 forthe strange attractor and positive value for theLyapunov exponent suggest chaotic dynamics inValsad swarms with at least 3 parameters forearthquake predictability. The results have also beendiscussed to indicate differences in chaoticmechanism between interplate and intra plateearthquakes in the Indian region.

S5_C15

The analysis of microseisms before the 2008great Wenchuan earthquake

Xiao-Guang Hao, Xiao-Gang Hu*(KeyLaboratory of Dynamical Geodesy, Institute ofGeodesy and Geophysics, Chinese Academy ofSciences,E-mail: [email protected],[email protected])

We investigate microseisms recorded by broadbandseismographs in mainland of China before the 2008/05/12 great Wenchuan earthquake. Our resultsindicate that the microseisms consist of two mainparts which have totally different dynamicalcharacters. The part in the frequency band of0.2~0.25Hz is related to a typhoon namedRammasun, which was evolving from 9 May to 13May 2008 with its maximum at 11 May. This type ofmicroseism is strong at seismic stations near thecoastline of China but weak at stations in the inlandof China. Another one in the frequency band of0.12~0.17 Hz bears no relation to Rammasun. Theenergy of this non-typhoon microseism has slowlyincreased since May 10, but it starts a dramaticincrease at 10 hours before the earthquake andreaches the maximum just before the greatearthquake outburst, and it is strong near theepicenter of the earthquake but comparatively weakin the coastline of China and Western China.


44 22 - 24 January, 2011

We locate sources regions for the typhoon-relatedmicroseism and the non-typhoon microseism by thesource scanning algorithm, respectively. The resultsshow that the typhoon-related microseism isgenerated at coastal region when swells fromRammasun impact shorelines, but the source regionof the non-typhoon microseism are distributed aroundthe epicenter of Wenchuan.

S5_C16

Multi-Parametric Geophysical observations atGhuttu, Garhwal Himalaya: Radon component

V.M.Choubey(Email: [email protected]);B.R. Arora, Naresh Kumar and Leena Kamra(Wadia Institute of Himalayan Geology,33, GeneralMahadeo Singh Road, Dehradun 248001, India)

The Multi parametric geophysical observatory(MPGO) established at Ghuttu in Garhwal Himalayadesigned to study the earthquake precursors in anintegrated manner. The observatory is equipped withOverhouser magnetometer, flux gate magnetometer,superconducting gravimeter, ULF-VLFmagnetometer, radon & water level monitoringsystem, seismographs and GPS system. A 68 mdeep borehole, penetrating into the water table isincorporated for taking continuous radon monitoringat two depth points from the surface. Onemeasurement is taken at 10 m (in the air column)and the second one at 50 m (within water column)depths. Besides radon concentration, air temperature,water temperature, atmospheric pressure, rainfall andwater level fluctuations are also recorded in theborehole site with sampling interval of 15 min.

The continuous time series of radon variationalong with other environmental parameters of 3 years(2007 to 2009) shows a rich and complex pattern oftemporal changes in radon including well-definedseasonal and diurnal variation. The radon data is non-stationary and exhibit non-constant variance withvery low changes in background level in winter andhighly fluctuation in summer. The radonmeasurements at 10m depth show a well-defineddiurnal pattern in concentration that is havingminimum value in the early morning and maximumin the afternoon. The analysis of three years dataindicates that this daily variation is well correlatedwith atmospheric temperature. Examination and

correlation of radon with environmental factors hasrevealed that when atmospheric temperature is lessthan that of water temperature in the borehole, thevariation from background level is negligible.However, when the atmospheric temperaturesurpasses the borehole water temperature, peaksdiurnal pattern are observed in summer. Althoughthe similar higher atmospheric temperature existsduring rainy season also but following continuousrainfall, once the soil/rocks are saturated with water,radon concentration show fair stability with high valuethan average. Long pauses in rainfall give jerkyvariability during rainy season with no clear patternof daily variation. The recorded radon data stronglysuggest that the atmospheric temperature and rainfallinfluence the variability of radon emanation thereforethese anomalies has to be removed first whilesearching precursory signature in this continuousradon data.

S5_P1

Thermal and ionospheric anomalies associatedwith the Haiti earthquake of January 12, 2010

Suryanshu Choudhary(Email: [email protected]);Shivalika Sarkar and A.K.Gwal (Space ScienceLaboratory, Department of Physics, BarkatullahUniversity, Bhopal-462026, India)

This paper examines the anomalous variations ofatmospheric and ionospheric parameters observedaround the time of a strong earthquake (Mw 7.0)which occurred in Haiti region (18.457°N, 72.533°W287.47E) on 12 January 2010. Sea Surfacetemperature (SST) data obtained from NOAAAVHRR satellite has been used to study the thermalanomalies associated with this great earthquake.Wavelet analysis of the NOAA AVHRR data showsdecrease of the sea surface temperature severaldays before the Haiti earthquake. In addition we havealso used the DEMETER satellite data to study theplasma parameter variation during the Haitiearthquake. Increase of the plasma parameters hasalso been observed one day before the occurrenceof the main shock. Statistical processing of theDEMETER data, together with SST datademonstrates the possibility of an early warning ofan impending strong earthquake.

4522 - 24 January, 2011


S5_P2

Earthquakes in Uttaranchal Himalaya, India.

ARUN K SHANDILYA(E-mail: [email protected]);ANURAG SHANDILYA (Department ofApplied Geology, Dr. Hari Singh Gour University,Sagar 470003 (M.P.) INDIA).

On the basis of the seismic records of seismicevents in Uttaranchal a review of the events havebeen done and probabilities of the earthquake hasbeen workout in the part of Garhwal-Kumaun-Himalaya in Uttaranchal. In the southern part ofouter Himalaya thrust zones are expected toproduce a long term probabilities of largeearthquakes of magnitude more than 6, on Richterscale which have on and average 5 to 20 mmreactivation and neotectonic upliftments along theshear zones. These zones have estimated to havefuture probabilities of earthquakes on these areaswhich are based on the historical seismic records,the long term slip rate and the displacement causedby the previous seismic events. The historicalrecords of seismic events in these part of theHimalaya have the earthquake intensities varyingfrom 4 to 6.0 on Richter scale in the geologicalpast. The Kangra earthquake (1905) was recordedmore than 7.0 Richter scale, Garhwal Earthquake(1883), (6.0), ‘Uttarkashi earthquake’ (1920), 1991(5.6, 6.8) respectively, Chamoli earthquake (1999),6.5 and the Dehradun earthquake of (1970). Theapproach followed for calculations of probabilitiesemploy the estimated recurrence times with amodel that assumes probability increases withelapsed time from the large earthquake on the fault/thrust zone areas. Through the calculatedprobabilities the estimated natural disaster/hazardsin the newly born state of Uttaranchal in Himalayanbelt can be reduced.

Key Words- Himalayan thrust, Recurrencetime, elapsed time, rupturing

S5_P3

Low Field Magnetic Measurements: AModern Tool for Prediction of Earth-Quake

By Dr Rajeev Vaghmare (GRIIC, GERMIGandhinagar).

On and average an earth’s magnetic component atthe equator of the earth is about 40,000 gamma.

This value of earth’s magnetic field changes fromplace to place on the earth. Low field strengthmagnetometer is a useful tool for sensing the changesof the EARTH’s MAGNETIC Field with the internalchanges in the earth’s crusts.

The minor changes to the tune of +/- 1.0 gamma,field strength can lead to conclude the prediction ofthe EARTH-QUAKE at least THREE hours beforeits’ actual occurance.

These kind of low filed strength measurements aredone using M/S BARTINGTON make MAG01magnetometers , which can measure the changes inthe earth’s magnetic component at a given place

And further a correlation can be established usingthe changes in Magnetic Filed as function of intensityof an earth-quake likely to struck at a given place.

The interesting fact is that the empirical equationscan be established between CHANGE inMAGNETIC FIELD and the Intensity of the EarthQuake. The rate of the change of the magneticvalues can also be extrapolated to the time of theoccurance of the EARTHQUAKE at the givenplace.

Concludingly, the low field strength measurementtechnique can act as very useful tool for the EARTHQUAKE predictions.

Acknowledments #

The Author is thankful to GERMI Authorities forthe kind permission accorded for submitting theabstract to International Symposium on “ The 2001Bhuj Earthquake and advances in EarthquakeScience” being held during 22-27 January 2011.


46 22 - 24 January, 2011

S5_P4

Foreshock clustering as Precursory Patternfor the Kachchh Earthquakes in Gujarat,India.

Sandeep Kumar Aggarwal(Email: [email protected]); B. Sairam,Santosh Kumar and B.K.Rastogi (Institute ofSeismological Research, Village Raisan,Gandhinagar)

As the aftershock activity to M5 level is continuingin the rupture zone of 40 km X 70 km, we studiedclustering pattern of aftershocks of 2001 Mw 7.7Earthquake in Kachchh. The activity has alsoexpanded to nearby faults. Presently clusteringoccurs along North Wagad Fault and Gedi Fault. Asthe seismicity is monitored by dense network of morethan 20 broadband seismographs in Kachchh activearea of about 60kmX60km, the earthquake locationsare precise and it has been possible to observeforeshocks clustering prior to eight mainshocks ofMw 3.8 to 4.5 during 2007 to 2009 with the followingdetails:

Numbers of Foreshocks in different cases are 4 to70 (with two or more shocks of M e” 3.0).

Radius of Clusters is 4 to 25 km.

Duration of Clusters is 7 to 25 days.

Quiescence of 1 to 6 days is observed for six cases.

The precursory observation found is that if the shockscluster at depth of 15 km to 30 km along with 2 to 7shocks of Magnitude e” 3.0, a Mainshock of M4 to5 occurs. In one case of mainshock along Gedi Fault(Mw 4.1 on 15 Apr 2008) the focal depth of theMainshock and foreshocks are 10-14 km.

It has to be mentioned that similar clusteringobserved at other times was not followed by M~4mainshocks. The pattern of clustering appears to bea useful precursor, as one M4.5 mainshock onSeptember 5, 2009 was in-house predicted a day inadvance from cluster model as there were 7foreshocks of M 3 to 3.7 and 60foreshocks of M 0.5to 2.9 in 40km X 20km area during 10-days periodfollowed by a day’s quiescence.

Key word: Clustering, Seismicity, Quiescence,Foreshock, Mainshock, Kachchh

S5_P5

Status of Superconducting Gravimeter andMPGO Network of Kachchh.

Arun Gupta (E-mail: [email protected]),Rashmi Pradhan*, M.S.B.S. Prasad and B.K.Rastogi (Institute of Seismological Research,Raisan, Gandhinagar-382 009, Gujarat. *Ministry ofEarth Sciences, New Delhi)

A very sensitive dual sphere superconductinggravimeter (SG-055) was installed on March 01, 2009at Badargadh (BG) in Kachchh (Lat 23.47ºN, Long70.57 ºE). This site is seismically active and free fromcultural noise. It is surrounded by Rann of Kachchh(salty waste land) in three directions (N,E and W) atabout 20-30km distance and Ocean coast in S at about50-80km distance. After removal of spikes and offsets,continuous record of about one year gravity changesshow the dominating effect of solid earth tides, oceanloading and atmospheric pressure. Available rainfalland geohydrological data do not show significant effecton gravity records. Earth’s free oscillations excitedby some large earthquakes are well recorded on SG.Besides some large and moderate earthquakes, co-seismic changes have also been observed duringearthquakes of Mw e” 4 within periphery of 80 kmfrom Badargadh. SG was installed as a part of Multi-parametric Geophysical Observatory (MPGO)instruments and SG data will be supplemented byseveral other parameters.

Institute of Seismological Research (ISR) hasestablished a network of four MPGOs at Bhachau,Vamka, Desalpar and Badargadh in Kachchh whichis operational from March 2009 and fall in theaftershock zone of 2001 Bhuj earthquake (Mw 7.7)for earthquake precursory research. Severalseismological / geophysical / geochemical parametersare under continuous monitoring through otherMPGO instruments like Very Broad BandSeismometer (VBBS), Strong Motion Accelerometer(SMA), Global Positioning System (GPS) and radonrecorders at all the four sites. Borehole strainmeterswill be installed shortly at three sites. Fluxgatemagnetometer is installed at Desalpar and Vamka.Further, water level recorder is installed at Desalpar.Five water level recorders will be installed shortly inthese areas. ULF/VLF induction coil magnetometer,Declination/inclination magnetometer, overhausermagnetometer and helium recorders are to bepurchased. Some of the preliminary results will bepresented and discussed in the meeting.

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simple response analysis using the estimated soilstructures due to the MASW survey supported theresults. Thus, in Anjar, site effect for seismic damagecan be suggested.

S6_C2

Determination of Site Amplification in theNorthern Iran from Inversion of Strong-MotionRecords

B. Hassani, H. Zafarani (International Instituteof Earthquake Engineering and Seismology,E- mail: [email protected])

The amplification of strong ground motion at sites inthe Northern Iran is determined using thegeneralized-inverse method. Site-amplificationestimates are determined at 60 strong-motion sitesthat provided horizontal-component records from 45earthquakes of magnitude M4.0 to M7.3 in theregion. The inverse problem was solved in 20logarithmically equally spaced points in the frequencyband from 0.4 to 15 Hz. To obtain a unique inversesolution, a frequency-dependent site amplification asa constraint was imposed to two reference siteresponses. So, the site response estimates aredetermined relative to the spectral level recorded attwo selected reference sites. Average site responsevalues were correlated to the average shear wave

S6: Seismic Wave Propagation, Soil Amplification and Basin Effects Convener : J.P. Narayan

THEME

Significant differences in structural damages in basins as compared with the surroundingexposed rocks or even in a basin itself from place to place have been observed duringthe past earthquakes. The theoretical studies have revealed that assessment of soilamplification and resonance frequency for layered soil deposit in basin using an empiricalrelation is erroneous. The recent researches have also revealed that basin-edge, shapeand size of basin and the basement topography play an important role in altering theground motion characteristics. In light of above, the research papers dealing with thefollowing aspects are invited for presentation and discussions during the symposium.

a. Assessment of soil amplification and resonance frequency using experimentaltechniques like standard spectral ratio method, horizontal to vertical spectral ratiomethod and H/V ratio method.

b. Assessment of soil amplification and resonance frequency in a basin using analyticaland numerical techniques.

c. Numerical and analytical methods for simulation of seismic wave propagation.d. Seismic microzonation of basin.e. Assessment of effects of basin geometry and surface topography on the ground motion

characteristics

S6_C1

A Possibility of Site Effects due to the pastEarthquakes at Anjar, Gujarat State, India

Fumio Kaneko1 ([email protected]),B.K.Rastogi2, A.P.Singh2 ([email protected],),B.Sairam2 ([email protected]),Sudhir K. Jain3 ([email protected]),Shukyo Segawa1 [email protected]),Jun Matsuo1 ([email protected])(1 Oyo Internationa Corporation, Tokyo, 2Instituteof Seismological Research, Raisan, Gandhinagar,Gujarat (India)-382009, 3 IIT, Gandhinagar)

It is well known that site effects contribute to damagedue to earthquakes for a long time. This was for thefirst time pointed out at Anjar for the 1819 greatKachchh earthquake and then again for the 1956Anjar earthquake and the 2001 Bhuj earthquake. Forcheck this effect by detecting site responsecharacteristics and soil conditions, single H/Vmicrotremor (ambient vibration) survey, MASW(shallow seismic surface wave exploration) andearthquake observation were conducted at damaged,less- and non-damaged locations. As the result, thesingle H/V microtremor survey and the earthquakeobservation showed a clear difference betweendamaged and non-damaged locations. Also, the


48 22 - 24 January, 2011

velocity in the uppermost 30m, in high and lowfrequency bands. The peak frequencies of siteamplifications estimated by the generalized inversionmethod were coincided with those of horizontaltovertical (H/V) spectral ratios for the S-waveportion of records. However, due to the shortcomingsof the H/V ratio technique, a perfect matching inamplitude was not obtained. For two frequencybands, the average of site response spectra werecomputed and related to the shear wave velocity inlogarithmic scale. It is a good idea to plot the residualsagainst the independent variables (magnitude anddistance) to see if they show atrend. The predictedFourier spectral amplitudes agree well with availableIranian strongmotion data, as evidenced by the near-zero average of differences between the logarithmsof the observed and predicted values (residuals) forall frequencies and the lack of any significant residualtrends with distance and magnitude.

Keywords: Generalized inversion, Site response;Northern Iran.

S6_C3

Estimation of Dynamic Properties of LucknowSoil

T.G. Sitharam (Professor, Department of CivilEngineering, Indian Institute of Science,Bangalore, India – 560012;[email protected]);S. M .Patil (.Research Scholar, Department ofCivil Engineering, Indian Institute of Science,Bangalore, India – 560012;[email protected])

In critical task of providing the solutions to earthquakegeotechnical engineering problems the dynamicproperties of soils play a major role in the regimes oflinear, intermediate and high levels of strain. Forthese above considerations of importance, in thispaper we are estimating the Shear modulus (G) anddamping ratio (D) variations as a function of appliedstrain (ã) for soil collected from the specific sites ofGomathi river bank in Lucknow city. This Lucknowsoil is studied as a sand silt mixture by taking intoaccount the effect of added non plastic fines on thedynamic behavior. The geographical location of theLucknow city in the Indo Gangetic basin with loosealluvial deposits and its vulnerable distance fromcentral seismic gap (Garhwal-Kumoun Himalaya)has made Lucknow a place of prominence for seismic

liquefaction studies. Here the soil is tested at constantrelative densities (RD) for different silt contents (%)in cyclic triaxial testing equipment at stress controlledconditions and it is observed that the limiting finescontent (LFC) affects the shear modulus (G) anddamping ratio (D) by proportionately decreasing withsilt content till LFC is reached and thereafter itshows an approximate constant behavior.

S6_C4

Liquefaction Susceptibility of Lucknow Soil

T.G. Sitharam (Professor, Department of CivilEngineering, Indian Institute of Science,Bangalore, India – 560012; E-mail:[email protected]);S. Patil (Research Scholar, Department of CivilEngineering, Indian Institute of Science,Bangalore, Inida – 560012; E-mail:[email protected]);Ravi S. Jakka (Post-Doc, Centre forinfrastructure, Sustainable Transportation andUrban Planning (CiSTUP), Indian Institute ofScience, Bangalore, India – 560012; E-mail:[email protected])

Seismic microzonation of urban centers is aneffective mitigation tool to minimize seismic hazards,particularly for those cities which are located in highseismic zones. Lucknow is a fast growing urbancenter and is situated very close to the Himalayancentral seismic gap, where a very high magnitudeearthquake event is anticipated. Seismicmicrozonation studies require the evaluation ofliquefaction susceptibility of local soils to assess thelocal site effects on the associated geotechnicalseismic hazards. Here in this paper, studies carriedon the liquefaction behavior of Lucknow soils usingstress controlled cyclic triaxial tests are presented.Effect of variation of fines content on the liquefactionresistance of Lucknow soil is evaluated based onthe constant global void ratio approach. Resultsshowed that limiting silt content plays an importantrole in the cyclic resistance of the soils. Initially, asfine content increases, the liquefaction resistance ofthe soil is decreased till the limiting silt content, andthereafter further increase in silt content increasesthe liquefaction resistance of the soil. It is observedthat these variations on the liquefaction resistanceof soils are closely related with variations in therelative density. For a given silt content, cyclic

4922 - 24 January, 2011


resistance increases with increase in relative density(ie. decrease in void ratio) of the sand-silt mixture.

S6_C5

Site Characterization: Which Dataset to Use?

Manish Shrikhande(E-mail: [email protected]), and SusantaBasu (Department of Earthquake Engineering,Indian Institute of Technology RoorkeeRoorkee-247667. INDIA);

A set of mainshock and aftershock data followingChamoli earthquake of March 29, 1999, recorded ata single station has been studied. Particularly, theutility of the use of aftershock/weak motion data forsite characterization in seismic microzonation studiesis investigated. The analysis of mainshock andaftershock data indicates that the spectral shape andamplification is quite different during mainshock andaftershock. This, in turn implies that the use of weakmotion/aftershock records may lead to erroneousconclusions regarding the expected ground motionduring a strong earthquake.

S6_C6

The Ground Effect of the SKOPJE 1963earthquake, Again

Apostol Poceski (Fac. of Civil Eng.Univ.SentCyril & Metodi, Skopje, E-mail:[email protected]),R.Macedia (now retired)

The earthquake was of magnitude 6.0, the focus onabout 8 km of the city center, of “shock type” –shallow, short duration, main portion probably notmore than 2-3 sec. There was amplification possiblyup to 3 times, maximum acceleration up to 50-60%g (at that time – 1966, unbelievable).

The damage distribution was explained in terms ofthe seismic response of surficial soil layer. Thereexists a generally good correlation between thedistribution of damage, the thickness of the surficiallayer, and the predominant period of microtremors.The most heavily damaged region is covered withabout 20-30 m. alluvium and the predominant periodis around 0.36 sec. The greatest destruction wasrecorded along a belt with the fault through the middleof the city, fig.1 (right of PL). However, to certaindistance heavy destruction was recorded on theshallow alluvium side.

Fig.1 Cross section south-north through the city center,ALT –alluvium terrace (gravel with send); PL –Pliocene (gravel, send with clay), conglomerates, marl);MPL – Mio-Pliocene (mostly marl)

On the left side of fig.1, along the slopes of themountain Vodno (1050 m), there are several remainsof the flow of the river Vardar. Vodno rises and thevalley sinks (witness of the intensive tectonicmovements in the old geology times). Over the rightside of fig.1 is the old town, soft soil proluvium andclay, with rare contemporary buildings in that time.Further north, 15-20 km is mountain, over 1000 mover see level; at the city center it is about 250 m.

The figures are drawn on the base of data gained byborings. Thousands of borings throughout the cityand around it, starting from about 6 meters deep, upto several hundreds, have given useful data, aboutthe geology of the ground and geotechnicalcharacteristics. In addition, by application ofgeophysical methods and seismic prospecting, thegeology up to thousands meters was obtained,including the velocity of the seismic waves. Furthermore, the micro tremor investigations were carriedout, according to the K.Kanai method.

The data gained by all of these investigationswere base for derivation of amplification coefficientsfor particular regions. The method of analysis wasthat of Kanai-Tanaka. The amplification distributiondetermined in that manner, in general, was similar tothe damage distribution. After the earthquake, in1964-65, series of after-shock measurements byseismographs were carried out, at several points withdifferent characteristic of the soil. The maximumamplification was 2.97 at point on 40 m. thickalluvium surficial layer. This is close to 20-30 m inthe most damaged region, fig.1, right of the fault.


50 22 - 24 January, 2011

(There were not records around these thicknesses).The main purpose of the last investigations wasseismic microsoning, but it seems not quit successful.Unfortunately, any micro-zoning did not take place.

Fig2 Longitudinal section west, north west – east, southeast through the center; at both ends- Faults, deepsinking, in the west more than 120m, in the east almost200 m., transverse faults at both ends also.

On small hills around the city, on the surfaceappears neogen (MPL), which is base-rock for bigportion of the valley, with dominant period of 0,36sec.This could be the dominant period of the incomingseismic waves, same as the period of the mostdamaged region. It means vibration close toresonance and big amplification of the vibrations onthe surface. In addition, there were many buildingsof 3-4 stories, with natural periods close to that one- destroyed. By analysis of several damagedbuildings, it was concluded that maximum seismicforces could have been equivalent to accelerationof 50-60%g.

In the case of greatest distraction around the faultat the middle of the city, fig.1, the left side withshallow alluvium, the dominant period is of the orderof 0.15 sec. The right side, of deep alluvium, hasdominant period of micro vibration of the order of0.36sec. So, there had to be like vibrations out offaze of two portions, or precisely spiking – shearforces occurred, and cutting of buildings.

On the portions of the city, at the ends of fig.2, therewere not many buildings and at that time not attentionwas given. But now, on the region east of the figure,many tall buildings are built, just over the faults. Inaddition, in progress is design of several very tallbuildings, minimum 150 meters high, on hundredsmeters thick, with water saturated alluvium!

Construction of buildings continues like nothing hashappen, the earthquake is forgotten. Nobody wantsto know about any investigation, even those whosejob it is supposed to be. A silly question arises: whatis the meaning of the research work by manyscientists? I am saying this because similar problemsmay be in many other countries.

S6_P1

Attenuation of Coda Waves of LocalEarthquakes In the Northeastern India

Alok Kumar Mohapatra(Email- [email protected] Tele: 9735636337)and William Kumar Mohanty (Department ofGeology and Geophysics, Indian Institute ofTechnology, Kharagpur, West Bengal, India. 721302.)

The attenuation of coda waves (Qc) have beenestimated for the Northeastern India, using ten localearthquakes from April 2001 to November 2002. Thesingle back scattering attenuation model is used toestimate frequency dependent values of Coda Q (Qc)at six central frequencies 1.5 Hz, 3.0 Hz, 6.0 Hz, 9.0Hz, 12.0 Hz, and 18.0 Hz. Earthquakes withmagnitude range from 3.8 to 4.9 have been takeninto account. These earthquakes are well recordedon the broad band seismic observatory atCherrapunji, Barapani and Bahiata in theNortheastern India. In the present work the Qc valueof local earthquakes are estimated to understand theattenuation characteristic and tectonic activity of theregion. Based on a criteria of homogeneity in thegeological characteristics and the constrains imposedby the distribution of available events the study regionhas been divided into three zones such as the TibetanPlateau Zone (TPZ), Bengal Alluvium and Arakan-Yuma Zone (BAZ), Sillong Plateau Zone (SPZ). Themean values of frequency-dependent coda Q varyingfrom 292.9 at 1.5 Hz to 4880.1 at 18 Hz. AverageQc value obtained by analysing coda waves of tenlocal earthquakes is 198 f 1.035. This relationshipvaries from the region to region such as, TibetanPlateau Zone (TPZ): Qc= 226 f 1.11, Bengal Alluviumand Arakan-Yuma Zone (BAZ) : Qc= 301 f 0.87,Sillong Plateau Zone (SPZ): Qc= 126 f 0.85. Theabove results indicates Northeastern India isseismicaly active but comparing of all zones in thestudy region the Shillong Plateau Zone (SPZ): Qc=126 f 0.85 is seismicaly most active. Where as theBengal Alluvium and Arakan-Yuma Zone (BAZ) areless active and out of three the Tibetan Plateau Zone(TPZ) is intermediate active. This study may beuseful to determine the source mechanism and theseismic hazard assessment.

Key words: Coda wave, Lapse time, singlebackscattering model and Northeastern India.

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S6_P2

Spectral Decay Parameter (κκκκκ) using theAccelerograms of the Earthquakes in Himalaya

Renu Yadav (E-mail: [email protected]),Kavita Rani, Gunjan Dhiman and Deepak Kumar(Department of Geophysics Kurukshetra UniversityKurukshetra 136 119 India)

It has been suggested that the spectrum of highfrequency strong ground motion from earthquakesis flat above the corner frequency to the maximumfrequency (fmax) after which the spectrum decaysfast (Hanks and McGuire, 1981). Anderson andHough (1984) suggested a model for the shape ofacceleration spectrum at high frequencies. Thismodel is characterized by spectral decay parameter– Kappa (κ). According to this model the fall off athigh frequency is related to the attenuation alongthe wave path and near the surface. The spectraldecay parameter has been used extensively tosimulate the earthquake strong ground motions. Ithas been found in some studies that high frequencyfall off have a source effect or it is combination ofnear surface attenuation and near surface effect.It has also been considered as related with recordingsite and earthquakes recorded.

The spectral decay parameter has been estimated inthe present study using the accelerograms of theearthquakes occurred in northwest and centralHimalaya. These events include 1986 Dharmsala, 1991Uttarkashi, 1999 Chamoli earthquakes and nine of itslarger aftershocks. The 42 accelerograms recorded atdifferent sites have been used in the present analysis.The values of κ found to be vary from 0.03s to 0.06sfor the Dahrmsala region. We note a increase in theκ values with increase in distance. The attenuation ofthe region has been analyzed by estimating κ atdifferent sites and source-station distances. Thepossible dependence of κ on site and earthquake sizehas also been investigated here. The estimated valuesof κ in this study is useful for the simulation ofearthquake strong ground motions and therefore forthe evaluation of seismic hazard in the region.

References

1. Anderson, J.G. & Hough, S.E. (1984) A modelfor the shape of the Fourier amplitude spectrumof acceleration at high frequencies, Bull. Seism.Soc. Am., 74, 1969-1993.

2. Hanks, T.C. & McGuire, R.K. (1981) Thecharacter of high frequency strong groundmotion, Bull. Seism. Soc. Am., 71, 2071-2095.

S6_P3

Estimation of Coda-Q using a Non-Linear(Gauss-Newton) regression

Savita Singh (E-mail: [email protected]),Sumedha, Monika Wadhawan and Vandana(Department of Geophysics, KurukshetraUniversity Kurukshetra 136 119 India)

The study of attenuation of seismic waves isimportant for the estimation of earthquake sourceparameters, to predict earthquake strong groundmotions and therefore useful in the evaluation ofseismic hazard of a region. The attenuation ofseismic wave is described by a parameter known asquality factor (Q). The Q can be estimated usingbody waves as well as coda-waves (Qc). Theestimation of coda-Q using local earthquakes hasbecome a routine exercise. The simplest method toestimate coda-Q is based on the single S to S backscattering model of Aki and Chouet (1975). Theusual way to estimate coda- Q using this to linearizethe equation of spectral amplitude of coda waves bytaking logarithms of both sides and then to use theleast square criterion. It has been suggested thatthe results of least square inversion on logtransformed data may be biased. Therefore a non-linear technique may be applied to estimate coda-Q.

A non-linear (Gauss-Newton) technique has beenused in the present study to estimate the Qc fromthe coda envelope without linearizing the equation.In this technique the model parameters (includingQc) are estimated iteratively by expanding therelationship around the model parameters using aTaylor series expansion. The technique has beendemonstrated on the waveforms of aftershocks of1999 Chamoli earthquake. The events recorded atGhat (GHA), Karanprayag (KPG), Pakhi (PAK),Gopeshwar (GPR) and Okhimath (OKI) have beenanalyzed. The Qc values have been estimated usingboth log-log as well as Gauss-Newton techniques.The initial values required in the Gauss-Newtontechnique have been obtained from log-log method.The preliminary results show that the values estimatedby Gauss-Newton method are lower that those oflog-log method. The results obtained using bothmethods have been compared and discussed.


52 22 - 24 January, 2011

S7_Keynote

Current trends in seismic instrumentation andearthquake monitoring in India

R.S. Dattatrayam, A.K.Bhatnagar, G.Suresh,P.R.Baidya, J.L.Gautam, H.P.Shukla andY.P.Singh (India Meteorological Department,Ministry of Earth Sciences, Lodi Road, NewDelhi-110003.)

The great Sumatra earthquake of 26th December,2004, the second largest mega thrust event everrecorded on the planet Earth, reiterated the need forreal time seismic monitoring for early warning oftsunamis. The Ministry of Earth Sciences (MoES)established a state-of-art Indian Tsunami EarlyWarning Center (ITEWC) at the Indian NationalCenter for Ocean Information Services (INCOIS),Hyderabad on 15th October, 2007. As part of thiseffort, a 17-station Real Time Seismic MonitoringNetwork (RTSMN) was set up by IndiaMeteorological Department (IMD), to monitor andreport, in least possible time, large magnitude under-sea earthquakes capable of generating tsunamis fromthe two known sources, viz., the Makran coast inthe north Arabian sea region and the Andaman-Nicobar-Sumatra island arc region. The groundmotion data from the 17 field stations is transmittedsimultaneously in real time through V-SAT

communication facilities to the two CRSs (CentralRecording Stations) located at IMD, New Delhi andINCOIS, Hyderabad for processing andinterpretation. To provide better azimuthal coveragefor locating earthquakes falling outside the coveragearea of the network, about 80 seismic stations ofIRIS (Incorporated Research Institutions forSeismology) Global Network have also beenconfigured in the RTSMN system. The CRSs areequipped with state-of-art computing hardware,communication, data processing, visualization anddissemination facilities. The RTSMN system makesuse of state-of-art auto-location software called,“Response Hydra (V-1.47)”, developed by NationalEarthquake Information Centre (NEIC), UnitedStates Geological Survey (USGS), for real timelocation of earthquakes. It provides fast, reliable andaccurate locations and magnitudes of world-wide,regional and local earthquakes. The final earthquakeinformation / products are disseminated throughvarious communication modes, such as, SMS, FAX,Email, IVRS and Website, to all the concerned useragencies in a fully automated mode. Based on theearthquake information provided by the RTSMNsystem and other ocean related observations /computations and analyses, INCOIS evaluates thetsunami-genic potential of the undersea earthquakesand issues necessary warnings / alerts as per

S7: Real Time Seismology, Early Warning and Loss AssessmentConveners : Friedemann Wenzel and R.S. Dattatrayam

THEMEThe aim of real-time seismology is to collect and analyze seismological data rapidly duringa seismic crisis and utilize them for developing information on hazard, potential damageof large events, actual damage, and aftershock risk, with the aim of mitigating theearthquake impact on human society. Before a main shock the focus is on providingindications for an impending event by time-dependent assessment of hazard and risk.During a shock alert and shake maps of ground shaking allow rapid assessment of theexpected area and scope of the earthquake; in many cases several seconds to a minutemight be available for early warning sensu stricto with options to shut down criticalfacilities, secure industrial facilities, and issue alarms where appropriate. After the mainshock rapid damage estimates based on seismological information and on a modeledstructural environment can be delivered to the emergency institutions. Also, the risksassociated with aftershocks can be assessed. Operational systems covering some of theaspects mentioned are meanwhile in place in Japan, Mexico, Taiwan, Europe and theU.S. The session will explore the state-of-the-art of this evolving technology and highlightapplication options in the Indian context.

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Standard Operating Procedures (SOP). TheResponse Hydra also provides real time CentroidMoment Tensor (CMT) and Moment Tensor (MT)solutions for earthquakes of magnitude rangingbetween 5.5-7.5 and 6.0-8.0 respectively, which alsohelps in the assessment of tsunami-genic potentialof undersea earthquakes. Various earthquakeproducts generated by the RTSMN system in realtime are depicted in Figure-1.

The RTSMN system is in successful operation formore than two years now and is providing real timeproducts on earthquakes in the region, which arecomparable to those generated by equivalent regionaland global networks such as, USGS, GEOFON andEMSC. The auto-location capabilities of the RTSMNsystem have been compared with those of USGSand it is seen that the performance is found to bevery satisfactory, particularly for large magnitudeearthquakes occurring in the region. The differencein the magnitudes estimated by the RTSMN systemand that of USGS are well within +0.2 units formajority of the events. Similarly, the epicentrallocations and focal depths of majority of the eventsare broadly in good agreement (within +20.0 km and+30.0 km. respectively) with those of USGS. Forearthquake events occurring well within the Indianlandmass, the RTSMN system has provided betterhypocentral estimates than other networks, asexpected. In terms of response time, it is seen that

the time taken for auto-location by RTSMN systemtypically varied between 3 minutes for an event inNepal on 8th December, 2008 (M:5.4 and Latitude:29.7 degree North and Longitude: 81.8 degree Eastand located using 17-station data alone) to 13 minutesfor an event in Java, Indonesia on 10th December,2008 (M:5.5 and Latitude: 7.1 degree South andLongitude:108.5 degree East). The paper presentsthe salient features of the RTSMN system, its

efficacy and performance vis-à-vis the other globalnetworks in operation for monitoring large magnitudeearthquakes in the region.

S7_I1

EDIM – Earthquake Disaster InformationSystem for the Marmara Region, Turkey

Wenzel, F.1; Erdik, M.6; Köhler, N.1; ZschauJ.2; Milkereit, C.2; Picozzi, M.2; Fischer, J.3;Redlich, J.3; Kühnlenz, F.3; Lichtblau, B.3,Eveslage, I.3; Christ, I.4; Lessing, R.4;Kiehle, C. 5(1Geophysical Institute, KarlsruherInstitute of Technology (KIT), E-mail:[email protected],2GeoForschungsZentrum (GFZ) Potsdam,3Computer Science Department, HumboldtUniversity Berlin, 4DELPHI IMM GmbH,Potsdam, 5lat/lon GmbH, Bonn ([email protected]), 6KOERI, Bogazici University, Istanbul)

Figure-1: Real time earthquake products generated by the RTSMN system.


54 22 - 24 January, 2011

The main objectives of EDIM (www.cedim.de/EDIM.php) are to enhance the Istanbul earthquakeearly warning (EEW) system with a number ofscientific and technological developments that – inthe end – provide a tool set for EEW with wideapplicability. Innovations focus on three areas. (1)Analysis and options for improvement of the currentsystem; (2) development of a new type of self-organising sensor system and its application to earlywarning; (3) development of a geoinformationinfrastructure and geoinformation system tuned toearly warning purposes. Development in the frameof the Istanbul system, set up and operated byKOERI, allows testing our novel methods andtechniques in an operational system environment andworking in a partnership with a long-standing traditonof success. EDIM is a consortium of KarlsruheUniversity (TH), GeoForschungsZentrum (GFZ)Potsdam, Humboldt University (HU) Berlin, lat/lonGmbH Bonn, DELPHI Informations MusterManagement GmbH Potsdam, and KandilliObservatory and Earthquake Research Institute(KOERI) of the Bogazici University in Istanbul. Theintegration of strong motion seismology, sensorsystem hard- and software development, andgeoinformation real-time management tools prove asuccessful concept in making seismic early warninga novel technology with high potential for scientificand technological innovation, disaster mitigation, andmany spin-offs for other fields. EDIM can serve asa model for further developments in the field of earlywarning on a global scale.

www.cedim.de/EDIM.php

S7_C1

Seismic loss Reduction/Estimation techniquefor use in Educational Spaces in Gujarat, India

Chandra Bhakuni (Managing Director,QuakeSchool Consulting Pvt. Ltd., Ahmedabad,India)

This paper proposes a risk assessment method forseismic protection of buildings by reducing the datainput quantity of structural engineering aspects, andseeks improved quality of results with a containableerror margin. We propose this as an improvedmethod towards building an effective risk mitigation

strategy, based on risk reduction principles whichestimate maximum probable damages. The techniquebecomes highly useful for a large infrastructure set– such as educational building infrastructure in alarger area.

We make use of the globally available groundaccelerations by Global Seismic Hazard AssessmentProgram (GSHAP), and have improved structuralvulnerability curves after the 2001 Gujaratearthquake, and identify building typology; amongstother few parameters. This leads to identification ofbuildings which have high seismic exposure, thusseismic ranking, coming into use to classify facilitiesbased on risk. As a fallout, the technique also helpsto identify non-structural parameters, and otheremergency planning aspects; which are useful indeveloping audit procedures and risk managementinformation systems in case of other emergencies.

If case of single building analysis the methodologyprovides conservative estimates due to absence oflarger input data, more accurate soil relatedparameters, and problems such as liquefaction.

S7_C2

The Seismic Alert System of Mexico(SASMEX)

Espinosa-Aranda J. M.(E-mail:[email protected]), Cuellar A. , GarcíaA., Ibarrola G.and Islas R. (Centro deInstrumentación y Registro Símico, A. C.)

The Mexico City and Oaxaca City authorities hasconvened the Seismic Alert System of Mexico City(SAS) and Seismic Alert System of Oaxaca City(SASO) integration development, both systemsinitially will conform the Seismic Alert System ofMexico (SASMEX), with a set of 48 sensing fieldstations, 17 radio relay stations. SAS started in 1991and covers the “Guerrero Gap” and SASO startedin 2003 and covers the seismic region of Oaxaca.They have emitted 78 early warnings of more than2350 earthquakes detected by their sensing fieldstations. SAS information is used in Acapulco andChilpancingo of Guerrero state by means ofAlternate Emitters of Seismic Alert System(EASAS) to send the early warnings like in Mexico

5522 - 24 January, 2011


City. This work describes both systems, the currentapplications like schools, subway, public officebuildings, emergency organizations, radio and TVcommercial broadcast, and recently the NWR-SAME receivers, etc., finally the general aspects ofSASMEX integration.

S7_C3

Early Warning System for Transportation Lines

E. Hohnecker1, A. Buchmann1, T. Titzschkau2,F. Wenzel2 , D. Hilbring3, G. Bonn3, F. Quante3(1Department of Railway Systems, Karlsruhe Instituteof Technology, Otto-Ammann-Platz 9, 76131Karlsruhe, Germany, E-mail:[email protected], 2Geophysical Institute,Karlsruhe Institute of Technology, Hertzstr. 16, 76187Karlsruhe, 3Fraunhofer Institute of Optronics,System Technologies and Image Exploitation,Fraunhoferstr.1, 76131 Karlsruhe, Germany)

Up to now, there are no earthquake early warningsystem applications that focus on the specificrequirements of transportation lines, with theexception of a Japanese system for railways thathas been developed since the 1980s. According toNakamura the UrEDAS (Urgent EarthquakeDetection and Alarm System) for railboundtransportation is worldwide the only early warningsystem for transportation lines in operation.

Recently, we have analyzed the potential of a newapproach to earthquake early warning for railwaysystems, called EWS TRANSPORT [1]. The principleof functionality of EWS TRANSPORT is realized in anonline demonstrator, publicly available under http://www.ews-transport.de. The demonstrator modelsand visualizes the entire early warning chain. Thisincludes earthquake early detection and real-time riskreduction measures for railway transportation beforeand during the strong motion phase as well as fastinfrastructure damage map generation after theevent.

Before and during the strong motion phase a riskreduction algorithm defines emergency measuressuch as stopping of a train or train speed reductionas a function of local peak ground acceleration(PGA), train velocity, and certain acceleration

thresholds based on experience made in Japan.

After the strong motion phase damage assessmentis performed for various railway infrastructureelements. For example, for railway bridges fivebridge damage classes (none, minor, moderate, major,complete) and the corresponding median PGA valuesare defined for various generic bridge constructiontypes.

Currently, these research results are represented inthe demonstrator with geospatial and railwayinfrastructure data bases from the federal state ofBaden-Württemberg in Germany as required dataare available to us for this region. However, ifcorresponding data from high seismicity areasbecome available, the results can be extended to suchcases.

References

[1] D. Hilbring et al., Natural Hazards, Springer, inpress (2010)

S7_C4

Seismo-Tectonic interpretations for the DelhiRegion Based on the Data Recorded at DelhiSeismic Array

Vivek Mahadev and Neelu Mathur (Delhi SeismicUnit, Seismology Division, BARC, New Delhi)

This case study is based on data recorded at DelhiSeismic Array (DSA) of BARC at New Delhi whichaims in identifying and characterising active faultsto evaluate seismic hazards in generally moderate-seismicity Delhi Region. Seismically active trijunctionof MDSSF, SDR and Aravalli Delhi Fold Belt regionsare generally characterised by low-hazard but high-risk, due to the concentration of human and materialproperties with high-vulnerability. Detecting tectonicdeformations that may lead to destructiveearthquakes in such areas requires innovativeresearch strategies and continuous monitoring ofslowly deforming faults due to man made changesand/ or natural tectonic movements. The paperhighlights the simple use of available visual aids tounderstand the correlation between seismicity andGeo-tectonic features.


56 22 - 24 January, 2011

S7_C5

Earthquake Vulnerability Assessment ofGujarat Port Sites Viz-a-viz SeismicDisturbances

Terala Srikanth1, Ajay Pratap Singh2, SumerChopra2, Ramancharla Pradeep kumar1 andB.K.Rastogi2 (1Earthquake Engineering ResearchCentre, IIIT Hyderabad, Gachibowli, Hyderabad-500 032, India. 2Institute of Seismological Research(ISR), Gandhinagar 382 009, Gujarat, India.

Gujarat State of India is a principal maritime stateendowed with strategic port locations. Kutch(Kachchh) region of the state was severely shakenby a powerful earthquake on 26 January 2001. Thisearthquake most seriously affected the Kandla portin addition to minor damages at other ports. Aboutfive of 10 jetties were damaged, reducing the berthingfacility at the port. There were severe damages tothe customs house, the administrative house, andcargo handling equipment. In this regard, there is aserious concern about the safety of port sites nearGujarat coast in view of seismic disturbances.

Most of the port structures were constructed beforethe seismic codes were developed. In light of thetremendous business and secondary losses associatedwith prolonged interruption of port operations, it isnecessary to check the vulnerability of coastalinstallation. For the purpose of study, four ports, viz.,Kandla, Pipavav, Mundra and Dholera are selected.These ports consist of a wide range of structuresand among which Jetty, conveyor belt, port buildingand buried pipelines that were selected for the study.At first, several earthquake scenarios will bedeveloped and seismic hazard due to each will beassessed. PGA maps, site specific response spectra,liquefaction potential maps will be prepared for eachearthquake scenario. Secondly, the performance ofthe structures will be evaluated by sophisticatednonlinear dynamic analysis. Since the structures arelocated on soil susceptible for liquefaction, oil-structure interaction effects will be considered in theanalysis.

S7_C6

Performance Analysis of Mundra PanipatPipeline Crossing Kachhach Mainland Fault

Vasudeo Govind Choudhary and RamancharlaPradeep Kumar (Earthquake EngineeringResearch Centre, IIIT Hyderabad, Gachibowli,Hyderabad 500 032, India.)

Gujarat has major pipeline network in the country,which is constantly spreading and will

boost up after dreamed Iran-Pakistan-India pipeline.Pipeline networks provide energy for generatingpower, transportation, produce necessary goods andservices to maintain a high quality of life in a modernsociety. Hence, pipelines are often referred to as“lifelines”. The wellbeing of community needs theselifeline systems to continue their function even underadverse situations. However, many pipelines in Indiarun through high seismic areas and are exposed toconsiderable seismic risk. Bhuj earthquake of 26 Jan2001 has already exposed several deficiencies indesign and construction the pipelines. In this regard,there is a serious concern about the performance ofpipeline during future earthquakes.

In this study, we are considering MundraPanipatpipeline crossing Kachchh Mainland Fault. Since theconsidered pipeline falls in zones III to V as perseismic hazard map, design requirement needs toconsider permanent ground displacement (PGD),uoyancy

due to liquefaction, fault crossing and seismic wavepropagation effects. At first we checked the safetyof considered pipeline using the analytical methodsuggested by IITKGSDMA guidelines and laternonlinear numerical analysis was employed to studythe capacity to pipeline for resisting the maximumdisplacement.

5722 - 24 January, 2011


S7_C7

Rapid Visual Survey of Existing Buildings inGandhidham and Adipur Cities, Kachchh,Gujarat

Terala Srikanth1, Ajay Pratap Singh2, SantoshKumar2, Ramancharla Pradeep kumar1 andB.K.Rastogi2 (1 Earthquake EngineeringResearch Centre, IIIT Hyderabad, Gachibowli,Hyderabad 500 032, India. 2Institute ofSeismological Research (ISR), Gandhinagar 382009, Gujarat, India)

Bhuj earthquake of 26 January 2001 caused 14,000casualties. Main reason for such huge casualties islow earthquake awareness and poor constructionpractices. Based on the technology advancement andknowledge gained after earthquake occurrences, theseismic code is usually revised. Last revision of IS1893 (Criteria for earthquake resistant design ofstructures) was done in 2002 after a long gap ofabout 18 years. Some new clauses were includedand some old provisions were updated. Assumingthat concerned authorities will take enough steps forcode compliance and the structures that are being

constructed are earthquake resistant. In this light,what will happen to the safety of precode revisionstructures? These structures carry major percentageof vulnerable structure stock. Even if we have avery good disaster response system, it is impossibleto reduce earthquake damage without consideringthe safety of precode revision structures. In thisregard, a comprehensive study of seismic riskassessment of Gujarat is necessary. As a pilot study,government of Gujarat selected Gandhidham andAdipur cities in Kachchh district.

Rapid Visual Screening (RVS) was conducted on16000 buildings in Gandhidham and Adipur cities.Though, there are varied construction practices,about 26% of buildings were predominantly RCCtype and 74% of masonry structure were found. RVSscore of these structures reveal that in generalbuildings are of low quality and further evaluationand strengthening of buildings is recommended. Theprocedure adopted in this study is threetier method,i.e., Tier 1. Rapid Visual Screening, Tier 2.Preliminary assessment and Tier 3. Detailedassessment.


58 22 - 24 January, 2011

S8_I1

The great Sumatra earthquakes: Results fromrecent marine studies

Satish C. Singh (Institut de Physique du Globe deParis, France (E-mail: [email protected]) andUniversity of Cambridge, UK)

The great earthquake of 26th December 2004offshore Sumatra was the second largestearthquake to have been recorded by modernsystems. It ruptured 1300 km of plate boundary overa 150 km-wide area from northern Sumatra all theway to the Andaman Islands. The tremor and thesubsequent tsunami caused massive devastation andloss of life. Three months later, another 8.7magnitude earthquake occurred on March 28 2005,300 km further south. On 12 September 2007, thethird great earthquake (Mw=8.5) occurred 1300 kmfurther south. There is a 600 km gap between the2005 and 2007, which is likely to break in the comingyears. During the 30th September 2009 earthquake(Mw=7.8) only a small fraction of energy wasreleased, which led to a death toll of over 2000,and a bigger earthquake is likely to occur in thenear future.

After the 2004 great earthquake, we have carriedout five marine studies, two of which were fundedby industry (Schlumberger and CGGVeritas, Singhet al., 2009). We have able to image the subductingplate from the seafloor 60 km depth. Here are someof the main results:

1. We find that downgoing oceanic crust is faulteddown to 30 km depth, which suggests that the2004 great earthquake might have ruptured amegathrust in the mantle (Singh et al., 2008).

2. The thrust in the mantle could be produced bythe change in the dip of the downgoing plate,leading to underplating of the oceanic crust anduplifting the Islands.

3. We have imaged a backthrust at 180 km fromthe subduction front in the 2004 earthquakeregion, which might have ruptured during thegreat earthquake and enhanced the tsunami inBanda Aceh (Chauhan et al, 2009).

4. We have also imaged backthrusts in the seismicgap region. If this backthrust ruptures co-seismically, it might lead to enhancement oftsunami and seismic risk to the SW of Sumatra(Singh et al., 2010).

5. We find that the reflectivity of the backthrust isbrighter in the 2004 and 2007 great earthquakeregions and weak in the locked zone, whichcould be due to the presence of fluid from themantle along re-activated backthrusts.

6. We have imaged a subducted seamount at 30-40 km depth and show that the presence ofseamount weakens the couple between thedowngoing plate and the overriding plate andcould be responsible for the earthquakesegmentation along the subduction zone.

I will discuss the above points using deep seismicreflection, refraction, earthquake, GPS and seafloorbathymetry data.

S8: Earthquake Ground Motions and Damaging EarthquakesConveners : Kojiro Irikura and Sumer Chopra

THEMEThe high amplitude ground motions near large earthquakes cause severe damage to lifeand property. The high frequencies present in a near field record are due to the complexitieson the fault surface and partly due to the scattering by inhomogeneities in the surroundingmedium. Therefore the strong motion data are very useful in the study of details of therupture process. The task is challenging for seismologists to study these near field recordsof damaging earthquakes which have occurred in the past and prepare models forpredicting future large earthquakes in potential areas with reasonable accuracy. A numberof techniques recently have been proposed to predict earthquake ground motions. Thesession aims at discussing latest techniques of predicting earthquake ground motionsand lessons learnt from past damaging earthquakes.

5922 - 24 January, 2011


Reference:

Singh, S.C., Hananto, H., Chauhan, A.P., Permana,H., Denolle, M., Hendriyana, A., Natawidjaja, D.(2010a). Seismic evidence of active backthrustingat the NE Margin of Mentawai Islands, SW Sumatra,Geophys. J. Int. 180, 703-714.

Singh, S.C., Midenet, S., Djajadihardja, Y. (2009).Seismic survey of the locked and unlocked Sumatrasubduction zone, EOS 90, 471-472.

Chauhan, A., Singh, S.C. et al. (2009). Seismicimaging of forearc backthrusts at northern Sumatrasubduction zone, Geophys. J. Int. 179, 1772-1780.

Singh, S.C., Carton, H., Tapponnier, P. et al. (2008).Seismic evidence of broken crust in the 2004Sumatra earthquake epicentral region, NatureGeosciences 1, 777-781.

S8_C1

Estimation of H/V ratio in different site innorthern Algeria with aftershock sequences ofBoumerdes earthquake

M.Mobarki (E-mail: [email protected]),M.Hamdache and A.Talbi. (Seismological Dept.Survey. CRAAG. BP 63 Bouzareah.16340Algiers-Algeria)

The recent seismic activity in northern Algeria,especially during the last 50 years, is characterizedby the occurrence of several damaging earthquakes.The EL Asnam region suffered the most destructiveand damaging earthquake recorded in NorthernAlgeria, namely those of September 9, 1954 (Ms 6.8)and October 10, 1980 (Mw 7.3). The most significantand recent event was the May 21, 2003 (Mw 6.9)Zemmouri earthquake, located at around 50 kmNortheast of Algiers. It is well established that theseismicity in northern Algeria is the result of thecompressional movement between African andEurasian plates. This seismicity is mainly located inTellian Atlas. In this context, the interest of thescientific community regarding seismology andseismotectonics has greatly increased in Algeria,especially in the fields related to the seismic riskassessment of urban seismic areas and its possiblereduction. The main task of this study is related tothe analysis of site effects observed during theseismic crisis generated by the Zemmouri

earthquake of 21 May 2003. We used the recordedaccelograms by temporary array of thirteen triaxialdigital accelerographs (Kinemetrics and Reftek)deployed in the epicenter area to monitor aftershocks.About 1000 events triggered this array during thethree-month deployment period. Based on siteresponse analyses of S waves and coda waves ofground motion recordings, both types of waves showthat the H/V ratios provide a good estimate at theresonant frequency.

In this study, we conducted an analysis of thereliability and applicability of the H/V ratio, usingthe popular Nakumura technique to determine theresonance frequency (fo) of amplification (Ao), wechose a high-quality data set covering the 2003Boumerdes earthquake sequences in order to identifysite effect in different area.

Key words: Nakumura, Amplification, resonancefrequency, site effect.

S8_C2

Ground motion parameters of Shillongplateau: One of the most seismically activezones of Northeastern India∗

Saurabh Baruah 1, Santanu Baruah 1 NabaKumar Gogoi 2 Olga Erteleva 3 FelixAptikaev 3 and J R Kayal 4(1 GeoscienceDivision, North-East Institute of Science andTechnology (CSIR), Jorhat-785006, Assam, India,2 National Geophysical Research Institute,Hyderabad-500 007, India, 3 Institute of Physics ofthe Earth, Moscow 123995, Russia, 4School ofOceanographic Studies, Jadavpur University,Kolkata 700032, India.

Strong ground motion parameters for Shillong plateauof northeastern India are examined. Empiricalrelations are obtained for main parameters of groundmotions as a function of earthquake magnitude, faulttype, source depth, velocity characterization ofmedium and distance. Correlation between groundmotion parameters and characteristics ofseismogenic zones are established. A newattenuation relation for peak ground acceleration isdeveloped, which predicts higher expected PGA inthe region. Parameters of strong motions, particularlythe predominant periods and duration of vibrations,depend on the morphology of the studied area. The


60 22 - 24 January, 2011

study measures low estimates of logarithmic widthin Shillong plateau. The attenuation relation estimatedfor pulse width critically indicates increased pulsewidth dependence on the logarithmic distance whichaccounts for geometrical spreading and anelasticattenuation. The peculiarities of ground motion onthe Shillong Plateau and its vicinity are considered.Obtained results allow to predict seismic treatmentdue to expected strong earthquakes and may becosidered as a basis for the seismic hazardassessment in the region under investigation.

S8_C3

Characterization of seismic regime in NWHimalaya: Persistent and high seismicity in theepicenter zone of great 1905 Kangraearthquake

Naresh Kumar*, B. R. Arora, D. K. Yadavand V. M. Choubey (Wadia Institute ofHimalayan Geology, 33 GMS Road, Dehradun –248001 India)

We attempted to quantify the seismic regime of NWHimalaya (26ºN-34ºN and 74ºE-82ºE) through spacetime distribution of seismicity from historical time(1550) to recent time. Recent M7.6 Kashmirearthquake of 8th October, 2005 and the great Kangraearthquake of 1905 have caused a heavy loss of lifeand property in this region. Although the availableseismological data has limited historical records andmagnitude range, the evidence of major (M>6)earthquakes during last five centuries, indicates thatthis region has been repeatedly fractured andaffected by major events. Most of the events areconfined to a narrow belt between surface trace ofthe Main Central Thrust (MCT) and Main BoundaryThrust (MBT). The regionalizations of seismicdeformation divide whole seismic belt into sub-areawith homogeneous seismic regimes. Space-timedistribution of seismicity (mainly post 1965) revealshighly heterogeneous segmentation with well definedsections of high seismicity centered on Kangra-Chamba, Kinnaur, Garhwal and Dharchula regions.This picture become more apparent in the post 1999period when the minimum detection threshold ofearthquake further reduced to M=2.5 followingaddition of new local seismic stations.

Kangra-Chamba region (epicenter zone of 1905 great

Kangra earthquake) is by far the most seismicallyactive area, with persistent shallow focused clusteredseismicity in a very confined focal volume withmajority of compressive regime. Persistent highseismic zone is evident by the clustering of epicentersand energy released irrespective of the duration andperiod of records examined. The recent seismic datathrough dense local seismic network indicatepredominant compressive regime in the southern andcentral part, limited localised extensional regimes inthe northern part and intermediate depth, and alsostrike-slip dominant deformation in the eastern partof 1905 Kangra earthquake.

S8_C4

Strong Ground Motion Simulation of the 2001/01/26 Bhuj, India Earthquake

Tao-Ming Chang (National Center for EarthquakeEngineering Research, Taipei, Taiwan

E-mail: [email protected])

During the 2001/01/26 Bhuj earthquake sequence,global seismic network only record one main shockand one aftershock. Inside the earthquake affectedzone, no modern digital strong motion records forthe main shock has been recorded. Thereforesynthetic acceleration seismograms are necessaryfor many other researches such as hazard analysis,earthquake loss estimations and earthquakeengineering studies.

In 2001/01/28 a Mw5.7 aftershock happen with verysimilar focal mechanism to main shock. Since theseismic moment energy ratio for main shock andafter shock is 657. Therefore in this study we useempirical Green’s function technique to calculate thesource time function for several different stations.Then perform a search to find a rupture process forthe Bhuj main shock. Also a second method used inthis study to estimate main shock rupture processby using Genetic algorithm to match teleseismic P-wave waveforms. These two processes arecompared.

Finally, we use wavenumber integration method tocalculate synthetic seismograms for different parton the rupture plane for different distances andassemble them as a complete synthetic accelerationseismograms to different locations. A seismic

6122 - 24 January, 2011


intensity map for Bhuj earthquake can be obtained.Many synthetic seismograms can be provided forother researches.

S8_C5

Recipe for Predicting Strong Ground Motionsfor Inland Mega Fault Earthquakes

Kojiro IRIKURA (Aichi Institute of Technology& Kyoto University, 1247 Yachigusa, Yakusa,Toyota, Aichi 470-0392, Japan)Susumu KRAHASHI(Disaster PreventionResearch Center, Aichi Institute of Technology)

From recent developments of the waveforminversion of strong motion data used to estimate therupture process, we found that strong ground motionis primarily related to the slip heterogeneity insidethe source rather than average slip in the entirerupture area. Asperities are characterized as regionsthat have large slip relative to the average slip onthe rupture area. There are two scaling relations,one between rupture areas and seismic moments,and the other between asperity areas inside therupture area and seismic moment. We developed a“recipe” for predicting strong ground motions fromspecific faults based on those two scaling relationsbetween fault parameters and seismic moments.Then, strong ground motions from specific faults areestimated using the characterized source modelbased on the recipe and numerical and empiricalGreen’s functions. However, the data have beenlimited to intermediate-sized earthquakes less theMw 7. Therefore, verification and applicability ofthe “recipe” also have been made using observedground motions from recent disastrous inland-crustal-earthquakes less than Mw7.In this study, weexamined the scaling relations for mega-fault systemsusing 11 earthquakes (Mw 7 70 8) of which sourceprocesses were analyzed by waveform inversion andof which surface information was investigated. Wefound that maximum displacement of surface rupturesaturates at 10m when fault length(L) is beyond100km, L>100km. Based on the above results, wedevelop three-stages scaling model between rupturearea and seismic moment as the scaling relation forouter fault parameters. We also examined the scalingrelations concerning asperity areas and stress drops,combined with the relations between acceleration

source spectral-levels and seismic moments. Weattempt to validate the characterized source modelfor simulating strong ground motions during the 2008Wenchuan earthquake of Mw 7.9 as an example ofthe inland mega-fault earthquakes.

S8_C6

Estimation of damage to various types ofbuildings in Gujarat from a future largeearthquake

Sumer Chopra (E-mail: [email protected]),Dinesh Kumar and B.K.Rastogi (Institute ofSeismological Research, Gandhinagar- 382009)

The Gujarat state has witnessed the disaster during2001 Bhuj earthquake. In order to prepare andprevent for such disasters from future largeearthquakes in Gujarat, we have estimated thedamage to various types of buildings. The peakground accelerations at important towns of Gujaratfrom future large earthquakes are estimated bydeterministic seismic hazard analysis taking intoaccount the source, path and site effects specificfor the site. A vulnerability function, developed byArya (2000), has been used for the estimation ofbuilding loss. The building data of the cities/talukashas been taken from 2001 census of Gujarat for thispurpose. According to this census the buildings inGujarat are broadly classified into three types basedon materials used in walls. The average loss ratio inpercent has been calculated for various buildingclasses using maximum intensity obtained in thatregion. Based on this, the number of buildings likelyto be damaged in a taluka/city is estimated. A totalof 3.7 lakh houses in Kachchh district are vulnerableto total damage in case of a large earthquake of M> 7.5 in Kachchh. In Saurashtra, most vulnerabletalukas are Rajkot, Jamnagar, Surendranagar, Morbi,Junagadh and Dwarka where 3.2 lakh buildings arelikely to be affected during a severe earthquake. Thebuildings in Radhanpur and Bharuch talukas inmainland are most vulnerable due to their proximityto active regions. In Ahmedabad, 25,000 five-storeyand 1500 eleven-storey buildings are vulnerable todamage from a future large earthquake in Kachchhand are at highest risk if they have not been designedtaking into account the earthquake forces.


62 22 - 24 January, 2011

S8_C7

Strong motion simulation of Great earthquakein the central seismic gap region of UttarakhandHimalaya

Kapil Mohan (Institute of SeismologicalResearch, Next to Petroleum university, Raisan,Gandhinagar,Gujarat (India)-382009;E-mail: kapil_geo@ yahoo.co.in),A. Joshi (Department of Earth science, IndianInstitute of Technology (IIT), Roorkee, India)

Uttarakhand Himalaya in India lies in the centralseismic gap region identified by Khattri and Tyagi(1983). Most of the area in Uttarakhand state hasbeen placed under zone V and zone IV of the seismichazard map published by Bureau of Indian standard,Govt. of India (BIS,2000). Some of the thrust/faultsin the region manifest evidence of neotectonics andrecurrent seismicity (Valdiya and Pant, 1986; Valdiya,1999; Thakur; 2004; Paul et al., 2004). On the basisof strain accumulation, Bilham et al. (2001) suggesteda magnitude M>8 earthquake in this region. In thepresent work a great earthquake along Main CentralThrust in the central seismic gap region has beenmodeled using semi empirical technique of Joshi andMohan (2008). The shear wave quality factor usedfor modeling strong ground motions is computedusing the database of strong motion earthquakesrecorded by a local network in Kumaon Himalayausing the method of damped least square inversion.A total S phases of 27 strong motion records fromsix stations have been used for this inversion. Anaverage relation in the form Qâ(f) = 30f1.45 has beenobtained for Pithoragarh region of Kumaon Himalaya(Joshi et al., 2010). The strong motion parameters(Peak ground acceleration (PGA), Spectralacceleration and normalized spectral acceleration)are computed at five stations (Sobla, Didihat,Munsiari, Dharchula and Pithoragarh) in UttarakhandHimalaya. The maximum PGA of ‘2g’ is calculatedat Sobla station that is located in the down dip sideof the rupture plane and minimum PGA (0.15g) atPithrogarh station. The spectral acceleration is alsocomputed on all five stations at T= 0.4s, T= 0.75sand T= 1.25s. The maximum spectral accelerationin all three periods is highest at Sobla station. In otherfour stations the spectral acceleration varies from0.18g to 1.44g (at 0.4s), 0.11g to 0.85g (at 0.75s)

and 0.06g to 0.48g (at 1.25s). The normalized spectralacceleration (Sa/g) is also calculated at all fivestations. It varies from 0.62g to 2.01g (at 0.4s), 0.30gto 1.8g (at .75s) and 0.18 to 0.72(at 1.25s). Thistype of study is quite helpful for seismic resistantdesigns in earthquake prone areas and to assess thedamage potential of various types of buildings dueto an earthquake in the vicinity.

Keywords: Seismic gap, great earthquake, peakground acceleration, peak spectral acceleration,normalized spectra.

S8_P1

Attenuation relations for the Kumaon andGarhwal Himalaya, Uttarakhand, India

Joshi and A. Kumar(Department of EarthScience, Indian Institute of Technology Roorkee,Roorkee, India.),A. Sinvhal (Department of EarthquakeEngineering, Indian Institute of TechnologyRoorkee, Roorkee, India.)

Uttarakhand Himalaya is among most seismicallyactive regimes of the world. The whole region isdivided into two major parts i.e. Garhwal Himalayaand Kumaon Himalaya. For Himalayan region veryfew attenuation relations have been developed whichcan be applied to the different parts of Himalayaseparately. In Himalayan region limited availabilityof sufficient strong motion dataset pose difficulty forobtaining attenuation relations which are applicablefor different region within entire Himalaya. Usinglimited data sets two attenuation relations have beenprepared for Garhwal Himalaya and KumaonHimalaya, respectively. Strong motion data from anetwork strong ground motion recorders operatingin the Kumaon Himalaya between 2006 to 2008 hasbeen used as input to develop regression relation.For developing regression relation for KumaonHimalaya one hundred fifty one strong motionrecords have been as an input in the regression study.The data set cover the magnitude and hypocentralranges between 3.5 d” Mw d”5.3 and 10 d” R d”100 km, respectively. Peak ground acceleration fromstrong motion records from a strong motion arraydeployed in Garhwal Himalaya has been used forprepared regression relation for Garhwal Himalaya.Twenty nine strong motion records from a network

6322 - 24 January, 2011


operating in Garhwal region has been used as inputto regression study. Strong motion data from GarhwalHimalaya have been downloaded from websitedeveloped and maintained by the DepartmentEarthquake Engineering Indian Institute ofTechnology Roorkee. The data set cover themagnitude and hypocentral distance ranges between3.7 d” Mw d” 5.3 and 20 d” R d” 213 km,respectively. Following two regression relations hasbeen obtained for Garhwal and Kumaon Himalaya,respectively in this work:

For Kumaon Himalaya:

Log (PGA) = -6.17 + 2.04 Mw - .019 R -.45 log (R+15)

For Garhwal Himalaya:

Log (PGA) = -4.17 + 1.96 Mw - .012 R -.38 log (R+15)

Where peak ground acceleration (PGA) is in gal,Mw is moment magnitude and R is hypocentraldistance in km, respectively. The fit of regressionwith observed data confirm the utility of developedregression.

S8_P2

Prediction of Strong ground motion in theCoastal and Economically Important Regionsof Gujarat using Deterministic Seismic HazardModel

Kapil Mohan (Institute of SeismologicalResearch, Gandhinagar, Gujarat (India)-382009.Email: [email protected])

The expected peak ground acceleration at fifteenstations in the coastal region of Gujarat are estimatedusing semi empirical approach (Joshi et al., 2001;Joshi and Midorikawa, 2004) at B/C boundaryNEHRP level. The semi empirical technique issimilar to empirical green function (EGF) techniqueof Irikura (1986) however the requirement ofaftershocks is replaced by simulated time serieshaving envelope of accelerograms in time domainand spectral contents of high frequencyaccelerograms in the frequency domain. This method

follows omega square decay at high frequencies,directivity effects and other strong motion properties.To estimate the maximum possible damage, anearthquake of magnitude Mw 7.6 along the centralpart of Kachchh Mainland Fault (KMF) (ScenarioI) and magnitude Mw 7.5 along eastern part of KatrolHill Fault (KHF) (scenario II) is considered in thisstudy. The attenuation characteristic of EasternNorth America (ENA) matches with the Kachchhregion of Gujarat (Cramer and Kumar, 2003). Theattenuation relationships of Toro et al., 1997, Atkinsonand Boore, 1995 (after applying corrections for B/Csite suggested by Frankel et al., 1996), Frankel etal., 1996 and Somerville et al., 2001 of ENA andIyengar and Raghukanth (2004) and Mandal et al.,2009 of western central region (Peninsular India)and Kachchh region of Gujarat, respectively at B/Csite are tested with the Structural Response Recorder(SRR) data and strong motion data of 2001, Bhujearthquake. The 2001, Bhuj earthquake datacorrelated best with Atkinson and Boore (1995). Theroot mean square error (RMSE) of Toro et al., 1997(after applying correction for B/C site) and 2001,Bhuj earthquake recorded data was found the least.The average of Atkinson and Boore (1995), Toro etal., 1997 of ENA and Mandal et al., 2009 of Kachchhhas been considered in the present study to estimatethe expected peak ground acceleration.

The maximum peak ground acceleration (PGA)of 290 cm/sec2 is calculated at Kandla due toScenario I whereas the maximum PGA of 264cm/sec2 is calculated at Mandvi due to scenario II. Themaximum PGA of 22 cm/sec2 and 12 cm/semc2 iscalculated at commercially important Dholera andBharuch special economic zone (SEZ), respectivelydue to Scenario I. The maximum PGA difference(156 cm/sec2) due to both scenarios is found atMandvi whereas the minimum PGA difference (0.6cm/sec2) is found at Talala station.

Keywords: strong motion simulation, semi empiricaltechnique, NEHRP B/C boundary, peak groundacceleration.


64 22 - 24 January, 2011

S9_I1

Seismic Hazard Assessment for Gandhidham;Kutch; Gujarat

Fumio Kaneko1 (E-mail: [email protected]),Michio Morino1 (E-mail: [email protected]),Shukyo Segawa1 (E-mail : [email protected]),Jun Matsuo1 (E-mail: [email protected]),Koichi Hasegawa1 (E-mail : [email protected]),

Javed Malik2 (E-mail: [email protected]), andSushil Gupta3 (E-mail address:[email protected]) (1OYO InternationalCorporation, 2Indian Institute of TechnologyKanpur, 3RMSI Private Limited)

Comprehensive seismic hazard assessment wasconducted for Gandhidham area including Anjar city.Allah Bund Fault (ABF), Island Belt Fault (IBF),Kutch Mainland Fault (KMF) and Bhuj - Katrol HillFault (BF and KHF) are selected as the scenarioearthquakes. The trench survey was conducted andrevealed that KMF, KHF and BF are indeed active.80 drilling and 16 PS loggings are conducted at thesite. It was confirmed that Vs and N-value has goodrelation in this area as in other region. The surfaceground of the study area was modeled for every250m sq. grids up to engineering seismic bedrock.The subsurface amplification is evaluated by

empirical amplification factor from AVS30 and siteresponse analysis, and they show good relation.

In conducting this study, following points are foundto be improved for future hazard assessment studyin India; 1) Shallow ground condition should bestudied more. Actual S-wave velocity should besurveyed. 2) Seismic source research work includingactive fault trench study and paleo-seismic study arenecessary. 3) All the data relating hazard assessmentshould be open to the researchers and engineers.

S9_I2

Seismic Hazard Assessment based on UnifiedScaling Law for Earthquakes

Anastasia K. Nekrasova(International Instituteof Earthquake Prediction Theory andMathematical Geophysics, Russian Academy ofSciences, 84/32 Profsoyuznaya Street, Moscow117997, Russian Federation);Vladimir G. Kossobokov(International Instituteof Earthquake Prediction Theory andMathematical Geophysics, Russian Academy ofSciences, 84/32 Profsoyuznaya Street, Moscow117997, Russian Federation; Institut de Physiquedu Globe de Paris, Paris, France. E-mail:[email protected])

S9: Seismic Hazard Assessment/MicrozonationConveners : A. Peresan, Fumio Kaneko, T.G. Sitharam and Imtiyaz Parvez

THEMEDevelopment of effective mitigation strategies requires sound seismic microzonation andseismic hazard information. The purpose of seismic hazard assessment (SHA) is to providea scientifically consistent estimate of seismic hazard for engineering design and otherconsiderations. The time is ripe to move beyond traditional Probabilistic Seismic HazardAssessment, because it is not based on earthquake sciences (i.e., invalid earthquakesource model, misuse of statistics, and invalid mathematics). PSHA practice has becomethe “old good paradigms” of widespread ignorance and intolerance to any revision.Although there are many approaches available for SHA, this Session advocates theadvanced methods for seismic hazard assessment and seismic microzonation that utilizeup to date earthquake science and basic scientific principles to derive the seismic hazardin terms of a ground motion or related quantity and its occurrence frequency at a site, aswell as the associated uncertainty.

The Session is addressed to seismologists, engineers and stake-holders, and aims tocontribute bridging modern interdisciplinary research and end-users, who have to copewith the problems of the earthquake risk management and natural disasters preparedness.

6522 - 24 January, 2011


There is growing stream of the best documentedinstrumental observations that evidently contradictto generally accepted models of seismic hazardassessment. Many of the “fatal assumptions”attributed to seismic activity are misleading tounacceptable surprises like the 2001 Bhuj and 2008Wenchuan great earthquakes and the most recent2010 Haiti major earthquake disaster. Therefore, themodel assumptions require a prompt serious revision.We suggest making use of the fact that earthquakelocations have heterogeneous, possibly, fractaldistribution in space (at scales from hundreds km toa few km or less), which implies systematicunderestimation by traditional methodologies ofseismic hazard for cities and urban agglomerations.The confirmed patterns of distributed seismic activityfollow the Unified Scaling Law that generalizesGutenberg-Richter recurrence relation as follows:Log N(M,L) = A - B (M - 5) + C Log L, whereN(M,L) is the expected annual number ofearthquakes of magnitude M within an epicenterprone locus of liner size L. For a wide range of controlparameter A from under -1.0 to above 0.5 (whichvalue determines the average rate of magnitude 5earthquakes and, accordingly, differs by a factor of30 or more), the balance between magnitude ranges,B, resides mainly from 0.6 to 1.1, while the fractaldimension of the local epicenter prone setting, C,changes from under 1 to 1.4 and larger. Theunderestimation of earthquake recurrence rate ontransition from the territory of linear size L to theterritory of linear size l equals (l/L)C - 2 when scaleddown by traditional proportion to the area of interest.

Stabilized version of a robust box-counting algorithmSCE (Scaling Coefficients Estimation) was appliedto map the reliable values of A, B, and C worldwide.These basic characteristics of earthquake distributionthe recurrence rates of moderate, strong, major, andgreat maps in terms of the maximum of expectedintensity in 30, 50 and 100 years at the 10 % level ofprobability of exceedance. The results are comparedto traditionally scaled estimates based on theobserved recurrence rates in the extendedneighborhoods of a city, as well as to traditionalseismic hazard maps (GSHAP). The general levelof underestimation of the rates is too large for beingignored in seismic risk and earthquake loss

evaluations necessary for a knowledgeable disasterprevention and mitigation. Earthquakes are estimatedin seismically active regions and, in particular, forcities and urban agglomerations, then used to providea seismic hazard.

S9_I3

Neo-Deterministic Seismic Hazard Techniques– Contributions to the AlternativeRepresentation of the Seismic Loading forBulgaria.

Kouteva M.1, Paskaleva I.1, Vaccari F.2,3,Romanelli F. 2,3, Panza G.F. 2,3 (1NIGGG-BAS,Sofia, Bulgaria, E-mail: [email protected], 2 DiGeo-UTS, Trieste, Italy; 3 SAND-ESP,ICTP, Trieste, Italy)

The new legislation about the earthquake engineeringdesign and practice in Europe, Eurocode 8 (EC8),deals with the necessity of using alternativerepresentation of the seismic input, e.g.accelerograms, for the non linear structural analysesof complex, irregular and/or important structures inseismic regions. Generally there are two approachesfor the representation of the seismic input: (1) realrecorded acceletrograms or (2) theoreticallycomputed seismic signals. The use of realacceleration records requires comprehensiverepresentative database of reliable data varying inepicentral distance, local site conditions and seismicsource characteristics. Despite of the growing strongmotion registration networks in Europe, the existingdatabase is still not complete with regard to thisvariety and the lack of completeness will last formany years if not centuries. Therefore it is necessaryto look for reliable methods, based on physical andmathematical models, used for seismic inputdefinition via seismic waves propagation modelling.During the last decade, due to the lack ofrepresentative instrumental data in Bulgaria, ourattention has been concentrated on exploring forphysically and scenario based methods for SHA,going beyond the classical PSHA shortcomings, welldocumented by Kobe (17.1.1995), Gujarat(26.1.2001), Boumerdes (21.5.2003) Bam(26.12.2003), E-Sichuan (12.5.2008) and Haiti(12.1.2010) events, and its deficiency to supplyrealistic accelerograms as alternative seismic input


66 22 - 24 January, 2011

representations. Thus the neo-deterministic method(NDSHA) developed at the Department ofGeosciences, University of Trieste, has been usedfor seismic hazard assessment at different scales inBulgaria – regional, national and urban. The majorproblem has been to couple the effect of both,shallow local and intermediate-depth Vrancea,seismic effects on the Bulgarian territory for designpurposes. The large-scale application at regional andnational level made it possible to shape a proposalfor a zone within NE Bulgaria, in which the decisiveVrancea contribution requires to perform engineeringstructural analyses using two elastic spectral shapes,local and Vrancea ones.

S9_I4

Neo-Deterministic Seismic Hazard and PatternRecognition Techniques: Time-DependentScenarios for North-Eastern Italy.

A. Peresan1, 2, E. Zuccolo3, F. Vaccari1, 2, A.Gorshkov2, 4 and G. F. Panza1, 2(1 Department ofEarth Sciences, University of Trieste, via E. Weiss1, 34127 Trieste, Italy. E-mail: [email protected] ,2

The Abdus Salam International Centre forTheoretical Physics, ICTP, 34100 Trieste,Miramare, Italy., 3EUCENTRE - European Centrefor Training and Research in EarthquakeEngineering, Via Ferrata, 1 - 27100 Pavia – Italy.,4 International Institute of Earthquake PredictionTheory and Mathematical Geophysics, RussianAcademy of Sciences, Warshavskoe sh.79, kor.2,Moscow.

An integrated neo-deterministic approach to seismichazard assessment has been developed thatcombines different pattern recognition techniques,designed for the space–time identification ofimpending strong earthquakes, with algorithms forthe realistic modeling of seismic ground motion. Theintegrated approach allows for a time-dependentdefinition of the seismic input, through the routineupdating of earthquake predictions and by means offull waveform modeling. A set of neo-deterministicscenarios is defined at regional and local scales, thusproviding a prioritization tool for timely preparednessand mitigation actions. Constraints about the spaceand time of occurrence of the impending strong

earthquakes are provided by three formally definedand globally tested algorithms, developed accordingto a pattern recognition scheme. Two algorithms,namely CN and M8, are routinely used forintermediate-term middle-range earthquakepredictions, while the third algorithm does not belongto the family of earthquake prediction algorithmssince it allows for the identification of the areas proneto large events. These independent procedures havebeen combined to constrain the alarmed area. Italyis the only region where the two different predictionalgorithms, CN and M8S (i.e. a spatially stabilizedvariant of M8), are applied simultaneously and a real-time test of predictions, for earthquakes withmagnitude larger than a given threshold (namely 5.4and 5.6 for CN algorithm, and 5.5 for M8S algorithm)has been ongoing since 2003. Neodeterministicscenarios are provided, at regional and local scaleand for the cities of Trieste and Nimis (Friuli VeneziaGiulia region), where the knowledge of the localgeological conditions permitted a detailed evaluationof the expected ground motion.

S9_I5

Ground Motion at bedrock level in Delhi Cityfrom different earthquake scenarios\

Imtiyaz A Parvez1, Fabio Romanelli2 andGiuliano F Panza2,3 ( 1CSIR Centre forMathematical Modelling and Computer Simulation(C-MMACS), NAL Belur Campus, Bangalore, India,2 Department of Earth Sciences, University of Trieste,Trieste, Italy. 3The Abdus Salam International Centrefor Theoretical Physics, Trieste, Italy)

Delhi, the capital of India, is prone to severe seismichazards, not only from local events but also fromHimalayan earthquakes at distances of 250–300 km.Standard techniques are not sufficiently reliable tocompletely characterize the seismic hazards in thiscase due to the difficulty of predicting the occurrenceof earthquakes (frequency–magnitude relations) andof properly treating the propagation of their effects(attenuation laws), especially their long-periodcomponents. In order to give a sound description ofthe seismic ground motion due to an earthquake insuch a given range of distances (and magnitudes),we use modeling techniques developed from physics

6722 - 24 January, 2011


of the seismic source generation and propagationprocesses. Such models take into account thedirectivity effect of rupture propagation and theattenuation of (long-period) ground motions. Thegenerated ground motion scenarios permit us to builda very important knowledge base to be fruitfully usedby civil engineers, since long period ground motions,especially if amplified by deep sedimentary basins,can represent a severe threat for large scalestructures (e.g. lifelines and bridges) and tall buildings,which are widespread in fast-growing megacities.In this study, we simulate the ground motion, atbedrock level, in Delhi city, for two earthquakescenarios corresponding to a source of Mw = 8.0located in the central seismic gap of Himalayas, atan epicentral distance of about 300 km and a regionalearthquake scenario at a distance of 175 km fromDelhi. By means of several parametric studies, wesimulate the time histories using Size Scaled PointSource, Space and Time Scaled Point Source andExtended Source models.

Together with the complete time histories(displacements, velocities and accelerations, fromwhich the peak amplitudes have been extracted),we have also used the displacement responsespectrum to characterize the seismic input at Delhi.Not only is the displacement response spectrum ofgreat significance to modern displacement-baseddesign engineering approaches, but it is probably thebest parameter by which to characterize thedestructiveness potential of earthquakes located atsuch great distances from the target sites (of theorder of 300 km), since the energy of the seismicinput is mainly concentrated at long periods (ingeneral, greater than 1 s) and it cannot be determinedby straight forward integration of velocity oracceleration response spectra.

S9_I6

Robabilistic Seismic Hazard Macrozonation ofIndiaT.G. Sitharam (E-mail: [email protected]),Sreevalsa Kolathayar and K.S. Vipin(Department of Civil Engineering, Indian Instituteof Science, Bangalore – 560012)

In view of the major advancement made inunderstanding the seismicity and seismotectonics of

India during the last two decades, an updatedprobabilistic seismic hazard map of India covering6°–38N and 68°–98°E was prepared and presentedin this paper. The earthquake catalogue wasprepared by compiling the data from various nationaland international agencies. Homogenization ofdifferent magnitude scales to Moment magnitudewas done and the catalog was declustered to removethe dependent events. A total of 51347 earthquakesof moment magnitude 4 and above were obtainedfrom the study area after declustering, and wereconsidered for further analysis. The sesismotectonicmap of the study area was prepared by consideringthe faults, lineaments and the shear zones in the studyarea (SEISAT, 2000) which are associated withearthquakes of magnitude 4 and above.

In probabilistic seismic hazard analysis (PSHA), theevaluation of PGA was done by considering theuncertainties involved in the earthquake occurrenceprocess. The uncertainties in earthquake recurrencerate, hypocentral location and attenuationcharacteristics were considered in this study. Forassessing the seismic hazard, the study area wasdivided into small grids of size 0.1°×0.1°, and thehazard parameters were calculated at the centre ofeach of these grid cells by considering all the seismicsources within a radius of 300 km. A logic treeapproach, using two types of sources and differentattenuation relations, was adopted for the evaluationof PGA values. The contour maps showing spatialvariation of PGA value at rock level are presentedin the paper.

Keywords: Probabilistic Seismic Hazard Assessment,Attenuation relations, Peak Ground Acceleration

S9-I7

Study of the Local Site Effects on SeismicHazard Using Deterministic and ProbabilisticApproaches: A Case Study of Karnataka StateBy

T.G. Sitharam (E-mail: [email protected]);Sreevalsa Kolathayar and K.S. Vipin(Department of Civil Engineering, Indian Instituteof Science, Bangalore – 560012)

Earthquakes hazards are one of the worst naturaldisasters, causing huge loss to human life and


68 22 - 24 January, 2011

manmade structures. It is impossible to prevent theearthquake from occurring so for mitigating its effect,a proper hazard study is required. Major seismichazards causing extensive damages are groundshaking and liquefaction. These hazards depend uponthe geotechnical properties of the soil overlying thebedrock as the characteristics of ground motion likeamplitude, frequency and duration changes when theseismic waves travel from bed rock to groundsurface and this phenomenon is termed as local siteeffect. The study of this variation is very importantfor shallow founded structures, geotechnicalstructures like retaining walls and dams, floating pilesand underground structures as these are veryvulnerable to above mentioned hazards. In this paper,the peak ground acceleration (PGA) at the groundsurface was evaluated for the state of Karnataka.Karnataka is a state in the Peninsular India,tectonically forming the intraplate region of Indianplate. Major earthquakes like Bellary (Mw 5.7 in1843), Coimbatore (6.3 Mw in 1900), Koyna (Mw6.1 in 1967), Hassan (Mw 5.6 in 1970) and Latur(Mw 6.1 in 1993) showed that the region hasreasonably high seismicity compared to other shieldregions and hence the hazard assessment for thestate is very necessary. In order to estimate PGA atground surface, the hazard at the bedrock level wasestimated first by deterministic and probabilisticapproaches incorporating logic tree methodologyconsidering events and earthquake sources within300km from the boundary Karnataka. The state ofKarnataka was divided into a grid size of 0.05° x0.05o and a MATLAB program was employed forboth deterministic and probabilistic analysis usingthree attenuation relations proposed by Raghukanthand Iyengar (2007), Atkinson and Boore (2006) andToro et.al, (1997). By assuming the soil above bedrock of the whole region belonging to site classes Ato D, as per NEHRP (National Earthquake HazardResearch Programme) and IBC (InternationalBuilding Code) recommendation, the ground motionat surface level for each site class is obtained basedon nonlinear site amplification technique proposedby Raghu Kanth and Iyengar (2007) for PeninsularIndia. Spatial variation of PGA values at ground levelfor site classes A to D is presented. Response spectraat rock level and at ground level for important cities

like Gulbarga, Belgaum, Hubli, Bellary, Bangalore,Mangalore, Mysore and nuclear site at Kaiga inKarnataka were evaluated and the results arepresented in this paper.

S9_C1

Seismic hazard deaggregation in terms ofmagnitude, distance and azimuth at main citiesof northern Algeria.

M. Hamdache1(E-mail: [email protected]),J.A. Peláez2(E-mail : [email protected]),A. Talbi1, M. Mobarki1 and C. LópezCasado3(E-mail : [email protected] )(1Departement Études et Surveillance Sismique,CRAAG, Algiers, Algeria., 2Department ofPhysics, University of Jaén,Spain, 3Department ofTheoretical Physics, Univ. of Granada, Granada,Spain,

The recent seismic activity in northern Algeria,especially in the last 50 years, is characterized bythe occurrence of several damaging earthquakes.The El Asnam region suffered the most destructiveand damaging earthquakes recorded in northernAlgeria, namely those of September 9, 1954 (MS6.8) and October 10, 1980 (Mw 7.3). The mostsignificant and recent event is the May 21, 2003(Mw 6.9) Zemmouri earthquake, located at around50 km northeast of Algiers. In this context, theinterest of the scientific community regardingseismology and seismotectonics has greatlyincreased in Algeria, especially in the fields relatedto the seismic risk assessment of urban seismic areasand its possible reduction. We focus on theprobabilistic seismic hazard in terms of PGA with10% probability of exceedance in 50 years, whichgenerally forms the basis for the seismic designprovision of National Building Code. In this study,we disaggregate the probabilistic seismic hazardresults in terms of magnitude, distance and azimuth,at several cities in Northern Algeria, to helpunderstand the relative contributions of the differentseismic focuses. These results are used to derive ateach studied site a probabilistic seismic hazard curveby combining the contribution of the different seismicsources or scenarios. Also, based on these results,

6922 - 24 January, 2011


we compute the so-called control earthquake, thatis, the most contributing earthquake to seismic hazardin a certain location from a probabilistic point of view.The calculation is performed for all main cities innorthern Algeria, corresponding to the so-called 2Dhazard disaggregation technique, which allows us toderive the mean and modal scenario at each site.Afterward, the mean and modal scenarios are usedto simulate design accelerograms at each place forrock soil type.

Keywords: Probabilistic seismic hazard,deaggregation, scenarios, control earthquake,stochastic simulation of accelograms, Algeria.

2C_9S

Determination Site Effect of Zarqa City-JordanBased on Microtremors Field Measurements:A microzonation Study By

Waleed Eid Olimat (Natural Resources Authority(NRA), Jordan Seismological Observatory (JSO)11118, P.O.Box # 7, Amman – Jordan, E-mail:[email protected])

Zarqa governorate is one of the importantgovernorates in Jordan. It is the second populatedafter the capital Amman, the location of Zarqa givesthe city a great importance because it lies on themain high ways leading to Syria, Iraq and SaudiArabia, most of Jordan’s industries, power plants andstrategic projects are located in Zarqa, which givesthis city a special importance.

The Nakamura’s technique is applied in this studyfor both areas; Zarqa city and Hashemite UniversityCampus in order to determine the resonancefrequencies and amplification factors for each sitethen draw there maps which will be of a great use inthe field of civil and structural engineering byenriching the building codes.

The results of our study show that; values ofresonance frequency F are not affected by the timeof recording. While values of amplification factor Acan vary accordingly. Results also show that theamplification factor A varies from 0.8 to 8.55 in Zarqacity and the resonance frequency (F) also variesbetween 0.37 Hz and 2.98 Hz in Zarqa city , that

means some constructions in the study area, in caseof a major earthquake, may experience minordamages respectively.

S9_C3

Probabilistic Seismic Hazard Analysis forMitigating Societal Risk from Earthquakes

Dr. Praveen K. Malhotra (Strong Motions Inc.,Sharon, MA, USA, E-mail: Praveen. E-mail:[email protected]), P.E. (StrongMotions Inc., Sharon, MA, USA)

A new method of computing the probabilistic seismichazard analysis (PSHA) will be discussed. Thecurrent method does not capture the aggregate (orsocietal) aspect of seismic hazard; therefore it is notsuitable for assessing and mitigating the societal riskfrom earthquakes.

Earthquakes affect many people at the same time.They pose risk to individuals as well as to the society.The design ground motions in the current loadingstandards (such as IS 1893-2002 and ASCE 7-2010)are based on site-specific probabilistic seismic hazardanalysis (SS-PSHA). The site-specific hazard isdefined by the probabilities of exceeding differentlevels of ground shaking at specific locations. Thesite-specific hazard does not say how many otherlocations will also experience the same or higherlevels of ground shaking during the same earthquake.This is a significant shortcoming of the SS-PSHA,because the exceedance of design ground motionfor 10,000 buildings has a very different effect onthe society than the exceedance of design groundmotion for a single building. A new definition ofprobabilistic hazard was proposed to capture theaggregate (societal) aspect of earthquakes(Malhotra 2007, 2009). The aggregate seismichazard is defined by the probabilities of exceedingdifferent levels of ground shaking simultaneously(during the same earthquake) at many locationsoccupied by more than a certain number of people.For example, what is the annual probability ofexceeding 0.1 g acceleration at a location along withmany other locations occupied by > 1 million people?

The importance of aggregate probabilistic seismichazard analysis (A-PSHA) will be highlighted by


70 22 - 24 January, 2011

identifying the limitations of SS-PSHA. Somepreliminary results of aggregate hazard will bepresented. Finally, a new method of establishingdesign ground motions for mitigating both individualand societal risks from earthquakes will be presented.

S9_C4

Influence of Source and Epicentral Distance onLocal Seismic Response in Kolkata city, India.

William K. Mohanty1

(E-mail: [email protected]),Akhilesh K. Verma1, Franco Vaccari2, 3,Giuliano F. Panza2, 3 ( 1Department of Geologyand Geophysics, Indian Institute of Technology,Kharagpur–721 302, India.,2Department ofGeosciences, University of Trieste, Italy., 3TheAbdus Salam International Centre for TheoreticalPhysics, Earth System Physics Section/SandGroup, Trieste, Italy.)

Kolkata, the capital of West Bengal state is one ofthe oldest industrial cities in India. It is situated overthe thick alluvium of the Bengal Basin, where it liesat the boundary of the zone III and zone IV of theseismic zonation map of India. The rapid increase inpopulation density and industrial developments acrossthe city has increased the seismic risk and thereforeit is important to access the seismic hazard of thecity for civil engineers and city planner for any futurecivil constructions. The influence of source andepicentral distance on the local seismic response inthe Kolkata city is investigated computing the seismicground motion along 2-D geological cross-sectionsin the Kolkata city for the earthquake occurred on12th June, 1897, (Mw = 8.1; focal mechanism: dip =57°, strike = 110° and rake = 76°; focal depth = 9km) in Shillong plateau. To estimate ground motionparameters, the hybrid technique is used, which isthe combination of modal summation and finitedifference method and it allows the estimation ofsite specific ground motion for various events locatedat different distances from Kolkata city taking intoaccount simultaneously the position and geometryof the seismic source, the mechanical properties ofthe propagation medium and the geotechnicalproperties of the site. The epicenter of the Shillongearthquake is about 470 km away from Kolkata. The

estimated peak ground acceleration (PGA) variesin the range of 0.11–0.18 g and this rangecorresponds to the intensity of IX to X on Mercalli-Cancani-Sieberg (MCS) scale and VIII on ModifiedMercalli (MM) scale. The maximum amplificationin terms of RSR varies from 10 to 12 in the frequencyrange 1.0–1.5 Hz. These amplifications occur incorrespondence of low velocity, shallow lose soildeposit. The comparison of these results with earlierones obtained considering the Calcutta earthquakeoccurred on 15th April, 1964 (Mw = 6.5; focalmechanism: dip =32°, strike = 232° and rake = 56°;focal depth = 36 km) show that the sourceparameters (magnitude and focal mechanism) andepicentral distance play an important role on siteresponse. The obtained results match with observedreported intensities in Kolkata region.

Keywords: Kolkata city, Eocene Hinge Zone(EHZ), AMAX, response spectral ratio (RSR), peakground acceleration (PGA), seismic sources, siteresponse, hybrid technique.

S9_C5

Neo-Deterministic and Probabilistic SeismicHazard Assessments: a Comparison over theItalian Territory

E. Zuccolo1, F. Vaccari2,3, A. Peresan2,

3(E-mail: [email protected]) and G. F. Panza2,3

(1EUCENTRE - European Centre for Trainingand Research in Earthquake Engineering, ViaFerrata, 1 - 27100 Pavia – Italy.,2 Department ofEarth Sciences, University of Trieste, via E. Weiss1, 34127 Trieste, Italy., 3 The Abdus SalamInternational Centre for Theoretical Physics,ICTP, 34100 Trieste, Miramare, Italy.

Recent strong earthquakes that have occurred inareas where neo-deterministic (NDSHA) mapswere available, successfully confirmed the neo-deterministically predicted ground shaking (e.g., theBoumerdes and Gujarat events), while theprobabilistic estimates turned out to be severelyunderestimated. Estimates of seismic hazard obtainedusing NDSHA and the probabilistic approach(PSHA) are compared for the Italian territory. Thiscomparison is, in fact, possible only in Italy thanks to

7122 - 24 January, 2011


the unique length of its earthquake catalogue. TheNDSHA provides values larger than those given bythe PSHA in areas where large earthquakes areobserved and in areas identified as prone to largeearthquakes, but lower values in low-seismicityareas. These differences suggest the adoption of theflexible, robust and physically sound NDSHAapproach to overcome the proven shortcomings ofPSHA, thus allowing for a reliable seismic hazardestimation, especially for those areas characterizedby a prolonged quiescence, i.e. in tectonically activesites where events of only moderate size haveoccurred in historical times.

S9_C6

Evaluation of site classification for soils inLucknow urban centre And Correlationbetween SPT-N value and Vs

Abhishek Kumar, P. Anbazhagan (E-mail:[email protected]), Sitharam T G(Department of Civil Engineering, Indian Instituteof Science, Bangalore, Karnataka 560012, India)

Evidences from past earthquakes clearly shows thatthe damages due to an earthquake and its severityare controlled mainly by three important factors i.e.,earthquake source and path characteristics, localgeological and geotechnical characteristics, structuraldesign and construction features of structures.Generally, the soil layers over the firm bedrock mayattenuate or amplify the bed rock earthquake motiondepending upon geotechnical characteristics, theirdepth and arrangement of soil layers. Usually theyounger softer soils amplify ground motion relativeto older, more competent soils or bedrock. Localamplification of the ground is often controlled by thesoft surface layer, which leads to the trapping of theseismic energy, due to the impedance contrastbetween the soft surface soils and the underlyingbedrock. Many researchers have proved that siteconditions play an important role in damagedistribution as well as in the recorded strong motionrecords (Ishihara, 1997; Aki, 1998; Tertulliani, 2000;Hartzell et al., 2001, Ozel et al., 2002). It has beenevident from the past earthquake events all over theworld that the amplification of ground motion is highlydependent on the local geological, topography and

geotechnical conditions. The determination ofgeotechnical site conditions requires identification ofthe soil stratification and properties of soil layers basedon various in-situ tests and laboratory tests on soiland rock samples. The extent of area to beinvestigated for seismic microzonation generallyspans over several kilometers unlike routinegeotechnical site investigations and thus, geophysicaltests are more reliable tools for understandingsubsurface. They are based on the propagation ofbody waves and surface waves, which areassociated to very small strain (< 0.001%). Thegeophysical tests are more advanced now a days,and these methods can be used more efficiently withless time to explore deeper depth and also largeraerial extent, which is quite needed mainly in deeperbasins like Indo-Gangetic basin and large urbancentre.

This paper presents Multichannel analysis of SurfaceWaves (MASW) tests carried out at Lucknow urbancentre, capital city of Uttar Pradesh, which lies inIndo-Gangetic basin. 50 MASW surveys have beencarried out and in addition, 12 numbers ofconventional bore holes were drilled with SPT testsat different depth intervals. These tests were doneas part of the study of seismic microzonation ofLucknow urban centre. Additional SPT data werealso collected from couple of geotechnical firms inthe study area. Out of these data, 14 pairs of dataconsisting of MASW and SPT tests in boreholeswere close to each other. Based on Vs profiles fromMASW tests, it has been observed that Lucknowurban centre belong to site class D and C, as perNEHRP classification. Similar classification was alsoattempted from SPT data. Further, from these 14sets, about 220 pair of data of uncorrected SPT-Nvalue and Vs were compared and correlated.Through a regression analysis, an empiricalcorrelation was obtained between SPT ‘N’ valuesand Vs values for the region under study. Thesummary of correlation developed and itscomparison with similar correlation available inliterature are also presented in the paper.

Keywords: Site classification, Shear wave velocity,Multichannel analysis of Surface Waves (MASW)test, Standard Penetration Test (SPT)


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S9_C7

Site Response Studies in the Andaman andNicobar Islands

K Sushini (E- mail: [email protected]);Namita Pegu, N. Purnachandra Rao, M. Ravikumar (National Geophysical Research Institute(Council of Scientific and IndustrialResearch)Uppal Road, Hyderabad – 500007)

Site- response in the Andaman and Nicobar Islandsregion is investigated using the standard Nakamuratechnique. The predominant frequencies (f0) of theuppermost layer and the site amplification areestimated at broadband stations along the Andaman-Nicobar Islands, based on the H/V spectral ratios.The method was applied on ambient seismic noisetime-series as well as on earthquake waveform datarecorded at all seismic stations. Ground amplificationsup to 2 or 3 times are estimated predominantly in thefrequency range of 3 – 4 Hz. Also considerableamplifications are seen at 7 Hz. The obtained resultswere also correlated with the local geology, theobserved macroseismic intensities and with thetheoretical estimates of resonant frequencies .Thethickness of the soil layer (h), obtained from borelogs and the soil layer resonance frequencies (f0)determined from the H/V spectral peaks are usedto obtain a regression relation given by. This relationcan be used for estimating the depth to bedrock inthe Andaman – Nicobar Islands using microtremordata at locations where borehole data is not available.

S9_C8

Analysis of Embedded Pipeline Induced byEarthquake Excitation under Various SoilMaterial Types

Goktepe F. (E-mail: [email protected]);Kuyuk H.S. (E-mail: [email protected]);Celebi E. (E-mail: [email protected])(Department of Civil Engineering, SakaryaUniversity, Sakarya, Turkey)

Earthquakes have destructive influences onto lifelineengineering and especially leading to considerableeconomic loss to the underground structure.Underground structures are significant unit of lifelineengineering. The Southern Caucasus- EasternTurkey energy corridors are formed by several

critical pipelines carrying crude oil and natural gasfrom Azerbaijan, via Georgia, to Turkey and worldmarkets. Many project accomplished andconstruction of new corridors are still going on. Thisstudy is dealt with the modeling and assessment ofembedded pipelines under various soil material typessuch as Linear-elastic model, Mohr-Coulomb modeland Hardening soil model induced by earthquakeexcitation. Due to difficulties in setting upexperimental studies and high expenditures, discretecomputer models used for numerical simulationconsidering soil- infrastructure interaction effects viaa two dimensional (2D) finite element method in timedomain (Figure 1). Absorbent boundary that doesn’treflect seismic waves in the numeric soil-infrastructure model was used. Comprehensiveanalyses for embedded pipeline are performed andobtained results are evaluated.

Figure 1. The typical numerical model FE-mesh withpipeline

Keywords: Embedded pipeline, dynamic FEanalysis, soil-infrastructure model, soil materialtype.

S9_C9

Seismic Hazard Assessment of Gujarat

K. S. Vipin11, T. G. Sitharam2 and SreevalsaKolathayar3 (1 Post Doctoral Fellow, 2Professorand 3 Research Scholar, Department of CivilEngineering, Indian Institute of Science (IISc)Bangalore – 560012 )

The state of Gujarat falls in seismic zone V of theIndian seismic code BIS-1893(2002). Incidentally thisis the only region in the stable continental shield whichis in seismic zone V. This indicates the importanceof carrying out a seismic hazard assessment for theGujarat region. More over the Bhuj earthquake in2001 is the deadliest continental shield earthquakeever occurred. This paper tries to evaluate theseismic hazard of the state of Gujarat based onProbabilistic Seismic Hazard Analysis (PSHA)

7322 - 24 January, 2011


method. The earthquake catalogue for Gujarat willbe prepared by collecting the data from national andinternational agencies. The seismic sourceidentification - both linear and areal will be done andusing these two types of sources, the hazardassessment will be carried out. In addition ot thetwo types of sources, multiple attenuation relationswill also be used and these different models will becombined using a logic tree approach. The hazardassessment will be done with a grid size of 10 km x10km. Maps showing the spatial variation of peakhorizontal acceleration (PHA) values for differentreturn periods at bed rock level for the entire statewill be presented in the paper. The response spectrafor selected cities will also be developed.

S9_C10

Earthquake Hazard Assessment for PublicSafety

Lalliana Mualchin (E-mail: [email protected],Retired Chief Seismologist, Office of EarthquakeEngineering, California Dept. of Transportion,Sacramento, California and Seismic Consultant tothe Govt. of Mizoram, India, Disaster Mangement& Rehabilitation Dept., Govt. of Mizoram, Aizawl)

Catastrophic disasters are usually caused by largeearthquakes to the unprepared community and whosestructures are not designed and constructed towithstand the earthquake hazard load. Earthquakescience provides the framework for assessing thehazard. The use of realistic estimates of hazards frompotential large earthquakes for designing andconstructing structures is one of the keys to publicsafety.

The traditional approach of earthquake hazardestimate is straightforward, defining the largestearthquake (maximum credible earthquake, MCE)magnitude that each of the considered sources/faultsor areas can generate using (1) empiricalrelationships between magnitudes and fault lengthsor areas for various fault types, or (2) seismicity.Hazard (e.g., vibratory strong ground motions) at asite or an area is estimated by applying themagnitudes and distances to the adopted attenuationrelationships which show ground motions (e.g., peakground acceleration) as a function of distance forvarious magnitudes. The use of the largest potential

earthquake magnitude supercedes or automaticallyconsiders all the smaller events.

Another approach have been introduced mainly todefine equitable hazards from the sources and alsoto reduce uncertainties in various steps of theassessment procedure. The rarity or unlikelyoccurrence of MCE during the life of structure aswell as too high cost for using MCE have beenanother motivation for the new approach which isknown as probabilistic seismic hazard analysis(PSHA). To distinguish it from PSHA, the traditionalapproach is renamed deterministic seismic hazardanalysis (DSHA). Without debates or discussionson the merits of PSHA, it has been formalized andheavily promoted in California, including its use inthe U. S. nuclear powerplant regulations and in theGlobal Seismic Hazard Map (GSHAP) project, eventhough DSHA is favored and continously used byengineers. Features of the approaches, includingundebated rarity and cost factors, from the point ofview of a practitioner for public safety will be given.

Errors recently found in the theoretical foundationof PSHA by Jens Klugel and others; its unrealisticresults in recent critical projects and observationswill be presented. Too low hazard estimate notedfor recent damaging earthquakes, particularly in arelatively low seismic-active regions such as in thePeninsular India or for the slow slip-rate faults insouthern California, e.g., the 1992 Landers, 1994Northridge and 1999 Hector Mine earthquakes, aswell as for the Kobe 1995; Gujarat, 2001; Algeria2003; Iran 2003; China 2008; and Haiti 2010earthquakes are noteworthy. In contrast, DSHAresults continue to be considered realistic and reliablefor engineering.

Finally, problems encountered and progress in thedevelopment of a deterministic seismic hazard mapfor the state of Mizoram, within the highest seismiczone V in India, will be discussed to show the need todo earth science study and to record strong motionsin such remote and highly seismic-active regions ofthe world. Various ideas on the nature and geometryof the Indo-Myanmar subduction zone will bepresented as the dominating structure. The unrealisticGSHAP map for the region in consideration of thedominant earthquake source zone may do more harmthan good in misleading the community.


74 22 - 24 January, 2011

S9_P1

Geo-informatics based conceptualization ofEarthquake Disaster Management System

Ajeet P. Pandey (E-mail: [email protected]),R.K. Singh, A.K. Shukla (Earthquake RiskEvaluation Center, India MeteorologicalDepartment, New Delhi)

The whole world today is highly prone to disasters,risks and uncertainties than ever before. A largeproportion of humanity is constantly at risk due todeteriorating environment, climatic variability, growingpopulation and the increased frequency of suddennatural catastrophes. Recent years have witnessedalarming increasing trend in occurrence of naturaldisasters as well as their magnitudes of impact. InIndia, there had been several natural catastrophicdisasters like Cyclones, Earthquakes, Tsunami,Floods, Draught, Landslides and Forest Fire etcwhich have severely been affecting the country formany decades. Super Cyclone in Orissa, Earthquakein Kachchh Gujarat and recently occurred Tsunamiin the Indian Ocean originated due to the GreatSumatra earthquake are the most devastatingdisasters that country has witnessed in the recentpast. Study reveals that in India most disastrouscatastrophe amongst all these are Earthquakes, whichdevastate the country by killing several hundreds ofhuman lives, rendering thousands of people homelessand destroying enormous Public and NationalProperties. An efficient GIS based near real timeearthquake disaster management is indeed the needof the hour to tackle this frightening situation in thecountry.

Geo-informatics is a powerful tool that develops anduses information science infrastructure to addressthe problems of geosciences. Geo-informaticscombines geospatial analysis and modeling,development of geospatial databases, informationsystems design, human-computer interaction andboth wired and wireless networking technologies. Itprimarily includes Remote Sensing (RS), GlobalPositioning System (GPS) and GeographicalInformation System (GIS) that have become anintegrated, well developed and successful tool indisaster management. Geo-informatics, in recentyears, has been the subject of consideration with

regards to disaster management programsworldwide.

In this paper, role of geoinformatics as a powerfultool for collecting, storing, retrieving, transforming,displaying and disseminating spatial data from a realworld is discussed in context to earthquake disastermanagement. It emphasizes on the application ofRemote Sensing and GIS for the preparation of multi-thematic maps using various spatial, non-spatial andattributes data with regards to preparedness,prevention, planning/mitigation, rescue and reliefagainst the disaster. Digital image processing on onehand facilitates to analyze and capture the spacedata for geology, geomorphology, land use/land cover,drainage pattern, slope & aspect, palaeochannelmapping, seismotectonics and image classificationof the study area. At the same time GIS provides apowerful platform to utilize and handle efficientlythose data for spatial analysis and integrating themto prepare digital thematic maps with high precisionthat finally strengthens the decision supportmechanism. This paper conceptualizes the near realtime earthquake disaster management system inperspective of geo-informatics that would helpminimizing the effects of earthquakes significantly.

Key words: Geo-informatics, Remote sensing,Digital image processing, GIS, Earthquake, Thematicmaps, Disaster management.

S9_P2

Probability of Occurrence of Largest Earth-quakes in Jharkhand and nearby Region inDifferent Periods Based on Gumbel’s Theory

Akash Adwani, Deepanshu Melana, YogeshArora (E-mail: [email protected]), andVK Srivastava (Dept. of Applied Geophysics,Indian School of Mines, Dhanbad (India)

The state of Jharkhand plays an important role inthe progress of India as it is rich in coal and othermineral resources and many important industrieshave come up which are growing at a faster ratethan expected. Therefore though the seismic risk inthe region is apparently low but never the less itcannot be ignored and needs to be studied for thesafety of the properties and life from any sucheventuality. So in order to ensure the safety it isnecessary to study the pattern of occurrence of

7522 - 24 January, 2011


earthquake and associated risk using the appropriatestatistical tools.

In general the seismicity characteristics of theJharkhand resemble those of Stable Continentalregion (SCR) as is observed for southern peninsularregion of the Indian sub continent. The state hasexperienced nearly 30 earthquakes in the past andhaving magnitude ranging from 3 to 6 during last147 years. These earthquakes are of shallow/crustalin nature and is scattered all over the area. It can beseen from the seismicity map that the frequency ofthe earthquakes has been increasing since the year2000 and hence this requires quantitative analysis ofpattern of occurrence as well calculation ofassociated seismic risk in the region.

In present paper statistical approach of ExtremeValue method as described by Gumbel (1958) hasbeen applied by taking data set of data of the year1862 to 2009.As it appears that the data set may notbe complete we choose this method utilizing thelargest observed earthquake in a time span. Thismethod has been applied for various other regionsof world by various workers viz.; Karnik andSchenkova, 1974; Tezcan, 1996; Ozmen, et al, 1999;

From the present study it has been concluded thatthe seismic risk in the region has increased and sincethen there is high probability of occurrence of seismicevents of magnitude in a range of 4 to 5 in a periodof 50 years which decreases as we go for highermagnitudes. Also the return period is quite high aswe move on to greater magnitudes like 6 to 7 (70 to230 years) but for lower magnitudes it is still a matterof concern (7 to 22 years). However as our periodof the data taken is small considering tectonic historyof the region one has to consider applying techniqueof paleoseismic study in order to delineate activeseismotectonics in the geological past and thusunderstanding the seismicity pattern and associatedrisk in the region.

S9_P3

Preliminary Site Characterization throughIntegration of Geophysical and GeotechnicalData at Gujarat International Finance TechCity, Gandhinagar in Gujarat, India

B.K. Rastogi, A.P. Singh, Sandeep Agrawal,Sumer Chopra, B. Sairam, Kapil Mohan,

Janki Desai, Luangmei Limpou, MaibamSarda, Ranjana Noarem, Jaina Patel, PoojaRamanuj, Ashish Bhandari and Surya Prakash(Institute of Seismological Research, Raisan,Gandhinagar-382009, Gujarat, India.)

Geophysical and Geotechnical investigations are usedfor site characterization studies at GujaratInternational Finance Tech (GIFT) City, Gandhinagarin the Gujarat state. The investigations have beencarried out at around 506 acre of land at Gandhinagar.The proposed Buildings for construction aremultistoried township and corporate offices. Theground and height of building will exceed 80 stories(100m and above). Here geophysical investigationslike Microtremor array survey, Multichannel analysisof surface wave (MASW), PS-logging andEarthquake observations have been carried out atwell distributed site to determine the site amplificationcorresponding to the amplified frequencies and therelevant shear wave velocity profile of the deepsedimentary basin. Furthermore, geotechnicalinvestigations as SPT N-values, grain size analysis,litholog analysis are done at locations of geophysicalobservations. From these combined studies, we haveobserved various geological boundaries with depthlike Holocene1-Holcence-II, Holocene-Pleistocene,Quaternary-Tertiary and Tertiary-Deccan trap. Wehave also estimated the Engineering Bed Rock(EBR) according to soil type and shear wave velocitystructure.

At GIFT City (Gandhinagar), an impedance contrastis observed at 400 m depth for frequency of 0.65-0.7Hz with 3 times amplification, which may be dueto Quaternary-Tertiary boundary. Another peak isobserved at the frequency of 4Hz with 2-3 timesamplification due to Holocene I – Holocene IIboundary at 40 m depth. Resonance frequency of1.5Hz corresponds to Holocene-Pleistoceneboundary at 150m depth, which is taken as EBRbeing omnipresent. In addition, the earthquakerecords show a peak at around 0.1Hz; this could bedue to Tertiary- Deccan trap boundary at 4000 mdepth.

Integrated geophysical and geotechnical resultsshow that the upper most layer up to 0-40 metershas the low shear velocity between 175-500 m/s.The second layer is to the depth of 45-60 meters


76 22 - 24 January, 2011

with shear velocity 700-900 m/s and the third layeris to depth of 100-250 m with shear velocity 1000-1800 m/s. These layers may be suggested to beQuaternary deposits of Holocene I, Holocene II andPleistocene. By definition the EBR should beuniformly distributed and beneath EBR there is lessvariation of structure and properties. From theseconsiderations, the boundary of Holocene-Pleistocene at around 150 m is considered to beEBR.

S9_P4

Preliminary Site Characterization throughIntegration of Geophysical and GeotechnicalData at Dholera Special Investment Region inGujarat, India

B.K. Rastogi, A.P. Singh, Sandeep Agrawal,Sumer Chopra, B. Sairam, Kapil Mohan,Janki Desai, Luangmei Limpou, MaibamSarda, Ranjana Noarem, Jaina Patel, PoojaRamanuj, Ashish Bhandari and SuryaPrakash(Institute of Seismological Research(ISR), Raisan, Gandhinagar-382009, Gujarat,India.)

Geophysical and Geotechnical investigations are usedfor site characterization studies at Dholera SpecialInvestment Region (DSIR) between Ahmedabadand Bhavnagar in the Gujarat state. Here geophysicalinvestigations like Microtremor array survey,Multichannel analysis of surface wave (MASW),PS-logging and Earthquake observations have beencarried out at well distributed sites to determine thesite amplification corresponding to the amplifiedfrequencies and the relevant shear wave velocityprofile of the deep sedimentary basin. Furthermore,geotechnical investigations as SPT N-values, grainsize analysis, litholog analysis are done at locationsof geophysical observations. From these combinedstudies, we have observed various geologicalboundaries with depth like Holocene1-Holcence-II,Holocene-Pleistocene, Quaternary-Tertiary andTertiary-Deccan trap. We have also estimated theEngineering Bed Rock (EBR) according to soil typeand shear wave velocity structure.

At DSIR, H/V spectral ratios using ambientvibrations and earthquake records indicate dominantfrequency range 0.29-0.50Hz, corresponds 4-6 times

amplification. If the thumb rule apply f=Vs/4H forthe thickness of the layer is applied for the Vs profileat the sites, the depth corresponding to suchfrequency is around 350m depths of Deccan Trap,when average shear wave velocity for Tertiary isset to be 700m/s. This is justified by depth of 354 mat which Deccan Trap is encountered by ONGC.Other peaks present are at frequency range 1-2 Hzand 4-6 Hz with around 2 to 3 times amplification.These dominant frequencies can be interpreted asshallower layer of impedance contrast at boundariesof Pleistocene-Holocene and Holocene I-HoloceneII layers.

Integrated geophysical and geotechnical results atDSIR show that the upper most layer up to 0-30meters has the low shear velocity between 170-350m/s. The second layer is to the depth of 45-60 meterswith shear velocity 400-700 m/s and the third layeris to depth of 80-100m with shear velocity 750-1500m/s. These layers may be suggested to beQuaternary deposits of Holocene, Pleistocene andTertiary. The shear wave velocity of the last layer is2000-2700 m/s corresponding to Deccan Trap. Theboundary of Pleistocene-Tertiary at around 80 m isconsidered as EBR at DSIR as it is uniformlydistributed in the area and under it there is lessvariation of structure and properties. The Secondlayer is soft soil while the third is soft rock.

S9_P5

Estimation of Liquefaction Potential of DholeraRegion Based on SPT N-values

Sarda Maibam (E-mail: [email protected]),Ranjana Naorem, Pooja Ramanuj, Jaina Patel(JRFs) (Institute of Seismological Research,Raisan Village, Gandhinagar- 382009.)

Liquefaction is known as one of the most destructivephenomena caused by earthquakes and has beenwidely seen in saturated soil deposits (Niigata, 1964;Alaska, 1964; Tangshan, 1979; Loma Prieta, 1989;Kobe, 1995, Turkey, 1998; Chi-Chi, Taiwan, 1999).Liquefaction may be defined as the transformationof a granular material from solid state to liquid statedue to increase in pore pressure and reducedeffective shear strength and will behave more like afluid (Marcuson 1978).The purpose of this study isto determine Liquefaction Potential of Dholera SIR.The required parameters for estimating liquefaction

7722 - 24 January, 2011


potential are lithology of the area, geotechnical soilproperties (fine content, plasticity index, D10 andDavg), converted Standard penetration resistancevalue (N1)60, ground water level, Horizontal SeismicCoefficient (kh). In the study area, 87 boreholes weredrilled, out of which 80 boreholes were taken intoconsideration for estimating liquefaction potential.Penetration corrections were carried out for the SPTN-values greater than 100 in order to get the absoluteN value (Nc) and for normalization of overburdenstress to achieved standardized value of (N1)60(Robertson & Fear, 1996).

Considering our available geotechnical data, theJapanese Road Association Methodology was usedfor the estimation of the liquefaction potential. Themethodology comprised of two steps namely FL andPL estimation. In this study, the earthquake type wasdecided based on the parameter Cw (Correlationcoefficient for earthquake), adopted as “Type 2”(Type-1=Inter-plate; type-2=Intra-plate earthquaketype) as according to the seismotectonic context ofthe scenario earthquakes in India. FL estimationcalculates a safety factor for each borehole downto depth of 20 m, which is the most susceptible zonefor liquefaction. Liquefaction potential for each gridis evaluated by the PL estimation, for pre & postmonsoon period.

According to Iwasaki et al. (1982), sites with PLvalues e” 15 suffer severe liquefaction effects andwith PL < 5, least liquefaction. The liquefactionpotential of Dholera SIR is very low i.e 0d”PLd”3,except only at one site which shows very highpotential i.e PL=32.7(on east-central part, which isin vicinity of the Gulf of Cambay). A total of 20borehole sites are non-liquefiable. Among the 60liquefiable boreholes, 54 have very low (PL=0), 5have relatively low (0 < PL <= 5) and one is relativelyhigh (PL>15) for the Dholera SIR.

S9_P6

Vs30 and Site Amplification studies in DholeraSIR Region, Gujarat, India

B. Sairam(E-mail: [email protected]),B. K. Rastogi, Sandeep Aggarwal, K. S. Roy,Kishansinh Zala, Mehul Jagad and VandanaPatel (Institute of Seismological Research,Raisan-382009 Gandhinagar)

In order to clarify the dynamic soil property ofDholera region, Shear-wave velocities (Vs) weremeasured by Multichannel Analysis Surface Wave(MASW) (41 sites) and Suspension PS-logging (16sites) in Dholera SIR. These sites are well distributedin the area and covered three geomorphological unitsviz New-Mud Flat (NMF), Salt-Flat (SF) and Old-Mud Flat (OMF) of the study region. StandardPenetration Test (SPT) was also carried out at eachPS-logging site. The PS-Logging results show goodcorrelation with SPT N-values. Most of the 1-D Vsprofiles by MASW and PS-logging show that Vsincreases steadily from nearly 200m/s at near surfaceto 400m/s at 30m depth. Average of Vs within 30 mdepth (Vs30) of all sites of study area is in the rangeof 190 to 340 m/s. In view of this, the study regioncan be classified as D-class according to the NEHRPclassification. Maximum depth up to which Vs ismeasured by the PS-logging is 84 m and by theMASW is 69 m. Contours of the Vs30 are showinggood correlation with all three geomorphological unitsof the region. The NMF has lowest Vs30 (Vs30 ~200 10 m/s) while the OMF has highest Vs30 (235- 340 m/s) among all the geomorphological units inthe study region. The Vs30 of the SF is 22010 m/sand is higher than those at the NMF. Further, SiteAmplification (SA) has been estimated usingearthquake records at 11 sites. The sites of SA werewell distributed and covered all threegeomorphological units of the study region. SA upto 6.7 is observed in frequency range of 1.2 -4.6 Hz.SA of the NMF, the SF and the OMF are in therange of 6- 6.7, 4.3 - 6 and 3.7 - 4.7 respectively. Aplot of Vs30 versus SA is showing that amplificationincreasing with decreasing Vs30. Thegeomorphological units which have low Vs30 areshowing higher SA while those units which havehigher Vs30 are showing low SA. From aboveobservations it is inferred that Vs30 is good proxyfor site amplification.


78 22 - 24 January, 2011

S10_I1

Seismotectonics and velocity structure of theKumaon - Garhwal Himalaya

P. Mahesh1 (Email: [email protected]),S.S. Rai1, Sandeep Gupta1, Rajgopal Sarma1,Ajay Paul2, K.S. Prakasam1 (1 NationalGeophysical Research Institute (CSIR),Hyderabad, India, 2 Wadia Institute ofHimalayan Geology, Dehradun, India)

We present the detailed seismicity pattern,earthquake mechanics and velocity image of theKumaon-Garhwal Himalaya. We use localearthquakes recorded during April 2005 to June 2008by a temporary network of 51 broadband seismicstations operated by the National GeophysicalResearch Institute (NGRI, 40 stations) and WadiaInstitute of Himalayan Geology (WIHG, 11 stations).1-D velocity model for the region is generated usingVELEST with 385 local earthquakes each with atleast 8P and 5S phase readings and azimuthal gap<180°. This 1-D velocity model is used to relocateall the recorded 1250 earthquakes. The majority ofearthquakes follow the trend of the MCT zone,however, we also observe earthquakes beneath theGanga basin, lesser Himalaya, higher Himalaya andfurther north of the STD. Further refinement of thehypocentral parameters using HypoDD relocationprogram results well constrained locations. Though

the majority of earthquakes have their genesis in theupper crust (up to 20 km), significant number ofearthquakes are located in the mid-lower crust, aswell. Unlike the Nepal Himalaya, we have no reliableearthquake in the shallower mantle suggesting alateral diversity in the rheological property of theIndian lithosphere under-thrusting the Himalaya. Thefocal mechanisms are predominantly of thrustmechanism. The P-axis directions of earthquakefocal mechanisms are clearly oriented along thenorth-northeast trending direction of Indian platemotion with respect to Eurasian plate. The maximumcompressive stress direction is NE-SW oriented,consistent with the relative plate motion of the Indianplate. We also determine 3-D seismic velocity andPoisson’s ratio variations using local earthquaketomography. We observe 6-7 km thick zone of low-Vp, low-Vs and high Vp/Vs in the upper crustbeneath HFT, and attribute it to sediments in theregion. This low-Vp zone smoothly dips in the northand suddenly dips significantly beneath MCT. Thedipping of this low-Vp can be the expression of upperpart of the down going Indian crust. Vp in mid crustis generally low, while the Vs is high. It appears thatthe cause of much of this complexity may be due tothe change in velocity distribution in the upper 6 kmto below 20 km depth. Therefore, 6 - 20 km depthzone may be viewed as a transitional layer containingcontributions from structure above and below it.

S10: Tectonics and Crustal MovementsConvener : B.K. Rastogi

THEMEThe knowledge about the tectonics and crustal movements is essential for medium andlong-term assessment of seismic hazard. Various geophysical surveys determine crustaland upper mantle structure including sedimentary thickness, faults orientation, basementblock structure, Moho depth. Passive methods like seismic tomography receiver transferfunctions, shear wave splitting provide some more details like discontinuities in the uppermantle which provide clues for deeper earth processes like hot spots and disposition ofplutonic bodies which act as stress concentrator or poisson’s ratio to detect fluid fieldzones which act as asperities or lithosphere-asthenosphere boundary which providesclues for rifting episodes. The results of VLBI, GPS and InSAR measurements are inferredin term of current crustal movements and after a major earthquake pattern of deformationin respect of shear deformation or visco-elastic process/ rheology change. The sessionincludes papers on such aspects.

7922 - 24 January, 2011


S10_I2

New Evidence of the Involvement of the LowDensity Fluid Phase in the Deep Crust Seis-micity

M.V. Rodkin (International Institute ofEarthquake Prediction Theory and MathematicalGeophysics, Russian Academy of Science,Profsoyznaya Str. 84/32, 117997, Moscow, Russia,E-mail: [email protected])

The deep fluid is suggested to have important role inthe deep crust and upper mantle seismicity. Howeverfew direct evidences of the fluid involvement in thedeep crust and upper mantle seismicity are known.The differences in the earthquake depth and origintime values obtained in the examination of firstarrivals and in result of seismic moment calculationwere examined. For the case of moderate size andstrong earthquakes these differences becomes to becomparable with the measurement errors and theirstatistical examination is available. The differencein the origin time values obtained from the first arrivalsexamination and from the seismic moment solutionwas treated as an estimate of semi-duration of thefailure process in the given earthquake. Thedifference in the depth of the earthquakes obtainedfrom the first arrivals examination and from theseismic moment solution was treated as an estimateof half-size of the failure zone in depth. Theearthquakes were subdivided into two groups withthe seismic moment depth values exceeding and beingless than the depth values obtained from examinationof the first arrivals data. These groups of earthquakesare treated as earthquakes with process of failuredevelopment to the Earth’s surface and to the depth.It was found that these two groups of earthquakeshave different statistical characteristics. Theearthquakes which develop to the Earth’s surfacehave in the average lower apparent stress values,lower duration time, and greater extension on depth.These earthquakes essentially predominate in thedepth interval from 10 to 25 km depth. The revealedfeatures of such earthquakes can be caused by thedeep fluid of low density existing in the earthquakerupture zone. This fluid will have a strong tendencyof uprising to the Earth’s surface and will promotethe failure process in this direction. Thepredominance of such earthquake in the mentioned

depth interval can be connected with the developmentof different dehydration reactions expected to occurin this depth interval. The other display of the sameeffect could be the known feature of concentrationof earthquake hypocenters in the narrow sub verticalnail-like structures revealed earlier in the seismicityof the Japan Islands and in other regions.

S10_I3_

Crustal configuration and seismo-tectonics ofthe Kutch Rift Basin from analysis ofaeromagnetic Data

Mita Rajaram(Email: [email protected]), andS.P.Anand(Indian Institute of Geomagnetism,NewPanvel(W), Navi Mumbai.)

The Kutch rift basin of Gujrat (Zone V) has witnessedoccurrence of high intensity earthquakes; thecatastrophic Bhuj earthquake of 26

th Januray 2001

with magnitude Mw 7.7 (Ms8) being the mostdamaging in the last 50 years. Recently, highresolution aeromagnetic (HRAM) total magnetic fielddata were collected by Directorate General ofHydrocarbons over the Kutch Rift Basin. Theobjective of the survey was to acquire high resolutionmagnetic data to map the anomalous magnetic fielddistribution pattern in order to understand the lithologyand sub surface structural settings in aid of geologicalinterpretation. The aeromagnetic anomaly mapdepicted signatures of several major geologic andtectonic units including the trap flows, the Kutch Mainland Fault, the volcanic islands etc. From this analysiswe were able to bring out signatures of severalhitherto unknown faults and intrusives. Analysis ofthe data suggests that the shallow level magneticsources are related to trap flows and volcanic plugs.For the first time we were able to isolate the trapflows to the northwest of Kutch Mainland fault. Wefind that the epicenter of the main shock of Bhujearthquake lies on the intersection point of threeidentified faults; the epicenters of aftershocks fallon the NW-SE and NE-SW faults emanating fromthe main epicenter and these are constrained to liewithin an area defined by the faults identified fromthe aeromagnetic data. Further, these faults arerelated to the directional change of the compressionalforces on either side of the Bhuj epicenter, as


80 22 - 24 January, 2011

evidenced in the GPS data.. A magnetic sourcedistribution map along with the depth to the varioustectonic units has been generated. Results of analysesand modeling of the aeromagnetic data will bepresented.

S10_C1

Seismotectonic Studies of Kachchh Basin usingGravity surveys after 2001 Bhuj Earthquake

Rashmi Pradhan, R.K. Singh, Siddhart Dimriand Mehul Jagad (Institute of SeismologicalResearch, Gandhinagar.)

The structural configuration of Kachchh basin ischaracterized by highlands and plains, whichrepresent area of uplifts and half-graben,respectively. The uplifted blocks are bounded by E-W trending major faults, prominent among them beingKathiawar, KMF and Island Belt fault. The Bougueranomaly of Kachchh shows several gravity highsand lows, primarily attributed to fault controlledbasement uplifts and depression. It is also suggestedby gravity surveys that there is larger thickness ofsediments towards south and a general uplift ofbasement towards north, descending stepwisetowards the south, indicating post rift verticaltectonics. The Bhuj earthquakes of 26th January 2001and its aftershocks and migrated earthquakes areconcentrated in the zone of thrust faults KMF, Southand North Wagad faults and NW-SE and NE-SWstructural trends.

The Bouguer gravity map of Kachchh representsthe following features:

Zero contour between gravity high and low, isrunning almost W-E direction up to Bhachau,representing KMF.The Zero contour of gravity taking almost S-Nturn after Bhachau suggesting NW-SEboundary of an uplifted block near Manfara(South Wagad Fault) and NE-SW turn nearChobari (North Wagad Fault).The zero contour of Bouguer map near Desalparmay be representative of Gedi Fault and positivegravity region close to Desalpar may be due topresence of mafic/ultramafic bodies which needsto be verified by magnetic survey.

The N-S orientation of zero contour adjacent toUmrapar may be representative of Basementfault which separates the Khadir and Bela islands.Basement upliftment (crustal deformation) iswell reflected in the form of gravity high withingravity high zone in and around DholaviraThe trend of regional gravity anomaly showsthat the Kachchh basement is dipping towardsSE.

S10_C2

About the Geophysical studies are beingcarryout by WIHG in the NW Himalaya and theobtained preliminary results.

Sushil Kumar1 (E-mail: [email protected]),Rama Sushil2 and Ajay Paul1 ( 1Wadia Instituteof Himalaya Geology, 33 GMS Road, P.B.No.74,Dehra Dun –248 001(UA), India. 2SGRRITS, Dehra Dun –248 001(UA), India.)

The Himalaya originated as a result of continent–continent collision between India and Asia. Thenorthward convergence of India resulted in crustalshortening of the northern margin of the Indiancontinent, accommodated by south-verging thrusts.The principal thrusts, namely the Main Central Thrust(MCT), the Main Boundary Thrust (MBT) and theHimalayan Frontal Thrust (HFT) show younging ageand shallowing depth, suggesting southwardmigration of the main deformation front. Neotectonicactivity and active faulting related to the thrusts areobserved on the surface in some restricted segments.The MCT remains largely inactive, except somereactivated segments showing lateral strike-slipmovement as in Central part. The MBT in certainlocalized areas exhibits neotectonic activity. TheHimalayan Frontal Thrust (HFT) shows activefaulting and associated uplift. The HFT representsa zone of active deformation between the Sub-Himalaya and the Indian plain. It is well known thatthe frontal Himalaya has been the site of severaldevastating earthquakes. Considering that in caseof preparation period for a future large earthquake,certain precursory activities can be expected. Theunderstanding of earthquake source processes andthe medium characterization are the tools for theassessment, mitigation and reduction of seismichazard. To achieve these objectives the Geophysics

8122 - 24 January, 2011


Group of Wadia institute of Himalayan Geology(WIHG) has been operating a regional seismicnetwork in NW Himalaya since 1985. Presently, thisseismic network has 38 broadband (BBS) and 7short period seismic stations. 12 BBS stations of thisnetwork are connected through VSAT to monitorregional seismicity in real time mode at central stationDehradun. The Geophysics Group has carried outfirst ever passive seismological experiment aroundthe Eastern Himalayan Syntaxis. A linear profile of12 broadband seismic stations has been installed inLohit Valley, Eastern Hiamalayan Syntaxis forstudying the lithospheric structure and dynamics ofthe syntaxis. Investigation of geodynamicaldeformation and Crustal/Lithospheric structures ofthe Himalaya and surrounding regions is being carriedout by quantitative physical methods viz Seismologicalstudies, Global Positioning System (GPS) andelectromagnetic methods. Besides these,Multichannel Analysis of Surface Waves (MASW)and site response studies in major populated centers/cities of northern India have been carried out whichare prime input to the microzonation studies. In thispaper all the experiments and their preliminary resultswill be discussed.

S10_C3

Fractal Dimension and b-Value Mapping in NWHimalaya and adjoining regions.

Sushil Kumar1 (E-mail: [email protected]),Rama Sushil2 and Ajay Paul1 ( 1Wadia Instituteof Himalaya Geology, 33 GMS Road, P.B.No.74,Dehra Dun –248 001(UA), India.2SGRRITS, Dehra Dun –248 001(UA), India.)

The northwest Himalayan region and the adjoiningregions fall in the most intense seismic zone.Earthquakes of varying intensities have hit the regionin the past and similar threats remain imminent. Inthe last 105 years, the main earthquakes occurredare the Kangra earthquake of 1905 (Ms=8.0), theKinnaur earthquake of 1975 (M=6.8), Dharchulaearthquake of 1980 (Mw=6.5), Uttarkashi earthquakeof 1991 (Mb=6.6), Chamoli earthquake of 1999(Mb=6.8) and the Kashmir earthquake of 2005(Mw=7.6), which resulted in tremendous loss of lifeand property. The earthquakes occurrence possessesnon-linear relation with respect to space and size.Fractal dimension and b-value are determined from

2100 well-located earthquakes, recorded at 9-19seismic stations in Northwest Himalaya during 2004-2010. A detailed study of the frequency–magnitudedistribution and fractal dimension as a function ofdepth has carried out. In this paper, the resultsobtained have discussed.

S10_C4

Stress Pulse Migration by Viscoelastic Processfor Long - distance Delayed Triggering ofshocks in Gujarat after the 2001 Mw 7.7 Bhujearthquake

B.K. Rastogi (Institute of SeismologicalResearch, Gandhinagar- 382 009, India, E-mail:[email protected])

The Gujarat region in western India is seismicallyone of the most active intraplate regions. It wasknown to have low seismicity but high hazard in viewof the occurrence of several large earthquakes butfewer moderate or smaller shocks. The scenariochanged during the first decade of the 21st Centurywhen a damaging earthquake of M~5 with a longsequence of shocks occurred in Bhavnagar in theyear 2000 and M7.7 great earthquake accompaniedby 10,000 located aftershocks of Me”1. Additionally,30 felt mainshocks (of M4 or so) occurred at 20different locations in Kachchh and Saurashtra. Incontrast the earlier twenty decades experiencedhardly one or two felt shocks (barring the year 1938when 5 earthquakes of M4-5 were felt at Paliyad inSaurashtra). The Gujarat region has E-W trendingmajor faults of the failed Mesozoic rifts of Kachchhand Narmada which are getting reactivated bythrusting. There are some smaller transverse strike-slip faults. South of Kachchh, in the DeccanVolcanics of Saurshtra, the NW and NE trendingsmaller strike-slip faults are also activated in the formof moderate earthquakes in response to the plate-tectonics stress.

Aftershocks in the 2001 Mw 7.7 rupture zone inKachchh continued up to M5.7 level until 2006 andMd”5 level subsequently with earthquakes of M>4once every two months and five or so of M>3 everymonth. For two years the activity concentrated alongthe 2001 rupture zone of 40kmx40km with large slip.Subsequently, the hypocenters expanded to nearbyareas along different faults in E-W direction (more


82 22 - 24 January, 2011

towards E) becoming 70kmx50km, 100kmx75km and125kmx75km by 2003, 2004 and 2006, respectively.By 2008 the area further expanded to 200kmx80kmcovering South Wagad and Banni faults. Additionallythe epicentral area expanded by 60 km towards NEto Gedi fault by 2006. Moreover, the activity alongthe Allah Bund and Island Belt faults has alsoincreased, making most of north and east Kachchharea of 250km x150km active by 2008 with M<5shocks.

The activity had also spread towards south toSaurashtra: 120km by 2006 and 200km by 2007 alongseveral small faults in Jamnagar, Junagadh, Porbandarand Surendranagr districts. At three sites the activityis in the form of sequences with largest shocks ofM~ 4 to 5 and several hundreds of Me”0.5 shocksrecorded on local networks. Only two suchsequences were reported earlier during 1938 at Paliadin Bhavnagar district and during 1986 in Valsad, southGujarat.

The shear deformation for adjustment process inBhuj earthquake zone is now negligible as deducedfrom only 2-3 mm/yr movements of GPS stations.Moreover, the activity after 2001 earthquake can’tbe explained by Coulomb stress increase as the NEexpansion to Gedi area is in the zone of decreasedstress, though the EW expansion was as predicted.The viscoelastic process appears to be the plausiblemechanism for long distance and delayed triggeringof earthquakes by migration of stress pulsegenerated by 2001 earthquake with diffusion ratesof 5-30 km/yr or area growth of 4000 sq.km/yrcontributing stress vertically upwards from lowercrust and upper mantle to distances of 200km in 6years.

S10_P1

Active deformation and lithotectonic model ofSaurashtra Horst, Gujarat, India.

Girish Ch. Kothyari1*, Mukesh Chauhan1, R.K. Dumka1, A. K. Gupta1, Vikas Kumar1, B. K.Rastogi1 and S. K. Biswas2(1*Institute ofSeismological Research, Gandhinagar 382009,

Gujarat, India., 2 Flat no. 201 C-Block, ISM House,Thakur Village, Kandivali (E) Mumbai 400101, India)

Western margin of India is characterized by a riftedvolcanic continental margin. It extends from Kachchhin the northwest to Cape Comorin in the southeast.Saurashtra region of Gujarat, located in westernmargin of Indian shield, evolved as a founderedcontinental block. Saurashtra is seismically one ofthe active regions of Gujarat and has experiencedlow to moderate magnitude earthquakes in the recentpast. A lithosphere model is presented here usinghistoric and recent seismic events and available 2DBouguer gravity data. Seismic events were analyzedusing Gutenburg-Richter frequency-magnitudedistribution and b-value has been estimated tocharacterize the seismotectonic environment forSaurashtra region. The crustal movement ofSaurashtra has been estimated using GPS networkof Institute of Seismological Research (ISR). 2DBouguer gravity data have been correlated withmorphotectonic features in order to understand therelationship between gravity data and differentgeomorphic units. High gravity values in the centralpart of Saurashtra and low values on the north andsouth confirms horsts structure of Saurashtrainvolving basement block uplift. Several prominentlineaments are identified (Mishra et al., 2001).Distribution of historical seismicity as well as recentearthquakes and their aftershocks along prominentlineaments suggests presence of active faults alongthese trends. Concentration of hypocenters close tothe known plutonic bodies suggests that these highdensity bodies perhaps acted as stress barrier forearthquake generation. It appears that even deepseated magma in the lower crust is the source of theplutonic bodies injected through the existing faults.Correlation of all the data set validates thisinterpretation. Accumulation of strain beneathSaurashtra seems to be mainly controlled by faultsalong the flanks of plutonic bodies which generatesrecent earthquakes.

8322 - 24 January, 2011


S11_C1

Spatial Distribution of Scatterers in the Crustof Kachchh Region, Western India by Inver-sion Analysis of Coda Envelopes.

B. Sharma1 (E-mail: [email protected]), E.Carcolé2, A. Ugalde3 and B. K. Rastogi1

(1Institute of Seismological Research, Raisan,Gandhinagar-382009, India., 2 Universitat Politècnicade Catalunya, Dept. Enginyeria del Terreny,Cartogràfica i Geofísica, Jordi Girona 1-3, Edifici D2,08034 Barcelona, Spain., 3 Institut Geològic deCatalunya, Balmes, 209-211, 08006 Barcelona, Spain)

The three-dimensional spatial distribution of relativescattering coefficients is estimated in the Kachchhregion, western India, by means of an inversiontechnique applied to coda wave envelopes. Dataused consist of selected vertical-component,broadband recordings from 438 earthquakes withmoment magnitudes Mw ranging from 1.6 to 4.2 andepicentral distances up to 235 km recorded by theInstitute of Seismological Research (ISR) seismicnetwork. The results of the inversion analysis yieldrelative scattering coefficient estimates between ~1.3and ~0.8. Most of the analyzed region reveals smallspatial perturbations of the scattering coefficient of

the order of , thus suggesting a uniform distributionof scattering coefficients in the lithosphere beneathKachchh region for the scale length of the analyzedfrequencies between 1 and 2 Hz. This uniformity isbroken by the presence of some strong scatteringareas distributed in several clusters through theregion. A clear picture of the Moho in this region isimaged at average depths between 32 and 42 km.Also it is clear that in the Kachchh region the Mohodiscontinuity is highly disturbed maybe due the highvelocity body in the lower crust and upper mantlewhich is consistent with similar studies in the samearea. According to the outcome of the present studythis high velocity body, maybe having heterogeneityitself, has an irregular shape and extended in thearea throughout which is the reason of having morerelative scattering coefficient in the whole region.

S11_C2

Moho Depth Variation in the Shillong-MikirHills Plateau in North Eastern Region of IndiaEstimated From Reflected and ConvertedWaves

Saurabh Baruah (E-mail: [email protected]);Dipok K. Bora (Geoscience Division,CSIRNorth-East Institute of Science andTechnology,Jorhat-785 006, Assam, India)

S11: Earth’s Interior, Structure and DynamicsConvener : M.Ravi Kumar

THEMEOur understanding of the Earth as a dynamic system has primarily evolved owing todevelopment of new incisive tools to probe the Earth’s interior from the crust to core,tremendous strides in acquisition of high quality data from dense observational networkscoupled with enhanced computational power. Multidisciplinary knowledge accrued fromhigh resolution studies of the continental lithosphere, nature and deformation ofsubducting slabs, physical and thermal state of the mantle transition zone, the lowermostmantle region and the inner core in conjunction with mineral physics experiments iscontinually refining the forefront of knowledge thereby unveiling the fundamental globaland regional scale dynamic processes of our planetary interior. This session is intendedto focus on our current knowledge of the deep structure, evolution and dynamics of thestable continental interiors and actively deforming plate boundary regions in diversetectonic settings by bringing together researchers from a wide variety of disciplines fromactive and passive seismology, GPS geodesy, geodynamics, geochemistry, Magnetotelluricsand mineral physics. Contributions specific to the evolution of the Indian shield and itsplate boundary regions like the Himalaya, Burma and Andaman arc regions areparticularly welcome.


84 22 - 24 January, 2011

Distribution of Moho depth is estimated in Shillongand Mikir Hills Plateau of northeastern India usingtravel time differences between reflected P (PmP),S (SmS), P to S, S to P converted waves at theMohorovièiæ (Moho) discontinuity and the first P andS arrivals using 203 local earthquakes recorded byregional seismic network. The Moho depth wasestimated using model by Nakajima (PEPI 130:31-47, 2002), with considered epicentral distance rangedfrom 70 km to 250 km. Moho depth at reflection/conversion point obtained by assuming a flat Mohoand correlation of the results with geotectonics ofthe region are described in this paper. The reflectionand conversion points are uniformly distributed inthe study area which is mainly controlled by thegeometry of the events and locations of the stationsused in this study. A total of 966 reflected (PmP andSmS) phases arrival times from the seismograms of180 numbers of shallow earthquakes and 70converted (PS and SP) phases arrival times from 23intermediate depth earthquakes are used. Themagnitudes of the analyzed events range from 2.1to 4.3 and the focal depths of 180 events rangebetween 0 to 30 km while 23 numbers of eventsrange between 38 to 49 km. For PmP phase, thiscould be identified from 0.5 to 2.8 sec after the firstP-arrival. In case of SmS phase, the arrival timesare observed within 1.0 to 3.5 sec after the first S-arrival.The usage of converted phases in addition toreflected phases reduces the rms of residuals oftravel times from 0.351 sec to 0.332 sec after fiveiterations. It is observed that the Moho is thinnerbeneath the Shillong Plateau about 33-35 km and isthe deepest beneath the Brahmaputra Valley to thenorth about 39-41 km, deeper by 5-6 km below theShillong Plateau. The study indicates thinnest crust(~33 km) in the western part of the Shillong Plateauin the Garo Hills region.

Key words: Reflected waves. Converted Waves.Moho discontinuity. Shillong-Mikir Hills Plateau.Northeast India.

S11_C3

Seismic signatures of volcanism in the uppermantle beneath NW DVP.

G. Mohan* (E-mail: [email protected]), M. RaviKumar+, Pankaj Kr. Tiwari, G. Surve, D.Saikia+ and Praveen Kumar (*Department of

Earth Sciences, Indian Institute of TechnologyBombay, Powai, Mumbai – 400076.,+NationalGeophysical Research Institute, Uppal Road,Hyderabad – 500007.)

Teleseismic P receiver function study was done toinvestigate the upper mantle discontinuities beneathnorthwestern Deccan Volcanic Province (NWDVP) of India, encompassing the Saurashtra horst,Kutch, Cambay and Narmada rifts, Aravalli cratonand the offshore region of the Gulf of Cambay. Over1500 high quality receiver functions from 438 eventsrecorded by 9 broadband stations are utilized for thispurpose. The arrival times of the P410s and P660sphases are observed to be delayed at most stationsby H” 1-1.4s relative to times predicted by theIASP91 velocity model. However, the difference inthe P410s and P660s times corresponds to the globalaverage of 24s suggesting a normal mantletransitional zone structure. Explaining a delay of 1 –1.4s requires a reduction in the shear wave velocityof the upper mantle by 1-1.4 % with respect to theIASP91 velocity model. The anomalous delays arepossibly associated with a thin lithosphere coupledwith thermal/compositional variations in the shallowupper mantle beneath NW DVP. Interestingly, thepresent results are in stark contrast to a normalunperturbed mantle beneath DVP, south of Narmadarift, imaged using a similar technique. Similarly,indications for a normal upper mantle beneath theAravalli craton are observed, suggesting that thelithosphere beneath the cratons remain largelyunperturbed by the Deccan magmatism. Contrastingseismic signatures over the rifted and stretchedlithosphere of NW DVP and the undisturbed cratonsof Aravalli and South central DVP respectively, arepossibly linked to the flow pattern of the upwellingmantle material which is likely to be influenced bythe variations in lithospheric thickness. Thelithospheric architecture coupled with the reactivationof preexisting rift systems appears to have facilitatedthe eruption of Deccan basalts, whose sourcesignatures are still retained intheupper mantlebeneath NW DVP.

Key Words: Deccan volcanic province, low velocity,mantle discontinuities, Receiver functions

8522 - 24 January, 2011


S11_C4

Crustal Structure and Upper MantleDeformation in Eastern Himalayan Syntaxis:Derived from Receiver Function Analysis andShear Wave Anisotropy Study

Devajit Hazarika (Email: [email protected]),B.R. Arora (Wadia Institute of HimalayanGeology, Dehradun 248 001, India)

At the eastern end of the extended Himalayan arc,the east-west trending Indian plate seems to swervesaround Namcha Barwa antiform basement massifto connect to the elongated Indo Burmese arc toform the Eastern Himalayan Syntaxis (EHS). TheEHS is viewed complex triple junction that joins Indianand Eurasian plates with the northern end of theBurma platelet. The present paper is an attempt toimage the crustal and lithospheric structure ofnortheast part of Indian plate in the EHS based onreceiver function analysis of teleseismic earthquakesrecorded by a linear array of 11 broadband seismicstations established along the Lohit valley, cuttingacross eastern most part of the syntaxis. Thereceiver functions show an azimuthally varyinglithosphere structure in the region. The majority ofreceiver functions for the events of NE back azimuths(30o to 90o) do not show clear Moho convertedphase (Ps) depicting a very complex structure ofthe crust and upper mantle. In contrast to it, receiverfunctions from other back azimuths clearly showsMoho converted phase. The time section plot of radialreceiver functions from all the stations shows adipping structure of Moho towards east and north.The inverse and forward modeling of receiverfunctions yield S-wave velocity profiles marked bynear surface and intra-crustal low velocity zones.The results obtained from modeling confirm thegradual increase of Moho depth in the NE-SWprofile, from ~45 km at Brahmaputra valley (nearMahadevpur) to ~63 km further east of Tiddingsuture zone (near Walong). The dipping structure ofthe Moho to the north and east is consistent with theunderthrusting of the Indian plate beneath Eurasiaplate to the north and beneath Burma platelet to theeast. The absence of Moho converted phase for theNE back azimuth support the indenter hypothesiswhere due to the intense crust mantle interaction,

the character of Moho is lost beneath the syntaxis.

The upper mantle deformation pattern in EHSis also studied using shear wave (SKS phase)splitting technique which reveals considerablestrength of anisotropy with delay time 1.2-1.9s andE-W orientation of fast axis direction in most of thestations. The E-W trend of fast polarization directionis in favor of the fact that lithospheric strain inducedby Indo-Eurasia collision is a primary cause ofexisting anisotropy. However, deviations from thisE-W trend in some stations near Tidding Suture Zoneindicate the influence of local (NW-SE directed)tectonic feature beneath the stations. Discrepancyof E-W trend of fast axis direction with present daycrustal movement of NE India (NE directed)indicates that the crust and mantle in the region maynot be completely coupled. The predominant E-Wfast axis direction indicates the direction of mantlestrain that continues beyond Walong thrust andconnects to the N-S dominated mantle strain regimein Sichuan, SE Tibet. Although further studies areneeded to establish the nature of transition in moredetails fulfilling the geophysical data gap betweenthese two regions, but we assume that it reflects atransition from collision controlled deformation in NEIndia to deformation influenced by other forces inSE Tibet.

S11_C5

The signal of transition-zone anisotropy in thenormal mode coupling: Results fromobservations at Tibet and Taiwan.

Xiao-gang HU (E-mail: [email protected]),Xiao-guang Hao (E-mail: [email protected]) (KeyLaboratory of Dynamic Geodesy, Institute ofGeodesy and Geophysics, Chinese Academy ofSciences.)

We investigated normal mode couplings at Tibetand Taiwan island after seven earthquakes ofMw>7.8. We show that significant anomalouscoupling of 0S20-0T21, 0S24-0T24 and 0S25-0T25 areoften observed in the early part of verticalcomponent records after some large earthquakes.For example, after the 2001 Bhuj earthquake,coupling pair 0S24-0T24 was observed at the LSAstation (located at Lhasa, Tibet). The coupling


86 22 - 24 January, 2011

processes are characterized by coupled spheroidalmodes having anomalous small vertical amplitudesbut very large radial amplitudes. We note that stronganomalous couplings are often observed at TaiwanIsland, but not any one is observed at Okinawa(Japan) stations at the same time, even thesestations are less 200 km from Taiwan coastlines.Local anisotropy structure rather than Earth rotationseems more likely the cause of these anomalouscouplings. According to our estimation of couplingsensitivity kernels using model of mantle anisotropy,coupling of 0S20-0T21, 0S24-0T24 and 0S25-0T25 showpeak sensitivity to azimuthal anisotropy at 400–600km depth. Our findings suggest that local azimuthalanisotropy structures exist in the transition zonebeneath Tibet and Taiwan. For Taiwan Island, thebreak-off of the east-dipping Eurasian slab beneaththe Taiwan orogen is responsible for the formationof mid-mantle anisotropy. At Tibet, Indianlithosphere is subducting below the Asianlithosphere. The location of the final slab break-offis at about 400~600 km depth beneath theHimalayan-Tibetan orogen, which is responsible forthe formation of transition zone anisotropy.

S11_C6

Surface wave tomography across the Indianshield, Indo-Gangetic Plains and the Himalayanregion using ambient noise correlationtechnique.

N. Purnachandra Rao1, Peter Gerstoft2,D. Srinagesh1, M. Ravi Kumar1,Ch.Nagabhushan Rao3 and B.K. Rastogi3

( 1National Geophysical Research Institute,Council of Scientific and Industrial Research,Uppal Road, Hyderabad 500 007, India. 2MarinePhysical Laboratory, Scripp’s Institution ofOceanography, University of California, SanDiego, La Jolla California 92093, USA., 3Instituteof Seismological Research, Gandhinagar, Gujarat382009, India.

The Indian tectonic plate is known to beunderthrusting beneath the Himalaya-Tibetan plateauleading to a doubled crust – a feature unique to thiscontinental collision zone. Major international effortshave gone into comprehending the structure andevolution of the region with the help of active and

passive seismic experiments like PASSCAL,GEDEPTH, INDEPTH, HIMNT andNAMCHABARWA. However these studies weremostly confined to parts of Himalaya and the Tibetanplateau region to the north, due to non-availability ofseismic data from the Indian region. In the presentstudy we apply the ambient noise correlationtechnique to noise data recorded by about 50broadband seismic stations from the Sikkim andIndo-Gangetic networks near the eastern and centralHimalaya respectively, the Godavari network in theIndian shield region and the seismic network of theInstitute of Seismological Research in the north-western India. Ambient noise time series of 5 monthsduration between station pairs are cross-correlatedto obtain Green’s functions for over 1200 inter-station paths. It is found that the Indian subcontinentis characterized by a typical asymmetric, one-sidedGreen’s functions indicating inhomogenousdistribution of noise sources in the region, particularlya strong directionality towards south-southwest inthe Indian Ocean. Group velocity measurements atperiods of 10, 20, 40 and 50 seconds are used fortomographic inversion of travel times to get thevelocity variations corresponding to the upper, middleand lower crust, and also the uppermost mantlestructure. Variations in shear wave velocity andcrustal thickness are found in the Indian shield region,the Indo-Gangetic plains and Himalaya, with clearanomalies delineating the low velocity alluvial andsedimentary zone in the Indo-Gangetic plains and ahigh velocity lower crust corresponding to the Son-Narmada and Godavari rift valley zones in the Indianshield.

S11_C7

Anisotropy of the Indian crust from splitting ofPs phases from the Moho

Narendra Kumar (E-mail: [email protected]),Saifur Rehman, M. Ravi Kumar, Arun Singh,N. Purnchandra Rao (National GeophysicalResearch Institute, Hyderabad-500 007, India)

The Indian lithosphere is exemplified by its diversetectonic activity. This is highly deformed due to thebreakup of Gondwanaland since the Precambriantimes. In this study, we estimate the crustalcontribution of anisotropy within the Indian

8722 - 24 January, 2011


subcontinent through splitting of P-to-s conversionsfrom the Moho, isolated using the conventionalreceiver function technique. Shear wave splittinganalysis of the receiver functions from 51broadband seismic stations located on variousgeological units sited on the Indian shield yielded183 measurements. Our results reveal that the delaytimes lie between 0.20sec and 0.40sec consistentwith those obtained from other regions globally. Thedistribution of crustal anisotropy within the Indiancontinent appears very complex with a tilted axisof anisotropy. The orientations of fast polarizationazimuths at individual stations although scatteredproduce an average that is consistent with the straindue to the Absolute Plate Motion of the Indian plate,akin to those found from previous SKS/SKKSsplitting measurements.

S11_P1

A Comparative Study on Seismic Wave Attenu-ation Characteristics of Koyna, Chamoli andGujarat Regions

Babita Sharma1 (E-mail: [email protected]),Dinesh Kumar2, S.S.Teotia2 and B.K.Rastogi1

( 1Institute of Seismological Research,Gandhinagar, Gujarat, India. 2Department ofGeophysics, Kurukshetra University, Kurukshetra,India.)

The attenuation of seismic waves in a region iscaused by geometrical spreading, scattering due toinhomogeneities in the media, inelasticity andmultipathing. The attenuation characteristics of aregion differ from the other because of differentlevels of heterogeneities and inelasticity present.Therefore it is interesting to compare theattenuation characteristics of the regions withdifferent geology and tectonic set up. Theattenuation characteristics of three Indian regions,namely Koyna region, Kachchh region and Chamoliregion have been compared and correlated withtheir tectonic set-up in the present study. Out ofthese three regions Koyna region shows reservoirinduced seismicity alongwith the tectonic reasons.The Chamoli region is in the Himalayas which showsinter-plate seismicity while Kachchh region showsintra-plate seismicity. These regions are also

important from seismic hazard point of view. Thefrequency dependent relationships for quality factor(Q) estimated using different parts of theseismograms are available. These availablerelations have been used in the present study. Thefrequency dependent attenuation relationshipsavailable for three regions are as follows:

Koyna region Qα=(59 ± 0.5)f(1.04±.04), Qβ= (71 ±1.1)f(1.32±.08) & Qc= (117 ± 2)f(0.97±.07)

Chamoli region Qá = (44 ± 1)f(0.82±.04) & Qâ = (87± 3)f(0.71±.03)

Kachchh region Qá=(77±2)f(0.87±.03),Qâ=(100±4)f(0.86±.04) & Qc=(148±3)f(1.01±.02).

The comparison attenuation characteristics of threeregions gives better idea about the heterogeneitiespresent in these seismically important regions.

S11_P2

Inversion of Seismic Intensity Data for theDetermination of Three-Dimensional Attenu-ation Structures in Saurashtra, Gujarat (India)

Babita Sharma1 (E-mail: [email protected]),Anand Joshi2, Sumer Chopra1 andB.K.Rastogi1 (1Institute of SeismologicalResearch, Gandhinagar. 2Department of EarthScience, IIT, Roorkee.)

Three dimensional attenuation structure of theSaurashtra region which lies in the western part ofIndian subcontinent is determined from present study.The region is a stable region in terms of seismicityalthough it has shown considerable events ofmagnitude ranging 0.5 to 5 in recent past. The 2001Bhuj earthquake has perturbed the stress in the regionand the activity in terms of earthquakes has increasednear Junagadh, Jamnagar and Surendranagar areasof Saurashtra. Most of the Saurashtra falls in zoneIII in the Seismic zoning map of India excludingnorthern part which falls in zone IV due to proximitywith Kachchh. The historical isoseismal data is usedto obtain three dimensional attenuation structure ofthe region based on Q values using damped leastsquare inversion scheme. For this purpose theisoseismal data for four earthquakes that haveoccurred in Saurashtra in the past having magnituderanging from 4.0 to 5.0 have been used. The obtained


88 22 - 24 January, 2011

Q structure for Saurashtra can be valuable input forthe purpose of seismic hazard zonation.

S11_P3

Seismic evidences for Underplating andUplifted Crust beneath the NorthwesternDeccan Volcanic Province of India fromReceiver Functions.

K. Madhusudana Rao*(E-mail:[email protected], [email protected]),M. Ravi Kumar#, B. K. Rastogi* (*Institute ofSeismological Research, India. #NationalGeophysical Research Institute (Council ofScientific and Industrial Research), India.

The northwestern Deccan Volcanic Province in Indiaand associated pericratonic rift basins werereactivated during several stages of India’s northwarddrift after the break-up of Gondwanaland during thelate Triassic-early Jurassic and post collision withAsian plate. In this study, we attempt to deciphercrustal thickness and average crustal Vp/Vs ratiosbeneath the region using the slant stacking analysisof 2776 teleseismic receiver functions from a regionalnetwork comprising 46 broadband seismic stationssited on diverse tectonic environments. Most of thereceiver functions reveal clear negative phasesbetween 0-5 s & 5-10 s after the first arrival. Resultsfrom slant stacking analysis reveals the Moho depthsare varying from (32.8 – 43.3 km) in the Kutch region,(30.8 - 37.6 Km) in the Saurashtra region, (27.1 -34.3 Km) in the Cambay basin, (28.0 - 35.5 Km) inthe Narmada region and (40.3 – 41.3 Km) in thenorth and eastern part of Cambay basin. HigherMoho depths are found under the SE part of KMU(~43.3 km) and Wagad uplift (~42.8 km) in Kutchregion due to mass deficiencies from thickening ofcrust caused by isostatic overcompensation and alsoin the eastern part of Cambay basin (~41.3 km).Lower Moho depths are found beneath Cambay &Narmada rift basins and coastal areas. The shallowercrust is also observed in the region surrounded bythe extension of western limb of the ProterozoicArravalli trend in Saurashtra, its eastern limb andthe Narmada fault in the south. This region isobserved lower Moho depth of 27-34 km ascompared to the surrounding regions (36-41 km)implying 3-7 km crustal upliftment. The positive

buoyancy and uplift (vertical block movement) maybe attributed to thermal influxing from the re-unionplume after Gondwana breakup. High Vp/Vs ratiosare detected beneath Kutch (1.8-2.03), coastal areasof Saurashtra (1.79 – 1.99) and NE part of Cambaybasin (1.82-1.97) indicating mafic/ultra mafic crustproviding evidence for the extensive magmaunderplating beneath these regions. At all otherstations, the Vp/Vs ratios are in the range of (1.70 –1.76) which appears to be felsic with dominance ofQuartzite, similar to the global average forPrecambrian shields. The Moho depths derived inour study are consistent with previous estimates fromgravity and deep seismic studies (DSS). Thecorrelation coefficients between our Moho depthvalues and their estimates are 0.81 for Gravity and0.84 for DSS. The errors in the slant stacking analysisare estimated using bootstrap re-sampling technique.The errors for Moho depth and Vp/Vs are in therange of ± (2-4) Km and ± (0.1-0.2). Combined withhigh regional heat flow, mid-crustal layers of highelectric conductivity, the large intra crustal S-wavevelocity reduction and the high average crustalPoisson’s ratios are consistent with partial melt whichmay be related to the process of magmaticunderplating in the lower crust beneath Kutch,coastal areas of Saurashtra and NE part of Cambaybasin.

S11_P4

Shear wave splitting beneath the NorthwesternDeccan Volcanic Province: Evidences forlithospheric and APM related strain.

K. Madhusudana Rao*(E-mail:[email protected], [email protected]),M. Ravi Kumar#, Arun Singh#, B. K.Rastogi*(*Institute of Seismological Research,Gandhinagar – 382 009, India.,#NationalGeophysical Research Institute, Hyderabad-500007, India.)

The northwestern Deccan Volcanic Province in Indiahas witnessed several tectonic episodes resulting inthe formation of rift zones, wide spread magmatismand deep seated faults that are host to some deadlyintraplate earthquakes. In this study, we attempt todecipher the mantle deformation beneath the regionusing the SKS splitting technique applied to highquality data from a regional network comprising 36broadband stations sited on diverse tectonicenvironments. The first measurements of 280 (207

8922 - 24 January, 2011


SKS and 73 SKKS) splitting parameters from 73earthquake sources reveal two major trends, onecoinciding with the absolute plate motion (APM) andthe other with the strike of the local geologic fabric.The Kutch rift, southern part of Saurashtra, southernpart of South Gujarat and northern and eastern sideof Cambay rift, reveal characteristics of ENE-WSWoriented anisotropy which is sub parallel to the DelhiAravalli fold belt. This characteristic suggests thatthe mantle in these regions retains the history ofPrecambrian deformational structures andsubsequent deformation episodes. Imprints of theReunion plume (that is widely regarded as the sourceof volcanism) are absent in terms of signatures ofan asthenospheric radial flow. Also, our observationsare not consistent with anisotropy created by riftingprocess at Narmada and Cambay rifts. With theexception of large delay times (ät=1.8s) at fivestations within the Kutch rift which may be due toaligned melt pockets within mantle-lid, the delaytimes at all other stations are close to 1s, similar tothe previous estimates from other parts of the Indianshield. Previous measurements of shear waveanisotropy in the northwestern DVP have been verysparse to comprehend the mantle deformation in thisregion of tectonic complexity. SKS splittingmeasurements restricted to data from only twobroadband stations (BHUJ, DHR) as a part of thecontinental scale study of the Indian shield anisotropy(Kumar, M.R and A. Singh, 2008) reveal small delaytimes of 0.6±0.3s and 0.9±0.5s with fast polarizationazimuths of 62±26.5° and 30±22.5° for stationsBHUJ and DHR respectively.

S11_P5

Evaluation of the crustal structure of the IndusBlock up to Saurashtra using GA Inversion ofSurface Wave Dispersion

Vishwa Joshi (Email: [email protected]),Sandeep Aggarwal, Om Bihari, S NBhattacharya and B. K. Rastogi (Institute ofSeismological Research, Gandhinagar-382009,India)

We have computed group velocities of thefundamental mode Love and Rayleigh wave usingearthquake of magnitude 5.2 MW (Lat: 39.50, Long:73.81) recorded at 7 stations of Saurashtra [Amreli

(AMR), Bhavnagar (BHV), Lalpur (LAL), Morbi(MOR), Rajkot (RAJ), Surendranagar (SUR), Una(UNA)] by seismic network of Institute ofseismological research, Gujarat (India).The periodof the group velocity data ranges from 6 to 60 sec.The dispersion curves have been inverted for crustalstructure using Genetic Algorithm. It gives theaverage crustal structure along the path. We haveevaluated crustal structure of Indus block up tosaurashtra having 43.61 km thick crust and 4.53 km/sec S-wave velocity. Whereas previous study ofIndus block up to Bhuj indicates 44.2 km thick crustwith 4.39 km/sec S-wave velocity. According to theseresults, we found that Kutch region is thicker thensaurashtra region.

Key Words: Dispersion, Genetic Algorithm,Saurashtra

S11_P6

Shield like lithosphere of the lower Indus basinEvaluated from observations of surface wavedispersion.

Mukesh Chauhan1

([email protected]), Arun K.Gupta1, Rashmi Pradhan1*, G. Suresh 1**, andS.N. Bhattacharya 1***(1Institute of SeismologicalResearch, Raisan, Gandhinagar -382009, (Gujarat)India., 1*Ministry of Earth Sciences, New Delhi,India. 1**Seismology Division, India MeteorologicalDepartment, New Delhi-110003, India.


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1***Department of Geology, University of Delhi,Delhi 110007, India)

The lithospheric velocity structure of the lower Indusbasin has been evaluated through inversion offundamental modes of both Love and Rayleighwave group velocities from the broadband recordsof a seismic network maintained in Gujarat byInstitute of Seismological Research. We haveconsidered three clusters of wavepaths A, B andC that are mainly across the lower Indus basin fromsouth to north; the wavepaths of A mainly crossthe continental self and the wavepaths of B and Cpass through the lower Indus basin. The measuredgroup velocities correspond to periods of 5 to 90sec for Rayleigh waves, and 5 to 115 sec for Lovewaves. These data sets resolve the structure ofthe lithosphere through a nonlinear inversion basedon a genetic algorithm with a wide solution space.The mean and standard deviation of the 70 acceptedsolutions for each of these three clusters provide

the 2-D structure for the lower Indus basin fromsouth to north. The sediment consists of two layerswith total thickness from 5.7 to 6.6 km increasingnorthward. The crustal thickness also increasesnorthward from 32.9 (cluster A) to 39.7 km (clusterC) in the lower Indus region. This northwardincrease of crustal thickness suggests that the regionis undergoing some sort of dynamic crustaladjustment, perhaps as a result of a paleo-geographic environments or thermal subsidencenear the Moho boundary. The S-wave velocitybelow the crust varies from 4.55 to 4.59 km/sec,which is close to the corresponding velocity 4.60km/sec of the Indian shield region to the east ofthe Aravalli range. The thicknesses of thelithosphere, as well as the velocities of theuppermost mantle of the lower Indus plain, aresimilar to that of the Indian shield, but different fromthose of middle Indus basin. This differencesupports the hypothesis of continental breakups inthis region.

9122 - 24 January, 2011


S12_I

Weak Mantle Lithosphere in Kachchh, IndiaProbed by GPS, InSAR and GravityMeasurements following the 2001 BhujEarthquake

D. V. Chandrasekhara,* and RolandBürgmannb(a*National Geophysical ResearchInstitute (CSIR), Hyderabad, India.,bDepartmentof Earth and Planetary Science, University ofCalifornia, Berkeley, USA.)

The Bhuj earthquake of January 26, 2001 inKachchh, India is the largest event (Mw=7.6) in thelast 50 years in a continental shield region. We useGPS, gravity and InSAR measurements and modelsof postseismic deformation caused by the Bhujearthquake to assess the viscous strength of the lowercrust and upper mantle. To fit the observeddisplacements we model the relaxation response ofa layered viscoelastic earth to the earthquake anddetermine optimal values for the thickness of anelastic plate and the viscosity of an underlyingviscoelastic half-space. The best-fit elastic layerthickness is ~ 34 km, which is close to the localcrustal thickness. We find an upper mantle effectiveviscosity increasing from 3 x 1018 Pa s based ondeformation in the first 6 months to 2 x 1019 Pa sconsidering data spanning 6 years after themainshock. The presence of relatively weaklithospheric mantle in western India is consistent withresults from independent seismological andpetrological studies that show reduced seismicvelocities in the top 250 km and early Cenozoicemplacement of magma plutons, indicating an

abnormally hot upper mantle beneath theeasternmost extent of Kachchh rift basin. The GPSdata do not require a viscous lower crust butconstrain a lower bound viscosity of 1020 Pa sindicating a strong lower crust. Using our best fitupper mantle and lower crust viscosities, we findthat the postseismic contribution of viscoelasticrelaxation to present day horizontal GPS velocitiesare small; d” ~3 mm/yr.

S12_C1

SAR Interferometry detects post-seismicground deformations related with 2001 BhujEarthquake.

Arun K. Saraf (Email: [email protected]),J. D. Das*, Ankita Biswas, Vineeta Rawat,Kanika Sharma & Yazdana Suzat (Department ofEarth Sciences, Indian Institute of TechnologyRoorkee, ROORKEE – 247667, INDIA.*Department of Earthquake Engineering, IndianInstitute of Technology Roorkee, ROORKEE –247667, INDIA).

The ground deformations in the Bhuj earthquakeaffected region have been analyzed using two InSARdata pairs (2003-2004 and 2004-2005 years) coveringan area east of Bhuj constituting a near flat terrainnorth of Kutch Mainland Fault. Resultinginterferograms displaying well formed fringesenabled to draw interesting observational inferencestowards the ground deformation of the study area.The analysis of interferogram of the year 2003-04suggests upliftment of about 8 cm (surface motiontowards the satellite) around Kunjisar village and also

S12: Crustal Deformation through GPS and InSAR StudiesConvener : V.K.Gahalaut

THEMEUnderstanding the process of occurrence of earthquakes in the plate interiors has alwaysbeen a great challenge for geoscientists. These regions are characterized by very lowstrain rate and hence the earthquake recurrence intervals are generally very large. Suchregions become centers of large inhabitation and people tend to assume that the seismichazard in such regions is low. In such regions earthquakes occur as a “surprise” andcause relatively more damage, as compared to the earthquakes in the high seismic hazardregions where people are aware of high seismic hazard and take care in enforcing buildingcodes. The 2001 Bhuj earthquake is one such best example. Thus it is important tounderstand the strain rate, crustal deformation through earthquake cycle, mechanism ofcrustal deformation, crustal structure, rheology and earthquake occurrence processesin these regions. This session is aimed to focus such studies in the Kachchh and similarother regions of the world.


92 22 - 24 January, 2011

upliftment of 25 cm and 5 cm in the other two areasnorth of Kunjisar. Whereas, the interferogram imagebelonging to the year 2004-05 reveals subsidence ofabout 17 cm (surface motion away from the satellite)in Kunjisar area along with subsidence of about 28cm and 5 cm in the two areas north and northwestof Kunjisar respectively. Hence, between the years2003 and 2005 two different episodes of upliftmentand subsidence have been observed in the study area.The ground upliftment during 2003-04 probablyindicates last phase of ground deformation followedby the onset of subsidence during 2004-05 as therock volume involved in stress-strain processesbegan to experience relaxation phase.

Keywords: InSAR, Bhuj Earthquake, Deformation,Interferogram

S12_C2

Ten decades of GPS observations after2001Bhuj Earthquake: Possible postseismicmechanisms and processes.

C.D. Reddy1, P.S. Sunil1, Roland Bürgmann2,D.V. Chandrashekar3, Teruyuki Kato4 ( 1IndianInstitute of Geomagnetism, New Panvel, Navimumbai, India. 2Dept of Earth and PlanetarySciences, University of California, Berkely, USA. 3National Geophysical Research Institute, Hyderabad,India. 4. Earthquake Research Institute, TheUniversity of Tokyo, Japan)

Earthquakes cause static stress perturbation in theenvironing crust. Obeying rheological laws, this stressrelaxes in a time frame of months to years withspatial extent of few km to hundreds of km. Whilepost-seismic relaxation associated with major inter-plate earthquakes is irrefutable, it is rather difficultwith intraplate earthquakes. The Mw 7.6 Bhujearthquake on January 26, 2001 in Western Indiaconsidered to be an intraplate event and provides aunique opportunity to examine post-earthquakerelaxation processes far from plate boundaries.

To study the characteristics of transient post-seismicdeformation, six GPS campaigns were made at 14sites. The GPS dada have been analyzed to generatetime series of the position co-ordinates in east-west(EW), north-south (NS) and up-down (UD)components. The postseismic transients weredelineated after removing the inter-seismic and platemotions from these time series. Post-seismicdeformation has been observed at all the sites in the

study area. During 2001-2007, the site closest to theepicenter exhibited postseismic deformation of about30 mm and 25 mm in north and east componentsrespectively. More than 90% relaxation seems takenplace in first one year after the earthquake.

Both NS and EW components of the post-seismictransients can fit well to logarithmic and exponentialfunctions. Close to epicenter, the logarithmic functionfits well to initial duration, and exponential functionfits well to later duration. All the sites in epicentralregion exhibited significant stress relaxation in botheast-west and north-south components. Theremaining sites (falling east and west of epicentralregion) exhibited significantly diminished north-southrelaxation. The pattern of postseismic transientssupports the hypothesis that the Bhuj region is highlyheterogeneous with blocked structures. This regionalso spatially coincides with the aftershocks distributionfollowing the Bhuj earthquake, with better correlationparticularly with those after shocks with more than10 km depth. Rapidly decaying afterslip and poro-elastic mechanisms seem to be responsible for post-seismic relaxation in the vicinity of epicenter duringthe initial period subsequent to the Bhuj earthquake.Postseismic relaxation by viscoelastic mechanismseems to be operative almost in entire Bhuj region.

Key words: GPS, postseismic deformationtransients, stress relaxation

S12_C3

Studies on Seismic Behaviour and associatedTopographic Changes in NE India based onRemote Sensing data.

R. K. Sukhtankar*(E-mail:[email protected]), Umamaheswari A*,P. Pradeep Kumar*, T. J. Majumdar** andK. M. Sreejith*** (* Department ofAtmospheric and Space Sciences, PuneUniversity, Pune. ** Institute of SeismologicalResearch, Gandhinagar. *** Space ApplicationsCentre, Ahmedabad)

Convergence of the Indo-Australian Plates hasresulted in the tectonically and seismically activeHimalayan Mountain Chain, of which the North-EastIndia forms the easternmost extremity. The NEIndian region however constitutes the syntaxis ofthe convergence belt and therefore is relativelyseismically more active. Seismological data fromUSGS, ISC and IMD for the period from 1951 -

9322 - 24 January, 2011


2008 have been collected. Spatio-temporal plots ofepicentres have been made decadalwise, whichreveal the preferred distribution of epicentres,indicating the planes of weakness through which thecrustal stresses get released. These planes ofweakness are evidenced by the structural/tectonicfabric, in the form of lineaments, faults and thrusts.

Remote sensing data in the form of IRS- 1A, 1Cand 1D satellite imageries, have been examined overthe same region for the years 1988 - 2002. It revealedcharacteristic changes in the flow pattern of thestreams that originate at the base of the mountainfront, sudden deposition/removal of sediments. Suchan observation has been ascribed to spatio-temporaltrend of release of stresses.

These studies reveal the close correlation betweenepicentral distribution and changes in topographythrough time. It is, therefore, summarized that analysisof the remote sensing data coupled with the spatio-temporal distribution of epicenters that yield signaturesby way of topographic changes, may reveal theprobable area of impending major earthquake. It isfurther suggested that such studies, if applied to theBhuj region, which is a characteristic of rift tectonics,may help to decipher the probable areas where thecrustal stresses are getting accumulated andtherefore the future seismically active zone.

S12_C4

Crustal deformation mapping in Kachchh, Indiausing InSAR and GPS: Initial results.

K. M. Sreejith1* (E-mail:[email protected]) Phone: +9179 26914103), T. J. Majumdar2, B. K. Rastogi2,R. Dumka2, P. Choudhury2 and F.Bhattacharya2(1Geosciences Division, Marine,Geo and Planetary Sciences Group, EPSA,Space Applications Centre (ISRO), Ahmedabad-380015, India. 2Institute of SeismologicalResearch, Gandhinagar – 382009, India.)

Kachchh rift basin in Gujarat has been seismicallyactive since the historical period. The devastatingBhuj earthquake of 26th January 2001 is consideredas one of largest intraplate events. After a period ofquiescence, since 2006 the area became active withseveral earthquakes of magnitude >5 and numerouslow magnitude events. These are attributed to post-seismic relaxation of the region. We made an attemptto study the seismic deformation using differential

interferometry (DInSAR) aided with CornerReflectors and DGPS observations. We havegenerated and analysed ENVISAT ASARinterferogram with DGPS results of 3 permanentand 11 campaign stations in Kachchh during June2008 and October 2009. The signals related to thedeformation are not directly visible in theinterferogram due to decorrelation effects. Hence,only areas with coherence > 0.25 were consideredfor the analysis. A differential interferogram wasgenerated by removing the topographic phases whichwas later converted to displacement. Thedeformation map thus generated shows displacementof 0-50 mm along the line of sight of the satellite.DGPS data for a period of 2007-2009 show verylow deformation rates of about 1-3 mm/yr in thehorizontal direction whereas the vertical componentof deformation is as high as 13 mm/yr. The verticaldeformation from GPS projected along the line ofsight of the satellite has given comparable resultswith InSAR deformation. The deformation mapgenerated in the current study is limited to few areaswhere coherence is high. Nevertheless, the presentstudy reveals that InSAR can be an effective toolfor understanding the crustal deformation in Kachchhdue to its wider spatial coverage. We speculate thatthe inferred deformation rate may be resolved forthe Kachchh basin by analysing more SAR data atregular time intervals. However, the currentlyoperating SAR sensors like ENVISAT ASAR, ALOSPALSAR have very limited data availability overIndia.

S12_C5

The Tehri Dam, Uttarakhand: Crustal Strainand Implications in case of Reservoir InducedLoading

Swapnamita C. Vaideswaran(Email: [email protected]);Ajay Paul (Wadia Institute of Himalayan Geology,Dehradun)

The Tehri Dam Project is a prestigious and costlyirrigation and hydropower project. The 260.5 m highdam is built downstream from the Bhagirathi andBhilangana River confluence in the state ofUttarakhand, India. Concerns about the safety of thedam in the event of an earthquake had been raisedfollowing the Uttarkashi and Chamoli earthquakes.Despite all measures taken for the dam design safety,two apprehensions regarding, first, how will the dam


94 22 - 24 January, 2011

perform in case of an earthquake?, and second, willthe loading of dam with a full reservoir level of 830 mand live storage of 2615 million m3 induce anearthquake? The study of accumulation of strain inthe near vicinity of the dam is therefore much required.Using interferometric synthetic aperture radar(InSAR) the region around the reservoir has beenstudied prior to the filling of the reservoir so as toknow the already prevalent stress-strain scenarioaround the reservoir. The study was done usingENVISAR-ASAR satellite data. This initial study wasconducted to understand the nature of changes indifferent time frames, one month, six months and oneyear prior to the complete reservoir filling. Thedisadvantages of the Himalayan topography andrugged nature had to be dealt with. Further, vegetation,atmospheric effects also brought about loss ofcoherence in the image pairs. Different filteringtechniques when applied led to a better understandingof the processing of the data as well as the situationof the region around the dam. However, the constraintsof the topography and atmospheric artefact remainfor the region. The Goldstein filtering technique gaveappreciable results in this case. SAR data wasprocessed for the period 2003-05. The data for onemonth temporal resolution shows the best coherenceand the coherence retention for larger temporalresolution is difficult for the terrain. Based on ourseismic network around the region, the seismicity ofthe region was studied. The PGA calculated for eightdifferent stations for the years 2007-09, afterimpounding of the dam. The presence of dense seismicnetwork enhances estimation of accurate seismo-tectonic conditions due to the present scenario.

S12_C6

Satellite altimeter derived geoid/gravity and thelithospheric density anomaly along theconvergent zone of Sumatra-Andaman:Implications on the cessation of fault ruptureup to 14o N after 26 December 2004 Sumatra-Andaman earthquake

Rajesh S. (Geophysics Group, Wadia Insitute ofHimalayan Geology, Dehradun), Majumdar T. J(Institute of Seismological Research, Gandhinagar,Gujarat. E-mail: [email protected] )

The 26 December 2004 Sumatra-Andamanearthquake (Mw = 9.1 to 9.3) occurred along theconvergent plate boundary of the Indo-Australianand Southeastern Eurasian plates. This caused a

devastating Tsunami along the rim of eastern IndianOcean states, although it gave a rare opportunity tounderstand the dynamics of earthquake rupture alongthe convergent margins. An intriguing aspect of thisgigantic earthquake was the nature of propagationof fault rupture, its aerial extension and the slip rate.Many investigations1,2,3,5,9 showed that the rupturelength was more than 1400 km from the source andpropagated along the frontal arc of the Sumatra-Andaman subduction zone. But what caused thecessation of the rupture up to 14o N, notwithstandingthat the region had been known for obliqueconvergence where the Indian plate subductsbeneath the Andaman arc. The slow rupture of theSumatra earthquake in the Andaman region was alsoobserved4 as a consequence of subduction of theNinetyeast Ridge. The observed surfacedeformational structures as well as the terminationof fault rupture are explained in the light of how anisostatically compensating source body, which is ahotspot related under plated basal material of theNinetyeast Ridge, affected fault propagation,regional stress distribution and the convergence ofthe Indian plate.

We used the instantaneous sea surface heightmeasured by various satellite altimeter missions suchas ERS-1&2, GEOSAT and TOPEX to derive themarine geoid/gravity6,7 over the whole eastern IndianOcean. The isostatic compensation mechanism ofthe Ninetyeast Ridge, where it impinges the Andamantrench (between 7o to 18o N) have been studiedthrough geoid to topography, gravity to topographyand the continuation of gravity anomalies.Particularly, Geoid to topography ratio couldeffectively explain the compensations caused by longwavelength lithospheric mantle density anomalies.Moreover, its anomaly wavelength is sensitive to thedeeper viscous flow and hence easy to deduce thedynamics of density gradient flow existing betweenthe Ridge compensating body and the Andamanconvergent zone.

Our results (Rajesh and Majumdar, 2010) obtainedfrom geoid to topography ratio suggest that thecompensation depth of the Ninetyeast ridge vary from13 to 28 km at where it impinges the rupture terminatedAndaman trench. While at its northernmost regionlower average compensation depth of 8.7 ± 0.4 km isobserved. Gravity to topography kernel and the

9522 - 24 January, 2011


upward continued anomaly show relatively dense andviscous hotspot affected under plated basal materialas a prominent compensating body. The presence ofsuch an under plated basal material beneath the ridgejuxtapose to the Andaman collision zone had affectedthe regional lithospheric density gradient and hencethe crustal rheology. Thus it is evident that in the ridgetrench collision zone from 7o N to 14o N there exist astrong density gradient driven viscous flow in thelithospheric mantle between ridge compensating bodyand the subducted lithospheric slab. Such a densitybarrier can cause rapid dissipation of seismic energyand hence could arrest the propagation of fault furthernorth from 14o N.

References:

1. Ammon et al., 2005, Science, 308, p.11332. Banerjee et al., 2005, Science, 308, p.17693. Gahalaut et al., 2006, Earth Planet. Sci. Lett,

242, p.3654. Gahalaut et al., 2010, Geophys. J. Inter., 180,

p.11815. Lay et al., 2005, Science, 308, p.11276. Majumdar et al., 1998, Int. J. Rem. Sens. 19,

p.19537. Rajesh et al., 2004, Int. J. Rem. Sens., 25, p.28978. Rajesh et al., 2010, Mar. Geophys. Res., DOI

10.1007/s11001-010-9088-79. Shapiro et al., 2008, Geophys. Res. Lett., 35,

doi:10.1029/2008GL033381S12_P1

Post-seismic deformation associated with the2001 Bhuj Earthquake

Pallabee Choudhury1 (E-mail:[email protected]); J K Catherine2, RakeshDumka1, Sumer Chopra1, V K Gahalaut2 andB.K. Rastogi1 (1Institute of SeismologicalResearch, Raisan, Gandhinagar; 2 NationalGeophysical Research Institute, Hyderabad)

Post seismic deformations are going on in Kachchhregion, Western India due to relaxation process ofthe 2001 Bhuj earthquake. For monitoring the crustaldeformation in and around Gujarat, Institute ofSeismological Research (ISR) has deployed a totalof 25 permanent and 11 campaign GPS stationsstations starting 2006.

The velocities of 3 permanent stations and 8campaign stations run for 3 years show average

velocity of 49±1 mm/yr towards NNE with respectto ITRF05 frame which is same as expected fromplate tectonics. To estimate local deformation in thisregion, the Indian plate motion was subtracted fromthese measurements, taking ISR permanent station(ISRG) as reference. All sites show very smallmovement of the order of 2- 5 mm/yr. The stationLilpar (LLPR) in Wagad area exhibits a velocity ofabout 4 mm/yr towards SE. It appears that the Wagadarea may be moving towards east. Station Dudhai(DUDH) and Chandrani (CHAN) situated onhanging wall side of the 2001 rupture plane, showsnorthward movement conforming to the mainearthquake rupture. Stations on hanging wall sideindicate movement towards WSW conforming to themain-earthquake rupture.

Displacements of two ISR campaign stations, namelyDudhai (DUDH) and Amrapar (GIBF) for the period2006 onwards are computed. DUDH is close toDHAM station of IIG while GIBF is close to RATN.The IIG stations were run for the period 2001-2006.The reference station is Gandhinagar (ISRG) for ISRand Ahmedabad (AHMD) for IIG. Hence it ispossible to combine two data sets and infer themovement at these places from 2001 onwards. Therate of movement towards NW was fast at Dudhaiwhich is close to the epicenter. It exponentiallyreduced being 12, 6, 4 and 3 mm for four consecutive6 months periods of 2001-2002 and between 2-3 mm/yr at present. At Amrapar, 50 km north of 2001epicenter, the rate of movement was 1/3 rd anddecaying exponentially.

It has been observed that the aftershocks (Md”5) inthe source region of the 2001 Bhuj earthquake inthe Kachchh region are continuing and the seismicityhas expanded up to 60km NE of the 2001 Bhujearthquake aftershock zone in the last 9 years. Theshear deformation for adjustment process in Bhujearthquake zone is negligible being 2-3 mm/yr asderived from horizontal displacement of GPS stations.However, the rate of vertical displacement estimatedfrom the campaign GPS sites is exceptionally large.Maximum rate of displacement is ~13mm/yr. Thevertical movement and / or viscoelastic relaxation atlower depth levels appears to be the probablemechanism for long distance and delayed triggeringof the aftershocks.


96 22 - 24 January, 2011

S13_I1

On-land Kutch basin and its basementconfiguration from seismic refraction studiesand modeling of first arrival travel time skipsalong Jakhau-Mandvi-Mundra-Adesar profiles

B. Rajendra Prasad and Emeritus Scientist(National Geophysical Research Institute, UppalRoad, Hyderabad- 500 007, India)

The Kutch basin is one of the three (Narmada,Cambay and Kutch) major marginal rift basins thatare close to each other in western part of the Indiansubcontinent. The seismic refraction and wide-anglereflection data were acquired and a first ordervelocity structure of the Kutch sedimentary basinalong four profiles viz. Jakhau-Mandvi, Mandvi-Mundra, Mundra-Adesar and Hamirpur-Halvad isderived. Travel time skip phenomenon has beennoticed in the plots of record sections indicatingpresence of low velocity sediments. The 2-D velocity-depth models derived from these data sets revealeda Mesozoic sedimentary sequence sandwichedbetween Trap and Limestone layers, in some of theprofiles. Two thick low velocity layers (thatcorresponds early to late Mesozoic era) have beenidentified. These are dipping towards Mandvi alongJakhau-Mandvi profile. The early Mesozoic layerthat is thinning towards southeast is completelymissing in Mandvi-Mundra profile. It is also noticedthat the early Mesozoic Bhuj formation exists in thenorthern parts of the Mundra-Adesar and Hamirpur-Halvad profiles, where it directly overlies the graniticbasement.

The derived velocity-depth model suggests that thebasement is about 3 km deep near Jakhau andreaches a depth of about 6 km near Mandvi. Thelayered structure may correspond to the Tertiary,Trap, Late Mesozoic sediments and Mesozoiclimestone. The velocity-depth model obtained inKutch is very similar to earlier derived model forJamnagar and Dwarka sub-basins of northwesternSaurashtra peninsula suggesting probable continuity/linkage between southern on land Kutch and, acrossthe Gulf of Kutch to Saurashtra peninunsula. It isproposed that the evolution of Kutch basin, as apericratonic rift basin, is essentially controlled by thefour (F1-F4) faults inferred from obvious abruptchanges in layer thickness/ velocity along the seismicrefraction profiles.

Key Words: Marginal Rift, Mesozoic sediments,Low Velocity Layer (LVL), Wide Angle Reflection,Skip phenomenon.

S13_I2

Integration of geophysical data for explorationof hydrocarbons - GIS application

T. Harinarayana, C. Manoj and R.S. Sastry(National Geophysical Research Institute, UppalRoad, Hyderabad- 500 007, India)

Geographical Information System (GIS) is aneffective tool in integrating geo-scientific data sets.A pilot project was taken up to integrate the differentgeophysical data generated for Hydrocarbonexploration over Kutch region, India. A base-mapwas prepared from geographical information

S13: Exploration for Oil and Crustal StructureConvener: S.K.Biswas

THEMEMost of the oil provinces are in the areas of complex geological structure and tectonicallyactive regions with repeated earthquakes such as, Northeastern India – Upper Assam,Arunachal, Tripura, & Andaman arc; Northwestern India & Pakistan – Rajasthan, Sind, Punjab & Baluchistan; Western and Central India – Kutch, Cambay & Narmada whichare the active area for SCR earthquakes. Detailed structural studies carried out for oilexploration provide new data and perspective in the thermo-tectonic aspect of theseearthquake prone areas. This may provide new insight in the crustal structure and tectonichistory and help understanding the neotectonic activity and the ongoing seismicity. Withthis in view, papers are invited on structure and tectonics and tectono-sedimentary evolutionof the petroliferous basins in the regions mentioned above, for presentation and discussionin this session.

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obtained from various sources as well as includingthe surface topography. Tectonic map available forthe region was digitized on a regional scale. Thefollowing geophysical datasets obtained over Kutchregion were incorporated into the GIS data base. 1)magnetotelluric (point) 2) residual gravity anomaly(point) 3) aeromagnetic (image). Magnetotelluricdata sets contain the station location, the geo-electricmodel for the site as well as a directional parametercalled induction vector. The depths to various horizonswere smoothed by Kriging and thickness maps ofvarious geological units of the region such as Basalt,Sediment and basement depth were obtained. Agreat deal of new insights into the results of MT ispossible, when a joint analysis of differentgeophysical data sets is carried out. Gravityinformation, overlaid on MT results clearly showthe uplifted basement in central Kutch. To delineatefurther anomalous regions, aeromagnetic mapobtained over Kutch also was overlaid on the othergeophysical data sets. MT induction vectors pointsto conductive regions within Earth. Induction vectorsoverlaid over gravity and magnetic anomalies yieldedinteresting results and gave new information on thesubsurface geology and tectonics of the region. Inter-relationship of these geophysical data obtained byraster calculations, the sub-surface structureparameters and their implication on the hydrocarbonpotential bearing sediments are discussed.

S13_I3

Impact of tectonics, sedimentation processesand evolving trap styles in Andaman island arc.

Sandip K Roy (Department of Earth Sciences,IIT, Bombay. Email: [email protected])

Following the breakup of Gondwanaland, the northwardflight of the Indian plate, its anticlockwise rotation ,impingement beneath the Eurasian plate and incipientsedimentation of oceanic crust derived sedimentsinitiated development of Andaman island arc.

Upper Cretaceous to recent marine sedimentationimpacted by five major benchmarks in associatedprocesses of plate convergence evolved theAndaman island arc as we see today.

The first benchmark is the Oblique subduction ofthe Indian plate beneath the Eurasian plate in LateCretaceous and scrapping of oceanic crust in earlysedimentation processes in Upper Cretaceous-Early

Paleogene time and acidic volcanism at the upperpart of Eocene time. Late Cretaceous sedimentationis marked by Radiolarian cherts, Jaspers, globigerinidlimestones involving deep water sedimentation.Exotic trap derived poorly sorted coarse clasticswith abundant clasts of acidic igneous rock fragments,mudstones and subordinate coal, attributed to debrisflows with and Carbonaceous pyritic shale definesthe Eocene sedimentation .

In Late Oligocene, Change in plate movementdirection along with hiatus , renewed accelerationin subduction , flysch deposition and upliftment ofthe Andaman islands comprised the late palaeogenedevelopment in basin evolution is the nextbenchmark. The flysch is a sand rich system withthin sand shale intercalations intervening thick clastand concretion filled coarse to fine, amalgamatedsandstone beds , noted particularly in the forearcand the subduction zones. N-S trending dextralwrenches, parallel to the plate boundary played asignificant role in shift of arc positions. Theimplications are the role of these dextral shears inshifting coarse sediments to far off positions fromthe provenance during the Paleogene time..

Early Miocene compression in subduction zone andforearc, extensional tectonics in backarc reflectedby pull apart basin formation and active acidicepisodic volcanism from the volcanic arc markedthe third stage in evolution of the island arc. It is aCarbonate rich section with foraminiferal limestonesand finer clastics . NW-SE and NE-SW conjugateshears , very active in Neogene times acted astriggers in generation of structures in Subductionzone-forearc regime. NE-SW pull apart systems inthe back arc due to extension along with rise ofvolcanic arc expressions and sea rises dominatedthe Neogene growth in back arc and volcanic arc.

Renewed Mid Miocene compression near plateboundary, outgrowth of accretionary prism withcontribution of Bengal fan, active conjugate wrenchsystem oblique to Andaman trench and carbonatesedimentation overprinted the arc in the next stageof evolution..

Late Miocene to recent time witnessed true seafloor spreading in the backarc., pyroclastic flows inRitchies Archipelago, emergence of volcanic searises –Alcock and Sewell, and emergence of Ritchies


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Archipelago and some islands in Nicobar withdominant Carbonate sedimentation imprinted thelatest bench mark in evolution. The NW-SEwrenches were active in creation of tight anticlinesin the forearc.

Each tectonic element in the arc system defined itsown trap style .

Piggyback basins and folded accretionary thrustpackets with associated sedimentation affected bygravity flows and turbidity currents , axial turbiditesalong the trench zone, and accretion of sediments inthe accretionary prism. While accretionary thrustpackets symbolized the Cretaceous section in aposition of present day forearc , successively thethrust packets encompassed younger sedimentarypackages from east to west implying a migratorytype of arc trench system shifting westwards.

The forearc is marked by large tight enechelon anticlines,thrust related structures, pinchouts and wedgeoutsagainst the volcanic arc carbonates in Neogene time.BSR,S indicating gas hydrates along with bright spots,flat spots and gas chimneys of seismic controls arealso conspicuous in the Neogene section.

In Neogene, the intra volcanic basins along withstructures associated with pull apart basin formationin the backarc define the structural features awayfrom the Andaman trench in Lower Miocene time.

Fault closures on the flanks of pull apart basins (half grabens) in Oligocene, fluvial channels (Oligocene) , carbonate buildup on highs in earlyMiocene and Pre rift structural traps in the volcanicarc and the backarc..

In the entire evolutionary process, some fundamentalquestions still remain to be defined, like the provenanceof deep marine debris flow affected early paleogenesedimentation, flysch deposition in Oligocene and deepwater carbonate deposition in Neogene, role of dextralN-S strike slip faults in sedimentation with depo centreshifts, pulses of volcanism linked to the entireevolutionary process and lack of seismic imaging inpaleogene and older sections.

Linkage of overriding controls of tectonics tosedimentation is likely to result in better understandingof temporal and spatial facies distribution in relationto trap presence and style in the Island arc.

S13_C1

Geophysical Investigations of the Gulf ofKachchh, Northwest India.

D. Gopala Rao and N. Mahendar (GeologyDepartment, Osmania University, Hyderabad, India.)

The gulf of Kachchh of the northwest India is thelongest east-west trending gulf along the Indian coasts.The tide dominated (5 to 6 m high) gulf is ~75 kmwide and ~125 km long separating the Kutchsedimentary onshore basin from the Saurashtrapeninsula in the south. The Kutch main land basincrust consists of thin Tertiary sediments (includingcoastal alluvium), thick Deccan volcanic rocks andMesozoic sediments overlying the Precambrian crust.The rifted and half graben basin structure is knownextending offshore especially with increase in thicknessof sedimentary sequences. Our recent studies haverevealed that the gulf morphology is dominated bythick alluvial mud-flats of the northern coast exceptingrocky promontories of the northwest coast and coralsrocks (live and relict) of the southwest coast. In viewof the hydrocarbon prospectus of the Mesozoicsediments of the Kutch sedimentary basin and itsoffshore extents, several geophysical investigationsincludes high resolution seismic reflection, single andmulti-channel deep seismic reflection and refraction(Ocean Bottom Seismometer), magneto-telluric,satellite derived free-air gravity, magnetic andbathymetry investigations have been undertaken. Thehigh resolution seismic reflection studies had revealedupper Quaternary sediments seismic sequences ofthe limestone and coral sands and relict coral remnantsand their deposition pattern affected by the sea levelchange of the last 100 Kyrs and neo-tectonics.

The 2-D crust model studies of the gravity andmagnetic anomalies lead to infer presence of 1 to 2km thick volcanic at 0.8 to 1.0 km depth overlyingthe thick low density Mesozoic sediments. It is worthintegration of the results of the deep-seismicreflection and refraction, magneto-telluric, gravityand magnetic anomalies and to shed light further onthe basin crust structure especially thicknesses ofthe volcanic and Mesozoic rocks overlying thePrecambrian granitic crust and their geophysicalcharacters. It shall enable more details of structuralelements affecting the rifted-half graben extent andits termination i.e. whether the rift graben abutsagainst major fault (east-west trending NorthKathiawar Fault)? and the offshore extents of the

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onshore near north-south extending Median High.Plus nature of the faults, basin configuration andtectonics shall help in constraining gulf origin andit’s possible relation to the separation of India fromeastern Gondwana Land during late Cretaceous.

S13_C2

2D-Geoelectric Subsurface structure in thesurroundings of the Epicenter Zone of 2001,Bhuj Earthquake Using MagnetotelluricStudies.

Kapil Mohan1, R. S. Sastry2, T. Harinarayana3

and B.K. Rastogi1 ( 1Institute of SeismologicalResearch, Raisan, Gandhinagar-382009, Gujarat,India., 2Sreemitra cute, Nagarjuna Nagar, Tarnaka,Secundrabad-500017, India., 3National GeophysicalResearch institute, Hyderabad 500007, India.)

Hundreds of aftershocks having magnitude Me”3of 2001 Bhuj earthquake of Mw7.7 have beenrecorded by various agencies like NationalGeophysical Research institute (NGRI) and Instituteof Seismological Research (ISR). Until 2006, theseismicity was very high and the earthquakes ofMw>5 were recorded in the epicenter region. After2006, aftershocks of Bhuj earthquake and seismicactivity are concentrating in the eastern part of theepicentral zone along Samkhiali basin and Wagadarea. To decipher the nature of the faults in this area,two Magnetotelluric (MT) profiles each of length15km have been acquired with an inter station spacingof 1 to 3 km. The profiles have been taken about25km west and east to the epicenter of 2001 Bhujearthquake (23.412oN, 70.232oE) in N-S to NE-SWdirection. From the 1D Bostick analysis of theeastern profile of 11 MT stations, the sedimentarythickness is found to be varying from 1.5 km to 2.3km whereas along the western profile of 8MTstations, the sedimentary thickness is found to bevarying from 400 m to 1.7 km. The 2D inversionanalysis of MT data of the eastern profile showstwo distinctive resistive blocks corresponding toWagad uplift in the north and the Kachchh Mainlandin the south. The KMF is seen west of Bhachau.Further east the geologists believe its extensionbeneath the soil. In this study, the assumed easternextension of KMF is not found. However, a hiddenfault is found 4 km north to the assumed extensionof KMF. At same location in the western profileindications of the fault are also seen which supportsthis result. The possibility of further extension of

South Wagad Fault in the west is also seen along thewestern profile at 14km north of KMF by virtue ofbasement variation of half kilometer.

S13_P1

Passive Seismic Imaging of PetroleumReservoir

Mr. Sunjay (Ph. D. Research Scholar, Departmentof Geophysics, BHU, Varanasi-221005, India)

Low-Frequency seismic waves give geophysicistsa new seismic imaging technique to monitor sweetspots, wealth and health of reservoir. Wavelettransform, known as a mathematical microscope, hasscope to copeup with non stationary signal to delvedeep into geophysical seismic signal processing andinterpretation for hydrocarbon exploration andproduction. Hydrocarbon reservoirs can be the originof a continuous source of low-frequency seismicwaves. These phenomena are sometimes called“hydrocarbon microtremors”. Low frequency (LF)passive seismic is a breakthrough DirectHydrocarbon Indicator (DHI) technology foridentifying and delineating oil and gas reservoirs byanalyzing the spectral attributes of naturallyoccurring, low frequency seismic wavefields. Onesuch technology is low-frequency (LF) passiveseismic technology, which is helping to improve thevalue of conventional seismic data by overlayingstructural interpretations with reservoir information.The existence of coherent patterns relating to oil andgas reservoirs in the low frequency domain has beenestablished in many parts of the world. Twomechanisms that can generate (DHI) in thebackground spectrum are of special interest: resonantamplification and resonant scattering. Resonantamplification effects of ambient seismic waves arelikely candidates for hydrocarbon micro-scale tremorsignals. Resonant amplification effects behave likea secondary source within the reservoir. Resonantscattering occurs on a macro-scale, wherecharacteristic maxima are generated by reflections,both between the reservoir and the surface andwithin the reservoir, caused by complex impedancecontrast due to the reservoir. A wavelet transform isemployed for the joint time frequency analysis ofseismic data. The wavelet transform properties suchas localization, which is essential for the analysis oftransient signals, provide a filter to extractcharacteristics of interest such as energy andpredominant time scales. The orthonormal


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decomposition of the signal energy estimated by thewavelet variance into the retained scales provides auseful means of describing the change in the signalmagnitude associated with the triggering events. Thistype of analysis discriminates between signal phasearrival and spurious signal triggering by the differentmagnitude of local relative energy, which is muchsmaller in the latter case.

S13_P2

Identification of Shallow Geological features inthe Wagad area (Kachchh) using 2D ElectricalSurvey

Kapil Mohan, Girish Patel, Gagan Bhatia,Sunita Devi and B.K. Rastogi (Institute ofSeismological Research, Raisan, Gandhinagar-382009, Gujarat (India))

The Wagad area is very close to the epicenter of2001 Bhuj earthquake. Large number of aftershockswas recorded in the area. Since 2005, the seismicityis shifted to wagad area towards east (ISR annualreport, 2009-10). The South Wagad Fault (SWF) isthe Major Fault in this region. A topographicalvariations of almost 10m in the N-S direction is foundfrom the SRTM (Shuttle Radar Topography Mission)data in the area at Mae dome near Vamka village(23.43oN, 70.39oE, 17km east of the epicenter of2001 Bhuj mainshock (2001 Bhuj Eq.)) and Shivlakhavillage (23.40oN, 70.58oE, 36km east of 2001 BhujEq.). Hence SWF is inferred to be passing in thenear vicinity. However, for the purpose of decidingthe most preferred site of trenching forpaleoseismological study, the exact location of thefault surface has to be found. Therefore, fourelectrical profiles having length of 150 to 220 m havebeen acquired along N-S direction using Syscal Pro(switch 72) instrument to locate the exact positionof the SWF in the region. Profile-I at Vamka village(Mae dome), Profile-II at Halra village (23.40oN,70.46oE, 23km east of 2001 Bhuj Eq., Profile-III atAdhoi village (23.40oN, 70.48oE, 25.5km east of 2001Bhuj Eq. and Profile-IV at Shivlakha village

The resistivity data has been inverted using Res2dinvprogram by least square inversion technique showstwo conductive fracture zones in the Profile-I at 78mand 110m south of the starting point of the profile.The first conductive fracture zone is identified asthe boundary of the Mesozoic and Tertiary rocks.

The second conductive zone is dipping steeplytowards south and is also seen in profile IV and maycorrespond to South Wagad Fault.

S13_P3

2D electrical imaging survey to identify theshallow subsurface layer in the GujaratInternational Finance- Tech (GIFT) City areaof Gandhinagar

Kapil Mohan, Gagan Bhatia, Girish Patel andB.K. Rastogi (Institute of Seismological Research,Raisan, Gandhinagar-382009, Gujarat (India)

The GIFT city is planned near the capital city,Gandhinagar, on the left bank of the River Sabarmatiacross Intitute of seismological Research (ISR), ata distance of around 12 km from Ahmedabad and 8km from Gandhinagar. The 500 acre city willaccommodate a resident population of 50 thousandand a floating population of 5.5 lakhs and act as acentral business district. Looking the economicimportance of the area, the seismic hazardassessment of this region has been assigned toInstitute of Seismological Research by Gujarat StateGovernment. The shallow subsurface geologicallayers play a vital role in the estimation of seismichazard in an area. Therefore 2D resistivity survey(shallow) has been conducted using Syscal-Pro(Switch72) instrument at 23o 09’ 11’’N 72o40’59.6’’E in the area to identify the subsurface shallowlayers. The profile was in N 109o E direction with alength of 497m and with initial electrode spacing of7m.

The resistivity data has been acquired usingSchlumberger and Wenner electrode configurations.The ‘Electre II’ software has been used to createthe electrode sequence and ‘Prosys II’ softwarefor data downloading and processing. The data hasbeen finally inverted through RES2DINV softwareprovided by IRIS. The least square Inversiontechnique has been used to invert the resistivity data.The 2D shallow resistivity pseudo sections thusprepared using both electrode configurations depictresistivity contrast (layers) at a depth of 6.5 and12m, 15m and 35m and 45m. The profile taken fromE to W, shows higher values towards west. Themajor layers are found at 17 and 36m. Thisinformation is used for identification of water tableand soil strength.

10122 - 24 January, 2011


S14: Ground Response Studies for Nuclear Power PlantsConvener : A.G. Chhatre

THEMENuclear Power Plants are designed for Site Specific Earthquake Ground Motion (SSGM).In a nuclear power plant, not only the civil structures but mechanical, electrical, controland instrumentation equipment for safety systems and safety support systems are designedfor Safe Shutdown Earthquake (SSE). The work involves• carrying out geological field check and seismological studies to arrive at the active

faults within an area of 300 Km radius around the plant site,• to arrive at the maximum magnitude earthquake potential of these active faults• to arrive at Site Specific Earthquake Ground Motion (SSGM)Subsequent to that the civil structures and also the mechanical equipment viz. Pumps, Valves,Heat Exchangers, Tanks, Vessels, Piping System, Ducting; Electrical Equipment viz.transformers, diesel generators, cable trays, low voltage & medium voltage switch gears,battery chargers, electrical panels, battery banks and delicate instruments viz., relay,contactors, push buttons, thermowells, pressure gauges, switches are seismically qualifiedby a combination of analysis and shake table tests to demonstrate structural integrity,pressure boundary integrity & functional performance of active components/devices.Huge amount of technical data has been collected all over the world regarding good andpoor performance of Civil structures, Mechanical Electrical and Instrumentation & ControlSystems which have witnessed large number of earthquakes close to the conventionalindustries and Nuclear Power Plants viz., Koyna (1967) & Bhuj (2001) in India whichaffected petrochemical, thermal & hydro power plants, cement & general industry, Kobe(1995) in Japan which affected generally industries, Niigataken Chuetsu–Oki (2007) inJapan which affected Kashivazaki-Kariwa Nuclear Power Plants, Noto Hantou (2007) inJapan which affected Shika Nuclear Power Plant, Chi-Chi (1999) in Taiwan which affectedgeneral industries, San Fernando (1971) earthquake in USA which affected El CentroSteam Plant, Coalinga (1983) earthquake in USA which affected Pleasant Valley PumpingPlant and oil field facilities, Imperial Valley (1979) earthquake in USA which affectedSylmar Converter Station and the Rinaldi Receiving Station etc.

There is a technical session on the topic of ground motion studies for structures, systemsand equipment of Nuclear Power Plants and also on the earthquake resistance design ofIndustrial structures, residential buildings, and bridges. Institutes, Research laboratories& Consultants are involved in the activities of seismic design of residential buildings to agreat extent and also in the design of bridges, industrial structures and Nuclear PowerPlants across the country.Papers are invited in this special session of ground response studies for structures, systemsand equipment of Nuclear Power Plants, Industrial & residential civil structures and Bridges.The topics can be on• Attenuation correlations for active and stable continental region• Geological and seismological studies,• Earthquake ground motion by deterministic and probabilistic method,• Design of structures systems and equipment for Nuclear Power Plants• Structural design of Industrial and residential civil structures, bridges• Performance of the above structures, systems and equipment during the earthquake

Geological studies around nuclear power plants to arrive at the earthquake ground motionfor design of civil, mechanical, electrical and instrumentation of control systems.


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S14_I1

Near-Field ground motion simulation for the26th January 2001 Gujarat earthquake

STG Raghukanth and B. Bhanu Teja (Dept. ofCivil Engineering, IIT Madras-600036, Email:[email protected])

The 26th January 2001 Gujarat earthquakes regardedas one of the devastating event in India provides anopportunity to understand the ground motion in SCR.This earthquake demonstrated the vulnerability ofIndian habitat with rehabilitation and reconstructioncosts at $2.3 billion. The loss of life and damageduring for this event is mainly attributed to thecollapse of built infrastructure in this region. IndianMeteorology Department reported the epicenter ofthis quake at 23.410N, 70.180E. This earthquake alsotriggered wide-spread liquefaction and grounddeformation in the epicentral region. The Gujaratevent generated a lot of interest among seismologistsand engineers because of similar SCR worldwideand also increased the awareness towardsearthquake disaster mitigation in India. Unfortunatelyno strong motion records are available for this eventin the epicentral region. The only way to quantifythe ground motion during this earthquake is throughanalytical approaches. Since the Gujarat earthquakeproduced many ground motion records at teleseismicdistances, finite fault-slip models determined fromthese data are available. From such models, sourceparameters such as location of the epicentre,orientation of the fault plane, rupture dimensions, andslip distribution are known. With this limitedinformation, one can use analytical approaches toestimate ground motion in the epicentral region. Thesoftware package, SPECFEM3D_GLOBE whichis a collection of Fortran subroutines for modelingthe global seismic wave propagation is used tocompute the displacement time histories in theepicentral region. This package has beenimplemented on HP Proliant DL160 G5 serversknown as Vega supercluster available at IIT Madras.The effect of self-gravitation, lateral variations inmaterial properties, ellipticity, topography andbathymetry, the oceans, rotation have beenincorporated in simulating ground motion. The Earthis modelled with 553.4 million grid points.Displacement time histories are simulated at variousstations in the epicentral region. A contour map of

permanent ground displacements in the near sourceregion is provided. The obtained results are validatedto the extent possible by comparing them withrecorded peak ground velocity data and fieldobservations.

S14_I2

Displacement-based Design of Structures: aconsistent framework of limiting-strain baseddesign method

C. V. R. Murty(Department of Civil Engineering, Indian Instituteof Technology Madras,Chennai 600036)

Earthquakes impose displacements at the base ofstructures. This dynamically changing ground-displacement under structures subject to earthquakeshaking then results in imposed relative-deformationsat upper elevations of structures, and therebyrelative-deformations at ends of individual membersof structures. Under strong shaking, the philosophyof earthquake-resistant design expects damage instructural components. The performance of eachmember can be assessed by its capability to withstandthis imposed relative displacement. The currentdesign methods in India for individual structuralmembers are of two types, namely (a) strength-based method (e.g., Limit State Method as statedin IS800-2007), and (b) partially force-based andpartially deformation-based method (e.g., LimitState Method as stated in IS456-2000 and IS13920-2003). These methods cannot help estimate thedeformation capacity of a structure; they can neitherhelp estimate the deformation demand on thestructure under specified ground deformation. Thisis because (a) the Indian steel code (IS800-2007)specifies only design limit states of strength for allload actions corresponding to yield and rupturestrengths; design limit states are not specified ofstrains; and (b) the Indian concrete code (IS456-2000) specifies design limit states only of axial andbending strains; for shearing and torsional actions,only design limit states of strength are specified butnot the design limit states of strains. Thus, acomplete description of the limiting strains is notavailable for all load actions, namely extensional-compressional, bending, shearing and twisting actions,to estimate of deformation capacity of both new andexisting structures.

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The paper proposes a framework for inelastic designof concrete and steel structures (in line with theIndian design codes), which will help in understandingthe level of deformation actions at which designstrength limits are reached, the level of damagesustained by structures when subject to seismicshaking, and the residual-deformation capacity thatcan be relied upon in resisting future ground shaking.The framework will present a description of limitingstrain states for all load actions; it will caution onpossible interactions between these strain effects.The emergence of such a method is expected tolead to a greater reliability of earthquake-resistantdesign of structures.

S14_I3

Seismic Design of Bridges for DisplacementLoading

Rupen Goswami (Department of CivilEngineering,Indian Institute of Technology Madras)

Traditional earthquake-resistant design of bridges isbased on equivalent lateral forces estimated as perthe codes of practice. There is no provision limitingthe lateral deflection of bridges. Further, there is noexplicit requirement on the minimum ductility ofbridges. All inelasticity, and hence ductility, isexpected to be through the nonlinear actionsrestricted to the substructures. In the currentpractice, the level of ductility embedded in thesubstructures is not clearly quantified at the time ofdesign. Prescriptive ductile detailing requirements forbuilding columns are being extrapolated for bridgepiers also. Explicit experimental studies are notavailable within India on the inherent ductility ofbridge piers designed as per Indian codes. Theexpected relative displacement demand on bridgepiers is not quantified in the codes of practice fordifferent seismic zones. With both the demand andthe supply not estimated, actual behaviour of bridgesis unknown, especially under strong seismic shaking.

In addition, the problem is pronounced in the near-field regions (of proximity to seismic faults), wherethe expected displacement under bridges can belarge. Ground displacement observed is significantlydifferent under near-fault motion, and can imposeon bridges, large residual or permanent displacement(as in fault normal condition) or large instantaneousor peak ground displacement (as in fault parallelcondition). These instantaneous or permanent

displacements are to be accommodated in the bridgeand its substructure, which must have adequatelateral displacement capacity.

This paper highlights issues related to ways ofassessing lateral displacement capacity of reinforcedconcrete bridge piers, and improving the samethrough choice of section and detailing.

S14_I4

Earthquake Experience based performance ofcivil structures, piping systems, cable trays,ducting and mechanical, electrical,instrumentation & control equipment fromindustries in India

Faisal Dastageer, Anshuman Singh, RahulMittal, Santosh Khandwe, B. Santosh, U.P.Singh, S.D. Bhawsar, R.N. Bhawal, S.M.Ingole, and A.G. Chhatre (Nuclear PowerCorporation of India Limited, Mumbai) andRajesh Mishra (Bhabha Atomic ResearchCenter, Mumbai)

Nuclear Power plants in India have been designedfor earthquake resistance by the methods of analysis& testing. Many of the electrical & instrumentationequipment have been tested on shake tables availablein India. The performance of the civil structures,piping systems, cable trays, ducting and mechanical,electrical, instrumentation & control equipment inindustries around Koyna (1967, 6.5 M), Bhuj (2001,7.6 M) & Muzaffarabad (2005, 7.6 M) which havewitnessed the earthquake is also available.

Contrary to the common perception that Koyna, Bhujand Muzaffarabad earthquakes were a completedisaster, the data collected on equipment performancefrom the industries around the area was that theequipment and piping failure due to inertial load wererather nil and wherever the failures were there, theywere due to total collapse of the civil structure in whichthey were installed or falling of brick wall on to theequipment or piping or failure of equipment due toimproper or no anchorage of the equipment or due toseismic anchor movement. Apart from the failures oftransformers on wheels, battery banks on woodenstillage, false ceiling, lighting fixtures and brick wallsthe performance of other equipment was good (tanks,pumps, valves, compressors, DGs, fans and blowers,chillers, HVAC ducts, cranes, transformers,switchgears, MCCs, battery chargers and inverters,battery banks, distribution panels, MG sets, cable trays,


104 22 - 24 January, 2011

false ceiling, glass partition, lighting fixtures, brick walls,piping system, instrumentation and control panels,instrumentation devices like relays, temperature andpressure sensors, switches, meters etc )

Indian experience on equipment which havewitnessed earthquake is from the general industry,although not from the Nuclear Power Plants, viz.thermal & hydro power plants, chemical & fertilizerindustry, cement plants, petrochemical plants,electrical substations etc. and is very similar to theexperience at Kashiwazaki-Kariwa NPP on softrock(Vs30 200m/sec) and Shika NPP on hardrock(Vs30 1500m/sec) in Japan.

Earthquake experience data from USA, Europeancountries, Russia, Japan etc. as available in the formof Generic Implementation Procedure GIP-DOE,GIP-SQUG, GIP-VVER, FEMA, ASME-QME 1-2000, IEEE-628 etc. as collected by various institutese.g. EPRI, EERI, LLNL from USA have also beenused.

The performance of the equipment during the shaketable tests or during the earthquake forms the database of equipment, which can be used by generalindustry as well as by nuclear industry for their designand forms the part of the experience based data.

S14_I5

Seismic Analysis of a typical Nuclear PowerPlant structure

Apurba Mondal, Indrajit Ray, Raghupati Roy,D.K.Jain1, U.S.P. Verma (Nuclear Power Corpo-ration of India Ltd., Mumbai, India)

The operating experience of Nuclear Power plantswith 220 MWe & 540 MWe PHWRs havedemonstrated that they are safe, reliable and costcompetitive. The next generation Indian 700 MWePHWR has been designed after modifying the basicfeatures of 540 MWe Indian PHWR. From theconceptual stage of 700 MWe PHWR plant layoutas well as structural layout has been developedconsidering the both constructional aspect as wellas improvement in structural performanceparticularly with respect to seismic loading.

The Nuclear Building, which is specially conceivedfor the Indian 700MWe PHWR projects, consists ofreactor building (RB), spent fuel storage bay (SFSB)and the remaining portion housing various reactorauxiliary systems. In order to achieve improved

structural performance and bring overall economyin the structural design and to suit faster constructionconsidering the present day advanced constructionmethodology, a common foundation raft for the reactorbuilding, SFSB, reactor auxiliary building and variousservice areas has been planned. The structuralframing in the Nuclear Building outside RB has beenconnected to the cylindrical outer containmentstructure in order to utilize the structural stiffness ofthe outer containment wall in improving the seismicresponse of the portion of the NB around RB.

Nuclear safety related structures are designed fortwo levels of earthquakes i.e OBE (operating basisearthquake) & SSE (Safe shutdown earthquake).The detailed 3-D integrated finite element model ofthe structural system along with the simplified modelsof the major equipment has been considered. Thesoil-structure interaction analysis is also carried outwith sub-structure approach.

Fluid-structure interaction of pool water is alsoappropriately considered. Detailed methodology hasbeen developed to incorporate the accidental torsionfor structural design purpose.

S14_C1

Design of Distribution Systems, viz., Piping,Cable Trays and Ducting

Faisal Dastageer, Anshuman Singh, RahulMittal, Santosh Khandwe, B. Santosh, U.P.Singh, S.M. Ingole, R.N. Bhawal, S.D.Bhawsar* and A.G. Chhatre (NPCIL, Mumbai)

Lots of efforts are put up in seismic qualification ofpiping system by performing time history analysis,response spectrum analysis or multi support excitationanalysis to find out the inertial forces and the resultantstresses in the piping component.

As done in other parts of the world in the past, theNuclear Power Plants in India on hard rock havebeen designed for ground motion of soft rock,since not many records were available from the hardrock sites. The supports for the piping, cable traysand ducting in conventional industries in general wereof rod hanger type. The piping and cable trays withrod hangers have frequency less than 1 Hz and shouldexperience an acceleration of about 0.03g, however,the soft rock spectrum used for the designnecessitated the piping and cable trays to meet anacceleration of 0.2g instead of 0.03g. As the rod

10522 - 24 January, 2011


hangers could not meet the qualification requirementfor these accelerations, the supports were changedto angles and channel sections, thereby increasingtheir stiffness & frequency, resulting in attractingmore acceleration, further, requiring increase inthe support section size, till the frequency of thesystem goes in the descending part of the responsespectrum. Now, this process of increased supportstiffness is being reverted back to meet the lowacceleration in low frequency region of the hard rockground motion.

Large unrealistic conservative floor response spectraare one of the another reasons for conservative rigidsupports or snubber on piping. The analyticallycalculated floor response spectra for Kashiwazakikariwa(on soft soil) and for Shika (on hard rock )are higher by about 40% on first floor and by about100% on second floor than the recorded values. Theaim of putting the Seismic instruments in a NPPbuildings is to benchmark the analytical calculationsso as to remove the areas of un-conservatism lf any,but the aim is also to remove the areas of too muchconservatism as well. As brought out above, basedon the feed back from the experienced based data,there is a need to re think and correct ourselves inour design methodologies.

In case of piping, it observed that there are no failuresobserved due to inertial loads, rather the failures aredue to Seismic anchor movement or due to rigidsmaller piping connected to bigger equipment. Thereis a possibility of failure of piping due to inertial loadwhich may be due to reduction in load carryingcapacity of the piping due to thickness reductionbecause of corrosion which can be tackled by regularin-service-inspection or by replacement, if thethickness goes below allowable value. As observedin Indian experience from general industry and alsofrom Kashiwazaki Kariwa NPP Shika NPP in Japan,piping have survived with both rigid supports as wellas with flexible rod support. So it is better to have aflexible piping with rod hangers rather than rigidpiping with closed spaced supports with U clamps.Flexible piping can withstand SAM with comfortablemargin and will have low thermal stresses.

In view of number of similar observations, there is aneed to understand, as to, whether there is a need ofconducting the time consuming response spectrumanalysis of piping system to arrive at the seismic

inertial responses which anyway have not causedany failure. There is need of conducting a simplifiedseismic design of piping system and the supports bytables and charts aided by equivalent static analysis.

Similar is the case of cable tray and ducting, in orderto not to attract higher accelerations by going indescending part of the response spectrum where theacceleration are lower for the soft soil spectra, thesupporting system have been made rigid to increaseits stiffnesses. However, based on the experienceof the real earthquakes, it is seen that if one makethe system flexible, it will result in attracting lesserearthquake accelerations and of light weight. Bymaking the supports rigid, it does not add any safetybut makes the whole system uneconomical, so, thereis a need to look into the supporting of cable traysand ducts.

S14_C2

Earthquake Ground Motion Generation forNuclear Power Plant

Faisal Dastageer, Anshuman Singh, RahulMittal, Santosh Khandwe, B. Santosh, U.P.Singh, S.M. Ingole, R.N. Bhawal, S.D.Bhawsar* and A.G. Chhatre (NPCIL, Mumbai)

The Nuclear Power Plant (NPP) is designed for twolevels of earthquake viz., Operating BasisEarthquake (OBE) (S1) and Safe ShutdownEarthquake (SSE) (S2). The OBE (S1) level groundmotion corresponds to the maximum level of groundmotion, which can reasonably be experienced at thesite once during the operating life of nuclear powerplant with a return period of 100 years. Whereas,the SSE (S2) level ground motion corresponds tothe maximum earthquake potential of the (site) regionwith a return period of 10000 years. SSE representsthe maximum level of ground motion to be used fordesign of safety related structures, systems andequipment (SS&E) of NPP. For these two levelsof earthquake i.e. OBE (S1) & SSE (S2), it isrequired to specify the Site Specific Ground Motion(SSGM) from which the Design Basis GroundMotions (DBGM) is arrived at.

A study of regional geology and seismo tectonicfeatures in the region of 300 km radius from site arerequired to be conducted to delineate the faults/lineaments based on the landsat imageries, as givenin Seismotectonic Atlas of India and its environs,


106 22 - 24 January, 2011

gravity anomaly map and also based on MicroEarthquake (MEQ) and Earthquake data (historicalas well as recorded) in the region. The field checkstudy is carried out in three ranges viz., Local (5Km), Intermediate range (50 km) and Regional (300km). Based on the field check study, the lineamentsare given a status of capable fault and a maximumearthquake potential (in terms of magnitude) anddepth of focus are assigned.

For determining the ground motion, a SSE (S2) levelof earthquake is required to be determined in termsof Maximum earthquake potential (in terms ofMagnitude, Depth of focus, and Epicentral distance(Closest distance of the active fault).

The ground motion is determined deterministically bythree methods viz., first from the recorded time historiesfrom the site or from the sites having similar geologicaland seismological features, secondly in the areas withlow seismicity were recorded time histories are notavailable one can generate synthetic ground motionfor the ground motion parameters viz. stress drop,geometric attenuation, inelastic attenuation and kappaand site amplification, thirdly in the areas of lowseismicity one can also use the attenuation correlationdeveloped for the region using the recorded groundmotion or the synthetic ground motion.

In the time history based method whether actualrecorded or synthetic, normalized mean plus onesigma spectral shapes can be determined forcontrolling level of earthquake The aim of generatingthe normalized mean plus one sigma spectra forsuch a range of S2 level of earthquake time historiesis to generate a mean plus one standard deviationspectra i.e. to define Dynamic Amplification Factors(DAF) with 84% non exceedance probability at allthe frequencies and not only the maximum DAF.

The normalized mean plus one sigma spectral shapescan then be anchored to the weighted mean PGAderived using number of correlations suitable for thegeology and tectonics of the region for the controllingearthquakes.

In case of the attenuation correlation based method,the mean plus one sigma spectra is generated usingweightages to the correlation at all the frequenciesincluding the pga for the controlling magnitude &distance level of earthquakes to get the SSGM.

The DBGM is obtained from the SSGM by joiningthe peaks of the SSGM and smoothening.

The paper brings out the procedure for conductingfield check study, determination of the ground motionby deterministic method and also a case study offield check carried out and generation of groundmotion for KAPP-3,4 Nuclear Power Plant site.

S14_P1

Estimation of Spectral decay parameter Kappa,Seismic Moment, Stress drop, SourceDimension and Seismic Energy for SmallEarthquakes in Kachchh region from StrongMotion

Santosh Kumar1, Dinesh Kumar2,B.K. Rastogi1

(1 Institute of Seismological Research, Gandhinagar.2 Department of Geophysics, KurukshetraUniversity Kurukshetra 136 119 India)

The spectral decay parameter Kappa (k)characterizes the sharp decay at high frequency ofacceleration spectra. This sharp decay of seismicenergy may be attributed to source effect orcombination of near surface attenuation and nearsurface effect. A set of 108 accelerograms from 25earthquakes recorded at 15 sites in Kachchh regionhave been spectrally analyzed to estimate kappa andother source parameters including seismic moment,stress drop and source dimension. The Brune’ssource model has been used for this purpose. Theaccelerograms used here have been recorded in theepicentral distance range of 10-100 km. The kappavalues have been found in the range 0.022 - 0.026.The source radii are found to be between 200m to900m. The stress drop value is 100 bars for most ofthe events. It shows Kachchh to be a the high stressregime. The estimated seismic energy ranges from1.83 × 1010 J to 7.35 × 1012 J. The source parametersestimated here are useful for understanding theearthquake source model of the region. The kappavalues obtained here can be used to simulate strongground motions from moderate to large earthquakesin the region which in turn is useful for the properevaluation of seismic hazard in the region.

S14_P2

Seismotectonic study to characterize theseismic sources in Gulf of Khambhat andprediction of strong ground motion in thesurrounding Saurashtra and Mainland regionsof Gujarat (India)

10722 - 24 January, 2011


Sandeep Kumar Aggarwal(Email: [email protected]),Sumer Chopra, Babita Sharma, B. Sairam,Santosh Kumar, Vishwa Joshi andB.K.Rastogi (Institute of SeismologicalResearch, Gandhinagar-382009)

The widely felt earthquake of Mw3.5 on 02nd May,2008 at 27.6km depth in Gulf of Khambhat near Suratwas recorded at 33 broadband stations of Gujarat.Two aftershocks of Mw 3.2, 2.7 were recorded withinone hour. The seismic data within 80 to 160 km providedan opportunity to study the seismotectonics of theregion by determining Centroid Moment Tensor(CMT) solution and source parameters. The CMTsolution depicts WSW-ENE tectonic trend coincidingwith the trend of Narmada-Tapti rift. The earthquakemay be generated by a localized earthquake sourceon the segmented fault extending in WSW-ENEdirection. The Narmada-Son rift has a capacity toproduce Mw6.5 earthquake. The observed weakmotion velocity data are used to find PGA (peakground acceleration) at eight sites within 80 to 160kmaround the epicenter. The magnitude 3.5 earthquakeis taken as an element earthquake and using this Mw6.5 target earthquake is generated by EGFMtechnique in two step simulation. The calculated PGAin South Gujarat is varying from 50 to 80 gals and inSaurashtra region varying from 60 to 80gals within 80to 160 km. This study represents that the Saurashtraand Mainland regions of Gujarat can expect PGAbetween 50 to 80 gals from an earthquake near Suratin Gulf of Khambhat.

Key wards: Surat, Seismotectonics, Saurashtra, Gulfof Khambhat

S14_P3

Site characterization using Vs30 and siteamplification in Gujarat, India

B. Sairam1 (E-mail: [email protected]),B. K. Rastogi1, Sandeep Aggarwal1, K. S. Roy1

A. G. Chhatre2 and Rajesh Mishra3 (1 Instituteof Seismological Research, Raisan-382009Gandhinagar, 2 NPCIL Mumbai, 3 RARC, Mumbai)

Gujarat has experienced great earthquakes inhistorical past the last being on 26 January 2001 thatstruck Bhuj. The Bhuj earthquake (Mw 7.7) wasone of the most destructive intraplate earthquakesof India, causing catastrophic damage and casualtiesto the state of Gujarat, killing about 15, 000 people,

injuring many more. An intensity of X close to theepicenter has been estimated on a Modified MercalliIntensity (MMI) scale. The Bhuj earthquake causedsevere damage not only in the epicentral region, alsospreading to over 350 km distance like Ahmadabad,Bhuj, Rajkot, Anjar, Gandhidham, Morbi, andSurendranagar. In these cities single to multistorybuildings collapsed. Soil covered areas experiencedhigher damage than hard rock areas. Whole ofGujarat region has the earthquake hazard of differentlevels from moderate to high as zones II - V areassigned to it in the seismic zoning map of India. Inthe Gujarat region an earthquake of magnitude 5 to8 can be expected. Thus, there is a great need forsite characterization and seismic hazard mapping ofthe area. We have measured Vs profiles at 200 sitesin different geological units viz Deccan trap (DT),Tertiary rocks (TR), Cretaceous rocks (CR),Limestone (LS), Jurassic rock (JR), Laterites (LT),Quaternary sediments (QS), including Holocene tidalflats (HTF) and estimated Vs30 of these geologicalunits in the range of 600 – 1000, 430 – 960, 450 –680, 525 – 675, 385 – 510, 400 - 450, 190 – 470 and140 – 180 m/s, respectively. These geological unitsare also classified according to NERHP classificationbased on their Vs30 which are: C-B type: DT andTR; C-type: CR, LS, JR, and LT; D-C type: QS andE type: HTF. Further, site amplification (SA) at 50sites was estimated using earthquake records. TheSA sites were well distributed and covered differentkinds of geological units. The Estimated siteamplifications of NERHP classes viz B, C, D, E arein the range of 0.9 -1.6, 0.6 – 3.3, 2.8 – 4.4 and 5.9– 6.7, respectively. A plot of Vs30 versus siteamplification is showing that the amplificationincreases with decreasing Vs30. From thisobservation it is inferred that Vs30 is a good proxyfor site amplification.

Each geological unit has been classifiedaccording to NEHRP classification based on Vs30.by doing this, we are creating site condition map ofGujarat where each site can be classified by a generalgeological category. then, these general geologicalunits can be used to transfer Vs estimates of thegeological units to SMA/SRR/industrial/nuclearpower plant sites located on them these velocityestimates are used develop Next GenerationAttenuation (NGA) relation applicable for differentsoil categories of Gujarat and also for generation ofsynthetic seismograms and response spectra.


108 22 - 24 January, 2011

S15_C1

Hydrodynamic Modelling of 2004 Indonesianand 1945 Macran Tsunamis

R. Rajaraman (1Materials Science Group E-mail:[email protected]); S. Joseph Winston(Metallurgy & Materials Group, Indira GandhiCentre for Atomic Research, Kalpakkam – 603102, TN, INDIA.)

Hydrodynamic modelling of tsunamis has progressedextensively in recent times, thrust by the vast datarecorded for the December 2004 Indonesian tsunamiwhich swept across countries bordering IndianOcean. This significantly enhances the verificationand benchmarking the numerical models. Primaryobjective of these modelling studies is to improve onthe advance warning systems towards the disastermitigation efforts. Another crucial role of suchtsunami modelling is to analyse impact of worst casescenarios for the specific coastal regions having thickpopulation or infrastructures such as power plants.As part of the initiative by Department of Atomicenergy, India to benchmark tsunami impact for Indiancoasts, numerical modelling of 2004 Indonesian and1945 Macran tsunamis has been carried out toestimate runup and inundation at select locations.

Global propagation has been modelled using finitedifference code, originally developed by C. L. Maderand implemented as part of MIRONE suit, withGEBCO bathymetry data. Local inundation

S15: Tsunami ModellingConvener: V.P.Dimri

THEMEEast coast of India is affected by tsunami generated along Andaman-Sumatra subductionzone and west coast from Makran subduction zone. Numerical modeling to determine thetsunami propagation, potential run-ups and inundation from tsunamigenic sources isrecognized as useful and important tool, since data from past tsunami are usuallyinsufficient to plan future disaster mitigation and management planes. Models can beinitialized with potential worst case scenarios for the tsunami sources or for the wavesjust offshore to determine corresponding impact on nearby coast. Models can be initializedwith smaller sources to understand the severity of the hazard for the less extreme butmore frequent events and also far taking into account the shape of the coast line andshelf. Paleotsunami study is important to decipher pre-historic tsunamis. All this informationthen forms the basis for creating tsunami evacuation maps and procedures. Papers areinvited on these topics regarding tsunami studies.

computation has been carried out for select locationsusing finite volume code ANUGA with highresolution bathymetry and land elevation data. Spatio-temporal dependent orthogonal surface momentumand wave height histories derived from globalpropagation model were transferred to finite volumesolver for accurate inundation studies. Owing tointensive computing resource requirements of highresolution inundation modelling, finite volume solverwas run in parallel environment.

Finite volume code has been benchmarked toreproduce one dimensional channel propagationstudies of Kowalik and the 2D tank experiment ofthe Okushiri tsunami. This paper presents the resultsof the simulation of the Dec-2004 IndonesianTsunami with specific emphasis for the eastern sideas well as the 1945 Macran Tsunami for the westernside of India. Inundation profiles and runups arecompared with available field data, highlighting thesatisfactory usability of such modelling for disastermitigation preparedness for the entire Indian coast.

S15_C2

Tsunami Assessment of Indian Nuclear CoastalSites for Sumatra 2004 and Makran 1945Tsunami Events

R. K. Singh (Reactor Safety Division BhabhaAtomic Research Centre, Trombay, Mumbai 400085,India), P Sasidhar (Safety Research Institute,Atomic Energy Regulatory Board, Kalpakkam,Tamilnadu, India)

10922 - 24 January, 2011


The two tsunami events due to Sumatra earthquakewith magnitude 9.3 of December 26, 2004 andMakran earthquake with magnitude 8.1 ofNovember 28, 1945 are of interest for the presentand future prospective nuclear coastal sites of India.The tsunami generated due to Sumatra earthquakeis well studied and reported, however, the Makranevent has associated larger uncertainties due to lackof historical data. The paper describes a rationaltsunami modeling and validation study for the run upand inundation assessment for Indian coastal siteswith due consideration to the source term modelingfor these two potential tsunami sources.

Bhabha Atomic Research Centre, Trombay initiallyundertook computational simulation for all the threephases of tsunami source generation, propagationand run up evaluation for the protection of publiclife, property and various industrial infrastructureslocated on the Indian coastal regions for the NationalTsunami Warning System. Further, studies have alsobeen carried out for the protection of the coastalnuclear facilities. The site selection and design ofIndian nuclear power plants require the evaluationof run up and the tsunami mitigation measures forthe coastal plants. Besides it is also desirable to assessthe early warning system for tsunamigenicearthquakes. The tsunamis originate from submarinefaults, underwater volcanic activities, and sub-aeriallandslides impinging on the sea and submarinelandslides. In case of a submarine earthquake-induced tsunami, the tsunami wave is generatedwithin the ocean due to displacement of the seabed.These studies have been effectively utilized for designand implementation of early warning system forcoastal region of the country in addition to the siteevaluation of Indian nuclear coastal installations. Thetsunami wave modeling using shallow water wavetheory is first presented with in-house finite elementcode Tsunami Solution (TSUSOL) throughnumerical simulation of Sumatra-2004 and Makran-1945 tsunami events. The time signal analysis of thewave time history from TSUSOL code confirms thereflections from Sri Lanka and various other Indianislands. The reflected wave periods from Sri Lankacomputed as 4096 sec, 2560 sec and 1280 seccompare well with the spectral periods of 4380 sec,2580 sec and 1320 sec respectively from the de-tided data of NIO tide gauge records. The tsunami

source modelling with regard to the fault parameters,fault multiple segments and orientations are describedto identify and characterize the tsunamigenicearthquakes in Indian Ocean. The TSUSOL code isshown to have special capability of coupled tsunamiand acoustic wave simulation, which is an importantfeature for the early warning system. Coupledseabed and water column dynamic models areproposed for identifying the tsunamigenicearthquakes with help of tide gauge wave form timesignal analysis and the associated tsunami periodsand wave lengths.

As an inter-code comparison and codebenchmarking exercise, using a refined localbathymetry and land morphology data, detailinundation modelling has been carried out forKalpakkam nuclear site in South India for tsunamievent of Sumatra-2004 with different tsunaminumerical codes through a systematic NationalRound Robin Exercise with participants fromresearch, academic and technical organizations.Detail computational results of inundation reach andwave run up for Kalpakkam site are presented andare shown to have reasonable comparison with thepost tsunami measurements carried out after theSumatra-2004 tsunami event. A sensitivity analysisof the results obtained from the different codes iscarried out with regard to various modelling schemesand assumptions. The influence of bottom frictionand Coriolis forces and issues of coupling of stormsurges with tsunami waves to evolve the design basisfor the coastal nuclear facilities have been addressed.The result of this assessment has been further utilizedfor tsunami hazard evaluation of coastal nuclearplants in India.

For the Makran event, Tarapur site has been chosenfor detail inundation and run-up study. The easternand western halves of Makran subduction zones havedifferent seismic patterns. The regions of westerncoast have very shallow depths and separationbetween the global and global models was arrivedfrom the modelling experience of Sumatra event.This resulted into mminimization of the numericaldispersion and diffusion in the multi-grid models tocapture natural physically consistent amplitudedispersion and phase dispersion for accurateinundation and run-up modeling.


110 22 - 24 January, 2011

Keywords: Tsunami hazard, coastal nuclear sites,inundation height, tsunami modelling, numericalcodes.

S15_C3

Development of Paleo-Tsunami Database andHazard Assessment for Indian Subcontinentfrom A & N Islands

Akhilesh K. Verma and William K. Mohanty(E-mail: [email protected]).(Department of Geology and Geophysics, IndianInstitute of Technology, Kharagpur–721 302, India)

Many destructive tsunamis have occurred in theIndian Ocean and in the Mediterranean Sea althoughthe frequency of occurrence is very less as compareto the Pacific Ocean. In the present study, a paleo-tsunami database has been prepared for Indiansubcontinent from various sources such as NOAA/WDC. The Indian coastal belt has not recorded manytsunamis in the past. Most of the events recordedare true paleo-tsunamis that occurred prior to thehistorical record or have no written observations.The one well documented devastating shallow mega-thrust earthquake-cum tsunami (MW>9) ofDecember 26th, 2004 occurred on the interface ofthe India and Burma plates and was caused by therelease of stresses that develop as the India platesubducts beneath the overriding Burma plate. Almostall the countries situated around the Bay of Bengalwere affected by the tsunami waves during thisdestructive event. The resulting tsunamis from IndianOcean devastated the shores of Indonesia, Sri Lanka,India, Thailand, and other countries, even reachingthe east coast of Africa, 4500 km (2,800 miles) westof the epicenter. The Andaman and Nicobar (A&N)islands in the southeast of mainland India are theIndian land masses closest to the epicenter of the 26December 2004 event. Commenting on the recentearthquake that occurred, the Andaman and NicobarIslands took place in a most seismically active regionin the world and at the plate boundary separatingthe Indian-Australian and East-Asian Plates. Inaddition, we have also carried out the maximummagnitude (mmax) and the b value for this tectonicallyactive region. The mmax is estimated for Andamanand Nicobar region only, the earthquake catalogue

do not include the 26th, 2004 event of momentmagnitude 9.3. The estimated maximum possiblemagnitude (mmax) and b value for the Andaman andNicobar region are 8.2 ± .54 and 1.05 ± .02respectively. The maximum observed magnitude inthis region was 7.7. This preparation of databaseand hazard analysis may efficiently useful to improveour understanding about tsunami sources, even itsmagnitude and frequency.

Keywords: Paleo-tsunami, database, India,Andaman and Nicobar Islands, mmax, b value, Hazardassessment.

S15_C4

Tsunami Effect on Porbandar, Western GujaratCoast.

V. M. Patel2 ( E-mail : [email protected]),H. S. Patel2 (E-mail : [email protected]),A. P. Singh3(E-mail : [email protected])(1Ganpat University, Ganpat Vidyanagar,Mehsana-384002, Gujarat, India.2 Department ofApplied Mechanics, L. D. College of Engg.,Ahmedabad, Gujarat, India. 3 Institute ofSeismological Research, Gandhinagar, Gujarat,India.)

Almost all of the recorded tsunamis along the ArabianPeninsula have occurred on its eastern and southernedge, some, such as the one formed by the 1945Makran earthquake, were extremely destructive. TheIndian Ocean is the most likely source area for futuredestructive tsunamis (Jordan, 2008 & Rastogi, 2006).The most significant tsunamigenic earthquake inrecent times was that of 28 November 194521:56UTC (03:26 IST) with a magnitude of 8.1 (Mw). Inthis paper an attempt is made for a numericalsimulation of the tsunami generation from the MakranSubduction Zone, and its propagation into the ArabianSea and its effect on the Porbandar city of Gujarat,India, through the use of a numerical model. It isobserved from the results that the simulated arrivaltime of tsunami waves at the Porbandar is in goodagreement with the available data sources. In thisstudy more importance has been given to the run upheight of tsunami waves, arrival time and inundationmap. Also effect of different fault parameters onbasic data is also studied.

11122 - 24 January, 2011


Keywords: Earthquake, Tsunami, MakranSubduction Zone (MSZ), Numerical Modeling,Porbandar.

S15-P1

Numerical modeling of Arabian Sea tsunamipropagation and its effect on the Gujarat Coast(India) as well as tsunami directivity fromMakran and Andaman-Sumatra sources

A. P. Singh (E-mail: [email protected]) andB. K. Rastogi (Institute of seismological research(ISR), Raisan, Gandhinagar-382009, Gujarat (India))

Historically, tsunamis are a reality in the Arabian Seaand one of the most deadly tsunami ever in the regionoccurred on 27th November 1945. Seismologists areconcerned about the possibility of the occurrence oftsunami in this region again. Therefore, it is importantto know about the impacts of tsunami wave onGujarat coastline, especially the extent of inundationin coastal towns. Mathematical modeling of tsunamiprovides an effective tool to know about the tsunamipropagation and its impact on land. The shallowwater non-linear mathematical model TSUNAMI-N2 is used for tsunami propagation and inundation.In this model, a set of nonlinear shallow waterequations with bottom friction term are discretizedby the leap-frog finite difference scheme. The modelgenerates the water level displacement in modeldomain at given time intervals for all nested gridsand maximum water level displacement at each gridcell independently of the time when it occurred. Forthe modeling of tsunami, open source bathymetryand topography data (GEBCO) which is availableat 1 minute interval is used. The fault parameters ofthe earthquakes for the generation of tsunami arestrike 2700, fault area (200km length and 100kmwidth), angle of strike, dip and slip (270°, 15° and90°), focal-depth (10 km) and magnitude of 8.0. Forthis study, the initial vertical displacement of the seabottom is calculated with the Mansinha and Smylie

(1971) method. The initial displacement is generatedin the study area with the hypothesis that the seabottom displacement is immediately reflected in asea surface displacement. If the strike is 2500

, thedirectivity is towards India.

The simulation of model results were stored inan animation movie at every minute using MATLABand found that the tsunami wave propagated initiallyvery fast in Arabian Sea and slowed down when itreached shallow sea near Gujarat coast, Gulf ofKachchh and Gulf of Cambay. At the source, itgenerates 6-7 m tsunami at the moment of theearthquake. At Dwarka, positive tsunami wavesarrive within 2 hours and 10 minutes and Mandvi ittakes 3 hours 10 minutes, if the source is easternMakran. If the fault strike is 250°, the travel timereduces. However, if the source is considered alongthe western part of Makran, the travel time increasesby twenty minutes. The tsunami strikes Dwarka,Jakhau and Porbandar with 2.0, 2.5 and 1.5m run-ups, respectively. If the tsunami strikes during hightide, we should expect more serious hazard whichimpacts local coastal communities. The study oftsunami inundation along Gulf region shows that thereis no impact during low water in inner gulf, however,a combined effect of high water and tsunami wavehas a great impact inundating up to 1200 m in Mandviarea.

Directivity of Andaman-Sumatra, 1300 km longsource zone is studied by dividing it into fivesegments. Each segment is assumed to havedifferent fault parameters. The northern threesegments comprising Andaman-Nicobar belt arefound to be contributing to the tsunami affecting eastcoast of India and directivity of the southern twosegments comprising Sumatra is away from India.The combined effect of all the segments is alsoestimated. This estimate gives 7-8 m run up atNagapatanam, the most affected place in Indiaduring December 2004 tsunami..


112 22 - 24 January, 2011

S16-IGCP_Keynote-1

Archaeoseismology and the role of tectonicsin the demise of the Indus Valley Civilization

Pradeep Talwani (Department of Earth andOcean Sciences, University of South CarolinaColumbia, SC, 29208, USA)

The study of how earthquakes affect archaeology,archaeo-seismology, is a nascent forensic sciencewhere in archaeologists are beginning to appreciatethe role of earthquakes in the destruction of structuresand earth scientists are beginning to decipherarchaeological ruins to fill gaps in their knowledgeof prehistoric earthquakes and improve seismichazard assessment in a region. Recent archaeo-seismological studies have shown the role ofearthquakes in the destruction of major structuresand end of many civilizations in the seismically activeregion in and around the Mediterranean Sea. Someof the techniques employed in archaeoseismologyinclude the identification of the affects on structuresof the horizontal and vertical ground movements onwhich they are built, and on the patterns ofdestruction due to shaking.

Several causes have been attributed to the suddenend of the Indus Valley Civilization, ~2500 to 1700years before present. Among these, a cause I willexplore in my talk is the role of tectonics. I will alsoexplore the possibility of conducting archeo-seismological investigations to decipher the ancientearthquakes that leveled Dholavira, the ruins of whichlie on the seismically active Island Belt fault.

S16_IGCP-I1

Major Earthquake Occurrences inArchaeological Strata of Harappan Settlementat Dholavira (Kachchh, Gujarat)

R.S. Bisht (E-mail: [email protected]),Former Joint Director General, ArchaeologicalSurvey of India, 9/19 Rajendra Nagar III,Sahibabad, Ghaziabad, U.P. 201 005

Archaeological excavation at Dholavira, DistrictKachchh, Gujarat, (during 1990-2005) has suggestedthat the Harappan settlement thereat visited by atleast three major seismic episodes of intensemagnitude at different time-periods during the thirdmillennium BCE. Significantly, the first two broughtabout qualitative changes in the planning as well asin cultural form, of course, for good as the state ofeconomy was healthy and growing, while the thirdone dealt a fatal blow to the mature Harappan cityand forced the inhabitants to abandon the settlementbecause the already tattering financial condition didnot enable them to undertake large-scale damagesthat have been wrought.

It is necessary to state at the outset that the signaturesof all the three devastative earthquakes are bestevident in the castle, which was the most important,most attractive and towering component of theHarappan settlement. A deep gully cut by the rainwater across the southern arm of the fortificationwall of the castle was considered to make a deepprobing with a view to obtaining a cultural sequencevis-à-vis growth of defences which incidentallyprovided evidence for successive earthquakes, atleast the first two.

S16: IGCP Session on Archeoseismology

Conveners: Prof. Manuel Sintubin and Dr. Javed Malik.

THEME

The session on Earthquake Archaeology in Central and Southern Asia invites case studiesthat consider the principles and/or practices of archaeoseismology within the broaderHimalayan seismic zone in Central (e.g. Afghanistan, Tadzhikistan, Kyrgyzstan, Tibet)and Southern Asia (e.g. India, Pakistan, Nepal, Bangladesh). This session is organizedin the framework of the international geosciences programme IGCP567.

11322 - 24 January, 2011


First earthquake occurred towards the closeof the cultural Stage II, possibly sometime after2900 BCE. Its signatures are found in theoccupational strata, deposited against thefortification walls of the first two stages. Allthose layers show two vertical breakages andas many dislocation, i.e. subsidence, morepronouncedly in those floor layers which weremade of compact earth or clay. All strata slightlyslid towards north causing a small bulge a littlefurther where two mud-brick walls of twodifferent stages worked as bulwark.Furthermore, both the houses walls wereconsiderably impacted, so much so their bricksgot badly crushed.

Second earthquake was far more devastative.It brought about end of Stage IIIA, sometimearound 2700 BCE, when the mature Harappanswere yet to arrive on the scene. A large chunk,measuring 7.60 m wide, of which 2.80 m heightis now extant, collapsed and slipped away.Additionally, 4.00 m wide portion of the wall,behind the collapsed part, got partly dislodgedand smashed or deeply fissured. The latter maystill be seen behind the later reconstruction. Thiseffected part which was retained still showdislodgment, smashing and slipping of brickwork. A horizontal cross section portion of thusimpacted wall has shown multiple cracks runningalmost parallel in E-W direction, which arereflected on the vertical section as well.

Another piece of evidence of this occurrencewas seen beside an inner bastion.

The southern face, of this structure collapsedand its stone were found lying helter-skelterduring excavation.

Tell-tale marks of this visitation could be seenelsewhere too.

Third earthquake resulted in the end of themature Harappans’ stay at the site, somewhereduring 2100-2000 BCE. It caused tremendousdamage to the gates of the castle. Particularly,the north gate retained the impact in the formof tilting and arching of the enormously thickinner walls while the outer ones seem to havecollapsed at the first tremor itself.

In the southern arm of the castle, a 6.30 m partof the wall slipped from the top.

The quake must have razed most of theresidential houses down to the ground. But theevidence was hard to find because the laterHarappans, who came to occupy the site aftera gap of many decades, had collected the stonesand even robbed the pre-existing ruins to buildtheir defences and houses, thus obliterated thesigns of the damage.

Here, its seems worthwhile to recall that all thehouses of the ultimate phase, so far excavatedat another Harappan site, Juni Kuran in theKhavda Bet (Kachchh), were found to havebeen collapsed towards the south.

This is the observation and interpretation of anarchaeologist who knows a little of seismology.

S16_IGCP-C1

Archaeological Evidences for a 12th -14th

Century Earthquake at Ahichhatra, Barreilly(U.P.), India

Bhuvan Vikrama1 (E-mail: [email protected]),S. Sravanthi2 (E-mail: [email protected]),Javed N Malik3 (E-mail: [email protected]),Onkar Dikshit4 (E-mail: [email protected])

(1Archaeologist, Archaeological Survey of India,Agra., 2PhD Student, Department of CivilEngineering, IITK, Kanpur., 3Associate Professor,Department of Civil Engineering, IITK, Kanpur,4Professor, Department of Civil Engineering, IITK,Kanpur)

In India archaeo-seismology is still in its infancy,despite the claim of the earliest archaeologicallydated earthquake at Kalibangan was made as earlyas 1963-64. This and such other claims weresupported more by wishful thinking and surmisesrather than by varied and numerous archaeologicalevidences.

Recent excavations at Ahichhatra, located in theUpper Gangetic Plain in the wet-lands betweenHimalayan foothills and river Ganga, have revealedevidences which may indicate towards an earthquakeevent causing proverbial end to the dwindling city.Recent paleo-seismic investigation in the Central and


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North-West Himalayan Foothills suggestsoccurrences of a few major paleo-earthquakesduring 1000 AD-1500 AD (Lave et al., 2005; Kumaret al., 2006; Malik et al., 2008). It has been suggestedthat ~1100 AD a major earthquake occurred alongMain Frontal Thrust with a surface rupture of about200 km – 300 km along the strike of the fault in thefoothill zone (Lave et al., 2005). Another set of eventsare been reported to have occurred during 984 AD-1433 AD around Ramnagar in Central Himalaya(Kumar et al., 2006) and along North-WestHimalayan foothills during ~1400-1500 AD (Kumaret al., 2006; Malik et al., 2008). Thus the majorearthquake events those occurred during 1100 AD-1400 AD were responsible for the destruction of theAhichhatra and in particular probably the 1278-1400AD events (?) from Ramnagar located about 120km from Ahichhatra contributed to total destructionof the site.

This paper envisages to list all such evidence fromAhichhatra and test them on the whetstone of thereasoning and archaeo-seismological parameters. Anattempt will be made to date the eventarchaeologically and understand the relationship tothe paleo-earthquake event.

S12_IGCP-C2

Active Fault Influence on the Evolution ofLandscape and Drainage: Evidence fromLateral Propagation of a Branching Out Faultalong Himalayan Front and Deflection of DabkaRiver, Kumaun, Himalaya

Javed N. Malik (Email: [email protected], Ph:91-512-2597723, Fax: 91-512-2597395), Sambit P.Naik, A. A. Shah and N. R. Patra (Departmentof Civil Engineering, Indian Institute of TechnologyKanpur, Kanpur -208016. Uttar Pradesh, India

The geomorphology and drainage patterns in an areaof active fault and related growing fold providesignificant information on the ongoing tectonicactivity. The Kaladungi fault, an imbricated thrustfault of Himalayan Frontal Thrust (HFT) systemprovides one such excellent examples of forwardand lateral propagation of fault and related folding.This fault has displaced the Kaladungi fan surfacealong it, which is well revealed by variable heightsalong the front. In the east, the uplifted fan surface

is much higher (~140 m) as compared to the west(~60 m). The variation in heights along the fault linecan be attributed to the lateral propagation of fault-fold towards northwest. The northwestwardpropagation of the Kaladungi fault has resulted intodiversion of the Dabka River. A marked diversion ofthe modern Dabka River along its present coursefrom east to west direction can be traced betweenthe Pawalgarh and Karampur towns covering adistance of about 7-8 km. The diversion of DabkaRiver can well be justified by the existence of paleo-wind gap through which it flowed earlier in the recentpast. The wind-gap is characterized by about 1-1.5km wide incised valley extending in NE-SWdirection from Pawalgarh right up to the front

From our studies we conclude that initially the tectonicactive propagated forward along the Kaladungi fault,and then the fault started propagating laterally towardswest causing diversion of the Dabka River.

Keywords: Active fault; lateral propagation;River diversion; Dabka River; Central Himalaya.

S16_IGCP-C3

Signatures of active faulting in SouthernPeninsular India

Biju John, D.T. Rao, Yogendra Singh and P.C.Nawani (National Institute of Rock Mechanics,Kolar, Karnataka)

Peninsular India was considered as seismically stableuntil the most devastating 1993 Latur Earthquake(M=6.3) occurred in this region. Most of the sourcezones in peninsular India could not be identified beforebigger earthquakes, mainly due to their longrecurrence intervals. Thus it is important to identifysuch source zones through geological andgeomorphological studies. Recent studies in theregion south of Palghat Cauvery shear zone,identified two NW-SE trending source zones viz.Desamangalam and Periyar faults, in the WesternGhat region based on the geological andgeomorphological evidences.

In the present study another possible NW-SEtrending source zone is identified in a flat terrain inthe southern Tamilnadu, where most of the drainagesare seasonal. Regionally this lineament is sympatheticto Achancovil shear zone of Pan African orognesis

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(700-500 Ma). The major drainage of the area,Karamaniyar River, is flowing along the part of thislineament in the study area. The trace of the fault isvisible both in crystalline and Miocene formationsand is associated with distinct geomorphic featureson either side. In the east coast, this fault shows anelevated perturbation of southwestern portion oflandmass towards sea whereas beach rocks are notexposed in the northeastern side of the land mass. Amajor drainage seems to be abandoned in thesouthwestern block of the fault whereas a big naturalpond developed in the northeastern block in the studyarea. Our field studies identified a zone of fracturedlaterite extending beyond 500m in the hard capping(vermicular laterite) of the crystalline rocks. Thedeformation zone is charaterised by open cracks aswell as reverse movement where no further leachingafter the fracturing. This may indicate that thefracturing might have occurred after ending of thelaterization process. The style of the deformationexhibits similar to that of surface rupture associatedwith Latur Earthquake and may be indicating theprevalence of compressive tectonic regime even atthe southern end of Peninsular India.

S16_IGCP-C4

Macroseismic Intensity Assessment of 1885AD Historical Earthquake of NW KashmirHimalaya, Using ESI Scale

Bashir Ahmad (E-mail:[email protected]), G.A. Mukhtar #,A.S. Mahmood$ (* Department of Education,J&K, Srinagar, India # Jammu and KashmirPower Development Corporation, Srinagar, India $Directorate of Tourism, Jammu and Kashmir,Srinagar, India)

Kashmir Valley having long history of 5,000 yearsprovides a sketchy picture of historical earthquakes.In all we collated details of 18 earthquakes from thehistorical scribes. While most of the earthquakes mayhave their epicenters outside the Kashmir Valley, andfew which caused severe demage to life and propertyand were associated with ground ruptures and longperiods of aftershocks seems to have been appearedwithin the Valley. Of these, only 1885 AD event iswell documented. We analyse environmental effectsof this ruinous earthquake which occurred along PirPanjal range of NW Kashmir Himalaya in the early

morning (5.00 a:m) of 1885 AD. The present attemptenvisages to implement ESI 2007 macroseismicintensity scale where in archival sources have beenconsulted. The effects (primary and secondary)induced by 1885 AD event to the environment revealsthat intensity would have been VIII–IX on ESI scalewhich correspond to 8.75–9.5 on RF scale andprobably 5.3–6.7 on Richter scale. It has been furtherinferred that the intensity must have been variableall along the Epicentral tract (severe at Baramullaless at Srinagar) because of the severity of demagedecreasing from NW to SE direction.

S16_IGCP-C5

Fault segmentation and propagationcharacteristics based on rupture patterns andslip distribution along the 1957 Gobi-Altayearthquake rupture, Mongolia

Jin-Hyuck Choi1, Kwangmin Jin1, AmgalanBayasgalan2 and Young-Seog Kim1

(E-mail: [email protected]) (1GSGR, Dept. ofEarth Environmental Sciences, Pukyong NationalUniversity, Busan 608-737, Korea., 2School ofGeology and Petroleum Engineering, MongolianUniversity of Science and Technology (MUST),Ulaanbaatar, Mongolia.)

The 260km-long surface rupture associated with the1957 Gobi-Altay earthquake (Mw=8.1) occurredalong the WNW-ESE or EW-trending Bogd left-lateral strike-slip fault in SE Mongolia. Some dip slipswere reported around the secondary thrust andnormal faults locally developed along the fault.However, detailed study on slip distribution, faultsegmentation and propagation along this rupture hasnot been carried out. In this study, geomorphologicand geological investigations including measurementof the amount of horizontal- and vertical-slips arecarried out to interpret rupture patterns andcharacteristics of slip distribution.

Based on the earthquake information, the surfacerupture was initiated near the western end of therupture and propagated unilaterally eastwards. Theleft-lateral slip along the rupture up to 7.0 m andwith 3.5-4.0 m of average displacement. Althoughthe Bogd rupture propagated through manygeometrical oversteps, abrupt changes of slipoccurred only at three oversteps. Based on the


116 22 - 24 January, 2011

rupture patterns and slip distribution, the Bogd surfacerupture is composed of three segments; North-Ih,East-Ih and North-Baga Bogd segments from westto east. The eastern tip damage zone is characterizedby widely developed minor ruptures (conjugate faults,mole tracks, and tension cracks) with smalldisplacements (less than 1m) rather than the westerntip zone.

The slip distribution pattern indicates that overstepsact as barriers against rupture propagation. Thissupports that structural maturity of step-over zoneis one of the main controlling factors on rupturepropagation. The asymmetric tip damage pattern isalso well consistent with the unilateral propagationof the 1957 earthquake. Slip distribution indicatesthat the easternmost overstep acted as a strongbarrier, and the displacement is decreased and theeastern tip damage structures may be developed toaccommodate the releasing stress.

Detailed analyses on the 1957 earthquake rupturepatterns and slip distribution indicate; 1) minorruptures are concentrated at fault linkage and tipzones, and their damage patterns strongly resemblethe suggested fault damage model, 2) characteristicsof step-over zone highly affect fault propagation andtermination. These results indicate that faultsegmentation and propagation are very importantfactors to fault damage patterns and amount of slipalong earthquake ruptures.

S16_IGCP-C6

Preliminary study on active faults aroundMandi region, NW Himalaya, India

Javed N. Malik (Email: [email protected]),Santiswarup Sahoo (Department of CivilEngineering

Indian Institute of Technology, Kanpur-208016, UttarPradesh, India.)

The Mandi area in Himachala Pradesh falls undermeizoseismal zone of 1905 Kangra earthquake innorthwest Himalaya. Preliminary satellite photointerpretation revealed offset of streams, linearvalleys and occurrence of fault scarps along theNNW-SSE striking faults with right-lateral sense ofmovement near Mandi and Marathu villages. Mostprominent stream offsets were considered near

Mandi and Marathu areas to calculate the slip ratealong the faults in both the segments. In order tocalculate the slip rate, the offset ratio (a=D/L) assuggested by Matsuda (1975) was used, where D –is the offset of the streams along the faults and L –is the upstream length of the respective stream. Theaverage slip rate along both the segments is about4.9 ± 0.15 mm/yr. The preliminary identification ofactive fault trace extending for about 20 km suggeststhat this fault can produce an earthquake of M>6.5.Further studies are in progress, which will be greatsignificance towards better evaluating the seismichazard of this region.

IGCP-C7

Archaeology of Earthquakes at Mahasthanghar(Province of Bogra, Bangladesh)

Bruno Helly1, Ernelle Berliet2, BarbaraFaticoni3 (1 Directeur de recherche au CNRS(émérite), membre de la Mission franco-bangladaisede Mahasthanghar, Maison de Orient et de laMéditerranée Jean-Pouilloux, Université de Lyon, 7,rue Raulin, F 69007 LYON (France).,2Archéologue,membre de la Mission franco-bangladaise deMahasthanghar, École Française d’ExtrêmeOrient,Bangkok.3Archéologue, membre de laMission franco-bangladaise de Mahasthanghar,Université La Sapîenza, Rome (Italie)).

At about twenty miles northwest of the present townof Bogra, north of the confluence of the Ganges andBrahmaputra, is the ancient walled city ofMahasthan. Beyond the fortifications, the suburbanarea from ancient times spread over a radius of 8 to9 km outside the walls, with theexception of theeastern side limited by the course of Karatoya, ariver that has largely contributed to the prosperity ofthe city and which also marks the limits of expansionof the site. A high brick wall, surrounded by a roaddefines urban space itself about 1.5 km long by 1km wide. The remains of the ancient city werediscovered and identified for the first time by F.Buchanan Hamilton, 1808.But it was not until 1879that Sir Cunningham identifies Mahasthan as theancient city of Pundranagar reported by the texts.The first regular excavations at Mahasthan wereconducted between 1928 and 1933, then sporadicallyuntil 1936, by the Indian archaeologist K.N. Diksit

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of the Archaeological Survey of India.

The latest research at Mahasthan is developped asa cooperative program run by a Franco-Bangladeshsince 1993 under the direction of Jean-FrançoisSalles. The early campaigns (1993-1999)concentrated on an area called “Rampart East”aimed at establishing the whole stratigraphicsequence and timing of the city and its evolution.The layers were well preserved since the oldestdating in IVe century BC levels until the latest datingfrom around the twelfth century AD. In view ofanalyzing the levels of medieval and modernoccupation, an excavation program was launched in2001 in south-eastern city on the plateau of Mazar,the highest point of the city. They revealed aresidential area which corresponds to the last periodof occupation of the site and whose remains offerclear traces of violent and simultaneously destructionthat can probably be attributed to an earthquake.Recent campaigns (2005-2010) on the wall that limitsthe area of the city have helped to clarify thishypothesis and to refine the chronology of events :the construction of this wall in the oldest period, thesuccessive phases of reconstruction, particularlyafter a siege of a rare intensity, and finally the finalphase of a wall hastily restored before beingpermanently ruined by the earthquake that endedthe history of the city.

À une vingtaine de kilomètres au nord-ouest del’actuelle ville de Bogra, au Nord de la confluencedu Gange et du Brahmapoutre, s’élève ville fortifiéede Mahasthan. Au delà des fortifications, l’espacesuburbain des temps anciens s’étend sur un rayonde 8 à 9 km hors les murs, à l’exception de la faceorientale limitée par le cours de la Karatoya, unerivière qui a largement contribué à la prospérité dela ville et qui marque également les limites del’expansion du site. Un haut rempart de briques, bordéd’un fosse (douve ?), délimite l’espace urbainproprement dit sur 1,5 km de long par 1 km de large.Les vestiges de l’ancienne cité ont été découvertset repérés pour le première fois par F. BuchananHamilton, en 1808. Mais ce n’est qu’en 1879 queSir Cunningham identifie Mahasthan comme étantla ville antique de Pundranagara relatée par lestextes. Les premières campagnes de fouillesrégulières à Mahasthan ont été menée entre 1928 et1933, puis de manière plus sporadique jusqu’en 1936,

par l’archéologue indien K.N. Diksit del’Archaeological Survey of India. Les recherchesles plus récentes s’inscrivent dans le cadre d’unprogramme de coopération mené par une équipefranco-bangladaise depuis 1993, sous la direction deJean-François Salles. Les premières campagnes(1993-1999) concentrées sur un secteur nommé «Rempart Est » visaient à établir l’ensemble dessequences stratigraphiques et chronologiques de laville et de son évolution. Les couches étaient bienpréservées depuis les plus anciennes remontant auIVe s. av. jusqu’au niveau datant des environs duXIIe siècle ap. J.-C. Dans la perspective d’analyserles niveaux d’époque médiévale et moderne, unprogramme de fouilles a été lance en 2001 au sud-est de la ville, sur le plateau de Mazar, le point leplus élevé de la ville. Ils ont révélé un quartierd’habitation qui correspond à la dernière périoded’occupation du site et dont les vestiges portentclairement les traces d’une destruction violente etsimultanée que l’on peut probablement attribue r àun séisme. Les campagnes récentes (2005-2010) surle rempart qui limite ce secteur de la ville ont permisde préciser cette hypothèse et d’affiner lachronologie des événements : la construction de cerempart dans la période la plus ancienne, les phasesde reconstruction successives, notamment suite àun siège d’une rare intensité, et enfin la phase finaled’une muraille hâtivement restaurée avant d’êtredéfinitivement ruinée par le séisme qui a mis fin àl’histoire de la cité.

S16_IGCP-C8

Archeoseismology of the A.D. 1545 earthquakein Chiang Mai, northern Thailand

Miklos Kazmer1 (E-mail: [email protected])and Kamol Sanittham2 (1Department ofPalaeontology, Eotvos University, Pazmany Petersetany 1/c, H-1016 Budapest, Hungary.2Department of Mathematics and Statistics,Chiangmai Rajabhat University, Chiang Mai,Thailand)

The A.D. 1545 Chiang Mai earthquake in Thailandis one of the few ancient seismic events, when bothhistorical documentation and the hard evidence, „thesmoking gun” is available. We studied the Buddhisttemples in and around the old city of Chiang Mai to


118 22 - 24 January, 2011

identify possible earthquake-induced damagespreserved in the buildings’ structure and orientation.The earthquake occurred on 28 July 1545, in theafternoon hours between 4.30 and 6.00 pm.

The well-known Wat Chedi Luang – highest chediever built on the alluvial soil of the Chiang Mai-Lamphun Basin – has lost about half of the original80-metres height, due to southward-directedcollapse. We visited further seventy-four temple sitesin search for earthquake-induced damages. Twenty-one sites display tilting of the chedi, up to 5°systematically either in northward or southwarddirection. Data for pre-1545 construction of templesare mostly available. We suggest that a city-wideliquefaction event occurred related to the A.D. 1545earthquake. North-south-directed strong motiondestroyed the Wat Chedi Luang, and affected other,significantly smaller buildings of different vibrationcharacteristics. An area of at least 4 km2 sufferedliquefaction extended on the Ping River alluvial plain,where ground-water level is often less than 1 m belowground.

Liquefaction is mostly attributed to nearby epicentres(within 3-4 km). We suggest that the activity of thenearby Doi Suthep fault westward of Chiang Maicity is responsible for both the desctruction of WatChedi Luang and the liquefaction-induced tilting ofmany other chedis in the area.

The Doi Suthep low-angle normal fault is currentlyregarded as inactive. It is the western master faultof the half-graben of the Chiang Mai Basin. ItsMiocene activity produced the km-thick sedimentarysuccession of the basin, while allowing the uplift ofthe Tertiary metamorphic core comples of DoiSuthep. Its continued activity in the Holocene isevidenced by the extensive alluvial plain of Ping Riverextending westwards just to the foot of Doi SuthepMountain.

Currenty earthquake activity in northern Thailand ininterpreted within the framework of Thoen Fault(Chiang Saen, May 2007, ML = 6.3), Mae Tha andPha Youv fault zones tens of kilometres away. Sincerecurrence time of major earthquakes seems to belonger than the instrumental period of 50 years,archaeoseismology is a necessary tool to extend theobservation period to centuries.

S16_IGCP-C9

Paleoseismological analysis in north ofDushanbeh, Tajikistan

H. Nazari, 1,2 M. Qorashi,2 A. Ibrohim,3 M.Shokri,1 A. Fathian,1 R. Juroyov3 and B.Oveisi1 (1Geological survey of Iran,Seismotectonic group, P.O. Box 13185-1494,Tehran, Iran., 2Institute for Earth Science,Geological survey of Iran, P.O. Box 13185-1494,Tehran, Iran.,3Geological Survey of Tajikistan

Dushanbeh, capital of the Tajikistan with 680,000population, Standing at south of the Hissar range thatis surrounded by several active faults. Height of theHissar with WNW-ESE trend are including ofmetamorphosed and nonmetamorphosed rocks ofPaleozoic to Mesozoic that are covered by Neogenedeposits in south of Dushanbeh.

Regard to morphotectonic features and lack ofinstrumental and historical earthquakes in this area,it is necessary to know about active faults and pastseismicity of them for a better perception of seismichazard in Dushanbeh city. paleoseismology is oneapproach that we can use for this purpose.

In this study we used satellite imagery (Spot; withpixel size 2.5m, SRTM data with 90m resolution),digital topographic model made by kinematic GPSand field observation during June 2010 to identifygeometry and kinematic patterns of the mostimportant fault near the Tajikistan capital.

In order to identify paleo events, we dug two trenchesat north of sheikhan village along an active scarp.Measured apparent Vertical and leftlateraldisplacement on a ridges axis are 19 and 12 mrespectively. Trench 1 with 33m in length, 1.5m wideand ~3.5m high, located in N 38Ú 372 52.83 , E68Ú 542 32.73 . Trench 2 in downstream of trench1, with 15m in length, 1.5m wide and ~3.5m high, islocated in N 38Ú 372 49.83 , E 68Ú 542 31.53 . Sixand three units observed in the eastern wall of thetrench 1 and 2 where the trenches dug in cream tolight brown loess deposits respectively.

Our field observation and drown logs on the trench1 and 2 allow us to interpret 2-3 paleo earthquakesdue to reactivity of an active fault on this studiedarea.

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Keywords: Paleoseismology, Trench, event,Dushanbeh, Tajikistan

S16_IGCP-C10

Archaeoseismological approach based on stoneheritages in Gyeongju, SE Korea

M. Lee and Y.-S. Kim* (E-mail:[email protected].)(Dept. of Geosciences,Pukyong National University, Busan 608-737,Korea)

The Korean peninsula is located within therelatively safe Eurasian intracontinental region.However, in some neighbouring countries aroundKorea such as Japan and China, big earthquakeshave occurred frequently. However, according to theKorean historical records, some big seismic eventsaffected Korea peninsula. Furthermore, over 20quaternary faults are recently discovered along theYangsan and Ulsan faults located in south-easternpart of Korea.

Gyeongju, which is located between these faults, isrepresented as an oldest capital city in Korea.Therefore, there are many cultural heritages andhistorical records to study on. According to thehistorical records, the Gyeongju area has experiencedseveral big earthquakes, which have resulted inextensive damages to the heritages. Deformed man-made structures with recognized age and originalstate can offer supplementary information on pastearthquakes.

For this study, we will apply the EarthquakeArchaeological Effects (EAE) - ESI07 macroseismicscale - and statistic analysis on destroyed stoneheritages such as pagodas and ramparts. In addition,we will collect historical and instrumental earthquakedata to figure out the characteristics of the pastseismic activity in Korea. This study can give someuseful information to paleoseismic and earthquakehazard studies in Korea.

S16_IGCP-C11

Discover and the Characteristic Initially Searchof Gaixia Ruins’s Nature Distortion Vestige,Guzhen County, Anhui Province, P.R.China1

YAO Da-quan(Seismological Administration ofAnhui Province, Hefei,Anhui P.R.China,230031,E-mail : [email protected])

During recent years, with the large-scale economicconstruction in Eastern China, such as highway, high-speed railway and other major projects underconstruction have excavated a large number ofancient sites, ancient tombs, which make it possibleto identify and trace for thousands of years of naturaldeformation history in Eastern China.

Recently, the earthquake department with the culturalrelic archaeology department cooperation, to conductthe special excavation research to Anhui GuzhenGaixia ruins archaeology scene, the fault and thecrack are discovered .The preliminary study todemonstrate both for the different time stratumdislocation event’s vestige, and the timeapproximately to be equal to the Dawenkou culturestage.

The fault and crack located in the same culture layer,displaying tension deformation, which occurred inthe culture layer of the plastic clay soil, should bethe fast fracture remains, and in particular, themovement traces of the upwards flow of sand alongthe crack as the flame appearance, shows a typicalstick-slip mark. According to the combination of thecultural relic pieces of the culture layer, this culturelayer belongs to the Late Dawenkou Dynasty. Butthey still show difference: The fault is a tensile shear,showing tension shear fracture; the crack is tensile,showing tension cracks; They ended in the bottomof the different overlaying cultural layers. The timeof the crack formed was earlier, and may representtwice stick-slip events. The specific time is to beproven by further study. To analyze theseismogeology environment of the vestige, thelocation lies on Tancheng-Lujiang fault in NNEtrending. According to the history records, severalearthquakes of Ms6 occurred near this area. Ourdiscovery of this earthquake ruins enriches the newdeformation activity in this area.4 This paper is a contribution to Scientific ResearchSpecial Project of the Earthquake Calling(200808064) and Science and Technology TackleKey Problem Plan Project of Anhui Province(08010302204)


120 22 - 24 January, 2011

S16_IGCP-C12

Paleo-earthquake evidence from archaeologicalsite in mesoseismal zone of 1819 Allah Bundevent, Great Rann of Kachchh, Gujarat,Western India

Malik J N1, Gadhavi M S3, Ansari K.1Dikshit O1, Chiranjeeb Banerjee1, FalguniBhattacharjee2, A. K. Singhvi4 and B. K.Rastogi2 (1Department of Civil Engineering,Indian Institute of Technology Kanpur Email:[email protected], 2Institute of SeismologicalResearch, Gandhinagar, 3L. D. College ofEngineering, Ahmedabad, 4Physical ResearchLaboratory, Ahmedabad)

The Kachchh region in seismic zone V is not onlywell known for the occurrence of large magnitudeearthquakes occurred in 1668 (M7); 1819(M7.7±0.2), 1956 (Ms6.1), and 2001 (Mw7.6), butalso for having major Harappan (4000-4500 year)and historical sites. One of such major sites wasDholavira located on Khadir Island. Few sites inGreat Rann of Kachchh (GRK), probably flourisheduntil 1819 Allah Bund earthquake (?). Till date it isnot fully understood as whether these sites wereaffected by the major seismic events in the past andalso the presently evolved landscape was influencedby tectonic movements. The geologists,archaeologists, and scholars of ancient Indian history

have mentioned the existence of numerous mightysouthwest flowing rivers viz. the Sindhu (Indus),Shatadru or Nara (Sutlej) and Sarasvati, during Pre-Vedic and Vedic times (~4000 yr). These riversflowed into then existing Arabian Sea, presently theGRK.

We excavated 6-8 trenches in Allah Bund regionGRK. Study reveals occurrence of at least 3 majorevents during recent past, which were probablyresponsible for the disruption of major channels (?),changing the landscape and destruction of thesettlements. Trenches on the hanging wall of ABFshows thick massive yellowish medium-fine sandoverlain by 1-1.5 m thick laminated sequence of silty-sand and clay. This suggests change in depositionalenvironment from fluvial to fluvial-marine or tidalenvironment (high sea-level during 4000-6000 yr?).Trench at Vigukot revealed prominent sand-sheetsat three levels indicative of 3 major liquefactionevents, triggered by near source earthquakes, thelatest event probably be the 1819 Allah Bund.

Preliminary OSL ages of the sediments dated fromthe sand blow, soft sediment deformationalstructures, faulted sedimentary units from thetrenches excavated on the hanging wall and acrossthe Allah Bund Fault suggests occurrence of at least2-3 events during 2.0-3.0 ka, with the most recentevent during 2.0 ka.

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M_P1

Specific Yield-Water Level Fluctuation Methodan Effective Tool for Quantitave Evaluation ofGroundwater Resource – A Case Study

Syed Zaheer Hasan (Gujarat Energy Researchand Management Institute, 203, IT Tower-1,Infocity, Gandhinagar-382009, Gujarat, India.India. E-mail: [email protected]) andM. Yusuf Farooqui (Gujarat State PetroleumCorporation Ltd., GSPC Bhavan, 3rd Floor, NorthWing, Sector-11, Gandhinagar-382011, Gujarat,India. E-mail: [email protected])

The area under study, Kasganj sub-division, districtEtah, Uttar Pradesh, represents a part of Ganga-Kali interfluves characterized generally by a flattopography barring some uplands and low valleys.Covering an area of 1175 sq. km, the area falls underthe sub-tropical climatic zone of India where therainfall forms the principal source of groundwaterrecharge besides, the seepage from canals andirrigation return flow. The mean annual rainfall inthe region is 755mm. The pre and post-monsoondepth to water level and fluctuation maps show awide variation over the entire region correspondingto the surface topography and lithological controlrespectively. The Quaternary alluviumunconformably rests over Neogene sediments, whichis unconformably underlain by the lower BhanderLimestone and continues upto the BundelkhandGranite. The study shows that the groundwaterrecharge through canal seepage is 71.23MCMwhereas; through irrigation return flow it is45.77MCM and the monsoon recharge is171.08MCM. The net annual recharge is230.95MCM and the net draft is 135.25MCM thus,leaving a balance of 95.70MCM as utilizableresource for future development. The stage ofgroundwater development is 58.56%, which showsthat the area falls under the safe category.

Keywords: Groundwater development,groundwater recharge, canal seepage, irrigationreturn flow, monsoon recharge, groundwaterdraft and groundwater resource evaluation

M_P2

Environmental studies using ElectricalResistivity Method

Sunita Devi & Rupal Malik (Institute ofSeismological Research, Gandhinagar, India.E- mail: [email protected],[email protected])

Ground water is one of the basic needs of the humanbeings for their survival on the earth. With thedevelopment, it is being polluted because of theaddition of the chemicals into seas, rivers & lakes.The impact of pollutants like solid & liquid wastesproduced by different source (domestic & industrial),pesticides used in agriculture on our environment canbe studied by resistivity survey.

We have used the Electrical method for this purpose.The objective was the environmental studies in thearea. For this purpose, the data was acquired in theKurukshetra University, in Haryana near the canal& at dump site. The data was acquired using Wennerconfiguration using 2m electrode spacing. Aftercollecting, the data was interpreted using RES2divsoftware. The resistivity values came out to be ofthe order of 12.0 – 47 ohm-m. The resistivity valueswere low near the surface & up to depth 4.0 m.these low values were due to seepage from canalthereby increasing moisture content, leading to lowvalue of resistivity. Near the dump site, the surveywas done using wenner configuration & the resistivityvalues vary from 14.0 to 100.0 ohm-m. the highvalues are due to dryness in the area & brokenbuilding material . In the near surface the resistivityvalues were low in the range 10.8 to 16.4 ohm-m.Thus the resistivity method helps in the environmentalstudies.

MISCELLANEOUS


122 22 - 24 January, 2011

ISES Lecture

Program on Study of Earthquake Precursorsin India

Harsh Gupta (Panikkar Professor, NationalGeophysical Research Institute,(Council ofScientific and Industrial Research)Hyderabad500007, India.)

A National Task Force for earthquake precursorystudies was set up by the Department of Scienceand Technology, Government of India to take stockof the efforts and the progress made so far in thearea of earthquake precursory studies andformulation of a focused program, relevant to IndianContext.

A series of meetings were held and the global efforton study of earthquake precursors was examined.A note was made of the precursors observed by theIndian scientists, and success in medium termforecast in the North- East India region, and shortterm forecasts in the Koyna region of artificial waterreservoir triggered earthquakes. Keeping in mind thelarge Indian Territory and that Himalayan region isparticularly vulnerable to frequent damagingearthquakes, the following approach is suggested:

1. Identify a few areas (4 to 5) where a fewprecursors (such as swarms and the followingquiescence) have been observed and there is agood probability of an earthquake (Me”6) tooccur, particularly in the Himalayan region.

2. 4 hubs are proposed for concentratedobservations of all possible precursors byconcerned agencies/laboratories/universities.These are:a. RRL, Jorhat for NE Himalayab. WIHG, Dehradun for NW Himalayac. IMD, Central Himalayad. NGRI for Koyna and one or two other

locations in Himalaya3. In these identified areas concerted efforts by

various partners to monitor all possibleprecursors.

4. Operate multi parametric observatories at a fewselected locations.

5. Look into the possibility of setting up a 15 to 20element SODAR system to cover the entire(2000km) range of Himalaya to monitortemperature in the 5-6 km layer of theatmosphere for monitoring possible thermalanomalies.

6. Solicit and develop satellite projects formonitoring the precursors.

7. Meet frequently (every 3 months) to monitorthe progress.

It is also suggested to prepare earthquake scenarios,if the past damaging earthquakes repeat.

An additional issue is to set up rapid forecast ofanticipated accelerations soon after a majorearthquake occurs in the vicinity of a metropolis,particularly New Delhi, the capital of India whichlies in the vicinity of the Himalayan earthquake belt.

Special - 1

Shailesh Nayak (Secretary MoES, Govt. of India)

Special - 2

India’s Tsunami Warning System: A SuccessStory

Harsh Gupta (Panikkar Professor, NationalGeophysical Research Institute,(Council ofScientific & Industrial Research) Hyderabad-500606, INDIA.E-mail: [email protected])

The recent Indian Ocean Tsunami (December 26,2004), is now established to be the strongest in theworld over the past 40 years. It resulted indevastations amounting to national calamities inseveral parts of the Indian Ocean. As compared tothe most severe Tsunamis of the past, the loss oflives in the Indian Ocean Tsunami has been higherby an order of magnitude, thereby calling fordevelopment of Tsunami Warning System on a war-footing.

The coastal population being the victims of stormsurges and tsunami, it is obvious that the systemsfor their mitigation have several commonalities (interms of observational network, data base onbathymetry and coastal topography, data

SPECIAL LECTURES

12322 - 24 January, 2011


communication, dissemination of warnings, trainingand education, operational practices) and hence it isprudent and cost-effective to address them together.India planned for development of an integratedmitigation system for the oceanogenic disasters viz.Tsunami and storm surges in the northern part ofIndian Ocean region with an ultimate goal to savelives and property.

The design of the System is based on end-to-endprinciple, involving i) mean real time estimate ofearthquake parameters, ii) assessment whether atsunami has been indeed generated throughdeployment of ocean bottom pressure sensors andtide guages, iii) numerical modelling for tsunami,storm surges with all associated data inputs, iv)generation of coastal inundation and vulnerabilitymaps, v) development of Tsunami Warning Centreat INCOIS, Hyderabad and its operation on 24x7basis for generation of timely advisories forimplementation, and vi) capacity building, education,and training for all stakeholders.

The Project has been implemented by theDepartment of Ocean Development (now Ministryof Earth Sciences) through its Institutions, with activeparticipation from Department of Science andTechnology, Department of Space, Council ofScientific and Industrial Research, and Universitydepartments. The planning of project started inJanuary 2005. By March 2005 all the details wereworked out and it was estimated that it would beoperational by September 2007. This deadline hasbeen successfully met, and system tested during theoccurrence of tsunamigenic earthquake onSeptember 12 & 13, 2007. Today, this is the bestsystem operating any where in the world.

Special - 3

Time-varying Tsunami Characteristics inWavelet Domain

Ashutosh Chamoli (E- mail: [email protected]);V. Swaroopa Rani, Kirti Srivastava, D. Srinageshand V.P. Dimri (National Geophysical ResearchInstitute, Hyderabad- 500007, India.(Council ofScientific and Industrial Research))

Wavelet theory provides different methodologies tounderstand the signal behavior and interpretation inspace scale domain. In this domain, the time-varyingsignals can be analysed in a unique framework andthe signatures in wavelet domain give optimum time-frequency information. In this work, the seismogramsof different earthquakes are studied using waveletanalysis and characterized for tsunamigenesis. Thefrequency content of the earthquakes is interpretedin terms of rupture duration and slip of theearthquake. The methodology is tested on theearthquakes mainly from Andaman-Sumatra regionand other important earthquakes. The waveletdomain analysis provides a diagnostic method tounderstand the seismogram characteristics.

Special - 4

Making of Probabilistic Seismic Hazard Mapof India for the Bureau of Indian Standards

B.K. Rastogi, RBS Yadav, Babita Sharma andVikas Kumar (Institute of SeismologicalResearch, Raisan, Gandhinagar-382009, [email protected])

Seismic Hazard in term of engineering design isgenerally defined as the predicted level of groundacceleration which would be exceeded with 10%probability at the site which is under considerationdue to the occurrence of earthquake in the region, innext 50 years. This corresponds to a return periodof 475 years meaning in next so many years, theestimated acceleration can be expected. It is alsocalled Operating Basis Earthquake (OBE). Differentprobabilities and return periods are also consideredsome times. The acceleration exceedance map with2% probability in 50 years (return period 2375 years)is called Maximum Credible Earthquake (MCE).

Probabilistic Seismic Hazard Analysis (PSHA)involves three steps:

1) Specification of the seismic-hazard sourcemodels

2) Specification of the ground motion models(attenuation relationships), and

3) Probabilistic calculation.


124 22 - 24 January, 2011

The input parameters that are needed for performinga Probabilistic Seismic Hazard Analysis (PSHA)following the Cornell approach (Cornell, 1968; Reiter,1990) are:

• A seismotectonic source model, which definesfault or areal zones of equal seismic potential.The definition of source zones relies to a largedegree on expert judgment, which is based onthe assessment of the seismotectonicframework, on past seismicity, and onconsiderations regarding the temporal and spatialstationarity of earthquake activity.

• An earthquake catalog, which is used to deriverecurrence rates and to estimate the maximumpossible earthquake for each source zone.

• A predictive ground-motion model (PGMM),which describes the attenuation of amplitudes(acceleration, velocities) as a function ofdistance as well as the scaling of ground-motionas a function of magnitude.

The Indian subcontinent region bound by 50 - 400 Nand 650 - 1000 E has been considered for thepreparation of probabilistic seismic hazard map ofIndia as task given by Bureau of Indian Standards(BIS). The study region consists of India includingAndaman-Nicobar islands and also Pakistan, HinduKush, Karakoram, Tibet and Burma. Based on theseismicity distribution and tectonic features, 31potential seismic source zones were delineated. Theseismotectonic characteristics of these source zoneshave been explained.

A seismicity database has been prepared for theperiod AD 180 to 2008 containing 35302 earthquakes,using all existing catalogues. The prepared seismicitydatabase has been homogenized for momentmagnitude (Mw) with the help of various empiricalrelationships developed among different magnitudescales (ML, Ms, mb and Mw). The 50.14%earthquakes (foreshocks and aftershocks) beingdependent have been removed from the entirecatalogue using the method developed byUhrhammer (1986). In this method, initially a visualanalysis of earthquake catalogue is necessary to

identify the seismic cluster. A spatial and temporalwindowing method is applied to identify theaftershocks and foreshocks from the seismic clusters.The spatial extension (L) of the cluster of aftershocksand foreshocks is estimated using the equation LogL = a * M +, where, a and b are the coefficients ofregression equation. The spatial window has acircular shape with a radius equal to L/2 and centeredon the main event. The duration (T) of the cluster ofaftershocks and foreshocks is counted from the firstevent in the sequence and expressed as a functionof magnitude M through the equation Log T = c * M+ d. where c and d are the coefficients of regressionequation. All events (foreshocks and aftershocks)with epicenters falling within the defined twowindows are removed.

The cut-off magnitude (threshold magnitude ormagnitude of completeness, Mc) for this seismicitydatabase is estimated as Mw 4.5 for interplate(Himalayan seismic belt) region and 4.1±0.17 forintraplate (Peninsular India) region. The completenessperiods for different magnitude ranges are alsoestimated. It is observed that in Peninsular India eventswith magnitude 4.0-4.5 are complete for 80 years,while events for Mw > 4.5 are complete for 200 years.Along Himalayan plate boundary regions catalogue iscomplete for 40 years for magnitude Mw 4.0-5.0; 80years for Mw 5.0-6.0; 100 years for Mw 6.0-7.0; and200 years for Mw Mw >7.0.

Using the clean catalog, the seismic hazardparameters a-value (defining seismicity level), b-value (defining number of large earthquakesexpected w.r.t. smaller ones), Mmax (The maximummagnitude was estimated from past seismicity foreach of zones separately) and return period wereestimated by a computer program written by A.Kijko, which goes as inputs to hazard computation.

The maximum likelihood estimation of earthquakehazard parameters (maximum magnitude Mmaxearthquake activity rate ë and ‘b’ parameter inGutenberg-Richter equation) is extended to the caseof mixed data containing large historical events(extreme catalogue) and recent completeinstrumental data (complete catalogue). Therefore

12522 - 24 January, 2011


to find these hazard parameters we divide theearthquake catalogue into two parts, namely, extremecatalogue and complete part of catalogue. Theextreme part of catalogue, extended to allow forvarying time intervals from which maximummagnitude are selected. Assuming that this part ofthe catalogue contains only the largest seismicevents, and having the possibility of dividing thecatalogue into time intervals of different lengths, thecomplete part of catalogue rejects the macroseismicobservations that are incomplete and uses completepart of catalogue. In Kijko approach it is possible tocombine the information contained in themacroseismic part of catalogue with that containedin the more complete parts of catalogue. Thus, todetermine the seismic hazard parameters (maximummagnitude Mmax earthquake activity rate ë, b–valueand return period) of Indian region we use extremeas well as complete part of catalogue, separately asthe input of Kijko computer program. For example,for Zone1 we divide its earthquake data into extremeand complete part. The earthquake data for this zoneis from 1912 to 2008. From 1912 to 1963 theearthquake data is not complete so we take it asextreme part of catalogue. From 1964 to 2008 theearthquake data is completely recorded. Thus wetake this part of catalogue as complete one. Theoutput of this contains b-value, beta, activity rate,and return period.

After finding the all hazard parameters, the next stepis to prepare a Seismic Hazard map, for this we useprobabilistic hazard assessment approach of Esteva-Cornell, to determining the peak ground acceleration(PGA), which were computed using CRISIS2007software for 10% probability of exceedance in 50years, for Indian region, on a grid of points spacedby an angular distance of 1.0 degrees both in N-Sand in E-W direction. Our basic assumption in theapplication of CRISIS2007 code is a Poissonianmodel of seismic event time recurrence. Anattenuation relationship is used to provide probabilisticestimates of PGA expected at a given distance foran earthquake of given magnitude: at this regard weadopted the relationship obtained by Abrahamson &Silva (1997), Youngs et al (1997) and SEA99 (1997).

Abrahamson & Silva (1997) derived attenuationrelation for the average horizontal and verticalcomponent for shallow earthquakes in active tectonicregions as given below:

log(PGA)= a1 + a2( M-6.4) - a3(8.5-M)2 + { a4 +a5(M-6.4)}LN(R)

where, a1, a2, a3, a4, and a5 are constants, M standsfor given magnitude and R is the closest distance tothe rupture plane in km.

In Youngs et al. (1997), attenuation relation for peakground acceleration for subduction zone earthquakeis determined. The attenuation relation given as,

log (PGA)ij = C1* + C2Mi + C3

*ln[(R)ij + exp{C4* -

(C2/C3*)Mi}] + C5Zss + C8Zt + C9Hi+ çi+ åij

C1*= C1+ C3C4- C3

*C4* ; C3

*= C3 + C6 Zs; C4

*= C4 + C7 Zs

where i is earthquake index, j is the recording stationindex for the ith event, M is moment magnitude, R isthe closest distance to the rupture plane in km, H isfocal depth, Ck, k=1 to k=10 are coefficientsdetermined by regression analysis, Zss indicatesshallow stiff , çi (inter-event component representingearthquake to earthquake variability of groundmotions) and åij (intra-event component representingearthquake variability of ground motions) are errorterms, Zt indicates source type (0 for interface eventsand 1 for intraslab)

While in SEA99 (1997), attenuation relation is derivedfor hard rocks and for soil. Based on seismotectonicfeatures of our 31 seismic zones, we applied thisattenuation relation to these seismic zones.

For zones 1 to 7, zones 9 to 13 and zones 16 to 18,Youngs et al. attenuation is applied. For zones 8, 14,15, 19 20 and 22, Abrahamson and Silva attenuationmodel is applied. And SEA99 attenuation model isapplied for zones 21 and zone 23 to 31. Besides theseattenuation relation as input for hazard computationin CRISIS2007, we take threshold magnitude (i.e.minimum magnitude), upper bound magnitude(maximum magnitude), and all seismic hazardparameters (Beta â, earthquake activity rate ë andb–value) for each seismic zone as an input. The


126 22 - 24 January, 2011

Fig. Seismic Hazard Map of India with Return Period of 475 years i.e. 10% probability in 50 years.The value of PGA is expressed in terms of gal.

hazard map for 10% probability of exceedance in50 years (Fig.) shows that Hindu Kush region havehigh hazard level of order 3.989E+02 gal, followedby Northeast and Burmese arc where hazard levelis 3.20E+02 gal, the northwest Himalaya shows thehazard level up to an order of 1.85-2.05E+02 gal,whereas Tibetan plateau region have hazard levelof order 1.90E+02 gal. In Indian shield region theorder of hazard level is on average 4.25E+01 galwhereas some areas like Kachchh where hazardlevel is up to 1.20E+02 gal and Koyna having hazardof order 1.513E+02 gal. The Andaman-Nicobarregion also shows the high level of hazard of order3.125E+02 gal.

Special - 5

NEW PROBABILISTIC SEISMIC HAZARDMAP OF INDIA

R. N. Iyengar (Centre for Disaster Mitigation,Jain University, Bangalore-Kanakapura Road,Jakkasandra 562112. E-mail: [email protected])

In this talk the new PSHA map of India developedfor NDMA, Govt. of India will be presented. Thetalk highlights how the source, path, site paradigmhas been used to estimate surface level hazard athard rock sites (A-type: Vs > 1.5 km/s). All knowndata about past earthquakes and mapped faults areconsidered to characterize the seismic activity. Basedon the tectonic setting of the country and dispositionof faults thirty-two source zones are identified. Anearthquake catalogue (Mw>4) from the remote past

12722 - 24 January, 2011


till the end of year 2008 is prepared with discussionon issues related to completeness and recurrencerelations.

The country is structured into seven geologicalprovinces with differing quality factors. Finite faultstochastic source mechanism model of Boore is usedto develop new strong motion attenuation relationsfor the above seven regions. Validation of theempirical relations is presented wherever possiblewith available strong motion data. Standard PSHAhas been carried out covering the whole country ona grid size of 0.20 x 0.20. Well established probabilisticanalysis procedure is adopted to compute theprevalent hazard in terms of peak ground acceleration(PGA), short period and long period spectralaccelerations for return periods of 500, 2500 years.Contours of PGA values for 5000 and 10000 yearreturn periods are also mapped.

The results presented can be directly used on A-type rock sites. For other site types, corrections haveto be applied in terms of either modifying factorsprescribed in standard codes (IBC-2009) or bycarrying out necessary soil amplification analysisbased on local geotechnical data. Application thePSHA results is illustrated by working out the designresponse spectra as per IBC-2009 for the fourmetropolitan cities, Delhi, Mumbai, Kolkata andChennai.

Special - 6

RECOMMENDATIONS FOR EARTHQUAKESAFETY AND RETROFITTING IN GUJARAT

Padmashree Dr. Anand S. Arya (FNA, FNAE;Ex-National Seismic Advisor MHA, GoI-UNDP

Professor Emeritus of Earthquake Engineering, IIT-Roorkee, E-mail: [email protected])

India’s high earthquake risk and vulnerability is clearfrom the fact that about 59 per cent of India’s landarea could face moderate to severe earthquakes inseismic III, VI and V. During the period 1990to 2006,more than 23,000 lives were lost in India due to 6major earthquakes, which also caused enormousdamage to buildings and public infrastructure. Theseearthquakes include the Uttarkashi earthquake of

1991, the Latur earthquake of 1993, the Jabalpurearthquake of 1997, and the Chamoli earthquake of1999, followed by the Bhuj earthquake of 26 January2001 and the Jammu & Kashmir earthquake of 8October 2005.The occurrence of several devastatingearthquakes even in Zone III area indicates that thebuilt environment in the country is extremely fragile.All these major earthquakes established that thecasualties were caused primarily due to the collapseof buildings. However, similar high intensityearthquakes in the United States, Japan, etc., do notlead to such enormous loss of lives, as the structuresin these countries are built with structural mitigationmeasures and earthquake-resistant features. Thisemphasizes the need for strict compliance of townplanning bye-laws and earthquake-resistant buildingcodes in India.

For achieving earthquake safety, there is a need toundertake reduction of earthquake risk before thenext earthquake strikes. Disaster risk reduction andits mainstreaming into all development activities hasbecome a subject of utmost importance. Themeasures required to reduce direct, in direct andintangible disaster losses, will have to covertechnical, social or economic action, to be taken bythe various stakeholders. Two aspects of the disasterreduction strategy are i) mitigation involvingmeasures for reducing the impact or effect of theoccurrence of an earthquake, and ii) preparednessmeaning a state of readiness to deal with a threateningearthquake situation and the effects thereof. Thesemeasures need to be mainstreamed into thedevelopment policy and practice so that it becomesnormal practice, fully institutionalized in the State.

The paper will attempt to present the actions to betaken by the state and various stakeholders namelyi) the owners of the buildings such the stategovernment, various undertakings, banks, businesses,housing boards, etc.: the various executingdepartments such as PWDs, DevelopmentAuthorities, health and education departments,cantonments, police and industries, etc. The LocalBody Authorities namely, the corporations, municipalcouncils, nagar panchayat and rural panchayats mustplay their regulating and monitoring roles. These


128 22 - 24 January, 2011

operations will requires capacity buildings at variouslevels in which the universities, technical andprofessional colleges and training centres will haveto play critical role. The funding organizations likebanks insurance etc. must develop techno-financialregulations so that all developments funded by theseorganizations are designed and constructed to remainsafe in the next earthquake.

Mainstreaming of disaster risk reduction will goa long way to minimize adverse impact of futureearthquakes in the State

Special - 7

S K Jain

CMD, NPCIL, Mumbai

Nuclear power in India is poised for a large expan-sion, based both on indigenous technologies and withforeign cooperation. In the next two decades, an in-stalled capacity of 63000 MW is planned to bereached from the present 4780 MW. This capacityis planned to be reached by setting up about 40,000MW of Light Water Reactors (LWR) in technicalcooperation with foreign countries and the remain-ing based on indigenous Pressurised Heavy WaterReactors (PHWR), Fast Breeder Reactors (FBR).The LWRs based on foreign cooperation are plannedto be indigenized progressively. There are also plansto develop and deploy indigenous LWRs

Safety is of paramount importance in nuclear power,the motto being safety first, generation next. Safetyagainst external natural events, particularly earth-quakes is accorded highest priority in nuclear powerplants, in siting, design, construction and operation.Structures, systems and equipment are designed andqualified for possible earthquake loads to ensure theirsafe and reliable performance during an earthquake.

Special - 8

Structure, Tectonics & Active Faults ofKutch Rift Basin, Gujarat, Western India

S. K. Biswas (Formerly: Director, KD MalviyaInstitute Petroleum Exploration, Dehradun FlatNo. 201, C-Block, ISM House Thakur village,Kandivili (E) Mumbai – 400 101 Ph: 022-28461593, 9820764910,E-mail: [email protected])

The Kutch basin is a western margin pericratonicrift basin of India. The rift is bound by Nagar Parkaruplift in the north and Kathiawar uplift (Saurashtrahorst) in the south respectively along Nagar Parkarand North Kathiawar faults (NPF & NKF). The riftis styled by three main uplifts along three masterfaults, (from north to south) Island Belt, KutchMainland and Wagad uplifts, with interveninggrabens and half-grabens. The uplifts are upthrustbasement blocks tilted along sub-vertical faults withinitial normal separation. The NKF is the principalmaster fault along which the rift subsided most. Thestructure is thus styled by tilted blocks and half-grabens within a south tilted asymmetric rift basin.Blanketing sediments over the basement drape overthe tilted edges of the upthrusts as marginal flexures.The flexures are narrow deformation zones alongmaster faults enclosing complicated folds, locallymuch faulted and intruded by igneous rocks. In thewestern part the uplifts are tilted to the south withflexures draped over the faulted up northern edges.In the eastern part a large uplift, Wagad Uplift,occurs between the Mainland and Island Belt uplifts.It is tilted opposite to the north with a narrowdeformation zone along the faulted southern edge.The backslope ends up against Bela horst of the IslandBelt uplift.

A subsurface basement ridge – Median High,crosses the basin at right angle to its axis in themiddle. Acting as a hinge it divides the basin into adeeper western part and a shallower and moretectonised eastern part. The rift is terminated in theeast against a transverse subsurface basement ridge,Radhanpur Arch, which is the western shoulder ofthe adjacent N-S oriented Cambay rift. To the westthe rift merges with offshore shelf.

The Kutch basin is the earliest pericratonic rift basinto form in the western margin of the Indian cratonduring the Late Triassic break up of Gondwanaland.The rift evolution with syn-rift sedimentationcontinued through Jurassic till Early Cretaceous asIndian plate separated from Africa and driftednorthward along an anticlockwise path. The riftexpanded from north to south by successivereactivation of primordial faults of Mid-Proterozoic

12922 - 24 January, 2011


Delhi fold belt. The faults strike E-W but eastwardthe strike swings to NE-SW merging with the Delhi-Aravalli strike.

The rifting was aborted by the trailing edge upliftduring Late Cretaceous pre-collision stage of theIndian plate. The uplift caused structural inversionduring rift-drift transition stage when most of theuplifts with drape folding over the edges came intoexistence by upthrusting along the master faults. Themotion during the drift stage of the plate inducedhorizontal stress and the near vertical normal faults,which were reactivated as reverse faults duringinitiation inversion cycle, became strike-slip faultsinvolving divergent oblique-slip movements.

The present structural style evolved by right lateralslip, which shifted the uplifts progressively eastwardrelative to each other from south to north. Thisresulted in the present en echelon positioning of theuplifts with respect to Kutch Mainland uplift. Thestrike slip related structuring modified the linearflexures breaking them into individual folds at therestraining and releasing bends. Narrow deformationzones complicated by conjugate reidal faults formedalong the master faults modifying the initial drapefolds. Syntectonic intrusions further modified thestructures.

Igneous rocks extensively intruded the Mesozoicsediments during rifting and post rift hotspot relatedDeccan volcanicity. Studies on the intrusive bodiesand seismological data suggest the presence of anultramafic magmatic body close to the crust-mantleboundary.

Inversion continues during post-collision compressiveregime of the Indian plate and the Kutch rift basinhas become a shear zone with transpressional strike-slip movements along the active sub-parallel riftfaults. This is evident from neotectonic movementsalong these faults that are responsible for the presentfirst order geomorphic features. In the currenttectonic cycle under NNE-SSW compressivestresses the KMF/ SWF and KHF are the mostactive faults as evident from the concentration ofaftershock hypocenters. Pulses of movement alongthese faults are responsible for generation of newfault fractures within the respective deformationzones. These new fractures are propagating throughthe recent piedmont and scarp-fan sediments in the

frontal zones of the thrusts as seen in the trenchesdug close to KMF and KHF and in GPR surveys.The pulses are also destabilizing the loose gravellysediments causing gravity sliding seen as low-angleto sub-horizontal fractures associated with the fault-generated fractures. The morphotectonic featuresalso indicate Quaternary uplift along the abovementioned faults.

During the present compressive stage the Radhanpurarch acts as a stress barrier for eastward movementsalong the principal deformation zones (PDZ). Thisis creating additional strain in this part of the basinbetween the arch and the Median High. The KutchMainland Fault (KMF) along the rift axis becomesthe active principal fault. Towards the eastern endof the Mainland uplift the right lateral KMF, becomesSouth Wagad Fault (SWF) by left stepping with anoverlap in the region between Samakhali andLakdiya. This overstep zone – Samakhiali-Lakadiyagraben - is a convergent transfer zone undergoingtranspressional stress in the strained eastern part ofthe basin. This is the most strained part of the basin.Expectedly, this is the most favoured site for rupturenucleation. The occurrence of closely spacedepicenters of two major earthquakes viz., 1956 Anjar(Ms 6.1) and 2001 Bhuj (Ms.7.9), in this zone andconcentration of aftershock hypocenters around itvalidate this conclusion.

The sub-vertical SWF is expected to flatten withdepth towards the south in the mid-crustal regionand merge with a listric link fault, presumably thenorthern rift margin fault, NPF. Thus, SWF isexpected to dip about 600 S in the mid crustal region.The similar pattern is indicated by the distribution ofthe aftershock hypocentres. The aftershock datasuggest a reverse slip on a fault plane dipping 60o

south as the causative fault. SWF zone, therefore,seems to be the causative fault of the Bhuj as wellas Anjar earthquakes. The curvature of the fault ata depth of 20+ km, close to the ultramafic magmaticbody at the base of the lower crust appears to bethe zone of earthquake nucleation. Presumably, thefluid released by the serpentinisation of the ultramaficbody aids the slippage along this causative fault.Based on this and the detailed depth wise analysisof aftershock data, a conceptual domino-listric modelof Kutch rift is presented here.


130 22 - 24 January, 2011

Special - 9

A TESTABLE MODEL FOR INTRAPLATEEARTHQUAKES

Pradeep Talwani ((Retired), Dept. of Earth andOcean Sciences, University of South Carolina,Columbia, SC, 29208, USA. E-mail:[email protected])

Globally, more than 98% of the total seismic momentrelease associated with intraplate earthquakes (IPE)occurs in former rifts and taphrogens (Schulte andMooney, 2001). The seismicity occurs at stressconcentrators in both shallow and deeper crust inresponse to the ambient compressional stress field(Gangopadhyay and Talwani, 2003). At manylocations of IPE, the stress field is further modifiedby local stress perturbations (e.g. due to glacialrebound, sedimentary deposition etc., Talwani andRajendran, 1990). Weakening agents, such as thepresence of fluids at hypocentral depths furtherinfluence the seismogenesis of IPE. Mooney andRitsema (2010) have shown that these rifted basinsare associated with a weaker lower crust, mappableby S-wave seismic tomography.

Modeling results have shown that when riftedsedimentary basins which had been formed underextension, with a priori weaknesses, are invertedunder compression, the results are weak conjugateand boundary faults with up-welled lower crust,identified as rift pillows These characteristic featuresof stress inversion are associated with local (~100ssq.km surface area) elevated strain rates. Theseobservations and modeling results suggest thefollowing testable model. Major IPE occur inreactivated rifted basins, with conjugate and boundaryfaults and an up-welled lower crust. (The precisegeometry and seismic potential of each site dependson its tectonic history and geometry after stressinversion). These features are sites of LOCAL stressconcentrations and elevated strain rates, and potentialIPE. I will illustrate these ideas with data from Kutchand Sea of Japan earthquakes.

To test this model and to predict potential locationsof IPE, S-wave tomography can be used to definethe weaker lower crust associated with rifted basins,and dense, continuous GPS observations can be usedto identify LOCAL pockets of elevated strain rates;

and seismicity and geophysical observations can beused to identify stress concentrators and locationsof IPE.

Special - 10

SPACE INPUTS IN DISASTERMONITORING, MITIGATION AND EARLYWARNING

R.R. Navalgund and A.S. Rajawat (SpaceApplications Centre, Indian Space ResearchOrganisation, Ahmedabad – 38 0015 INDIA Email:[email protected])

Natural disasters are events, which are caused bypurely natural phenomena and bring damage tohuman societies (such as earthquakes, volcaniceruptions, cyclones, spread of epidemics, asteroid/meteorite impacts etc.). Natural disasters areinevitable and in general difficult to predict. Human-induced disasters are natural disasters that areaccelerated/ aggravated by human influence (suchas landslides, forest fire, floods, land subsidence,desertification, coastal erosion etc.). Human madedisasters are events, which are caused by humanactivities (such as atmospheric pollution, industrial,chemical accidents, major armed conflicts, nuclearaccidents, oil spill etc.). Natural disasters may occurat global, regional or local scale. Time and spatialextent of disasters may vary e.g., earthquake maydestroy a large area in few seconds, landslide maydamage a small area in few minutes, floods maydamage a large area in few hours to days where asdrought may damage a large area in few weeks tomonths. Population growth and occupationrequirements force people to live in areas vulnerableto natural hazards, especially in developing and under-developed countries.

India has been traditionally vulnerable to naturalhazards on account of its unique geo-climaticsettings. It is frequently affected by disasters suchas tropical cyclones, floods, drought, earthquakes,landslides, forest fires, oil slicks and occasionallytsunami. Besides slow yet significant hazards likecoastal erosion, desertification, land degradation,glacial retreat and sea level rise are another threatour country faces.

Disaster management is the key issue and thecountry’s scientific and technological achievements

13122 - 24 January, 2011


have a major role to play in it. Disaster Managementaims to minimize loss of life, property andenvironment. Space provides scientific andtechnological ways and means in all stages ofDisaster Management. Disaster Managementinvolves effective Preparedness, Response,Rehabilitation, Reconstruction and Mitigation for aspecific disaster and improvement at each componentlevel with recurrence of that particular disaster.Communication satellites help in early warning andrelief mobilization. Earth observation satellites providereliable database for disaster prevention, mitigationand preparedness programmes. GeographicInformation System (GIS) provides additional toolto integrate large spatial and aspatial geo-referenceddata sets for improved disaster managementsolutions. A synergy of Earth Observation, GIS andcommunication technology is playing a major rolein effective disaster management.

Realizing the role of space technology in variouscomponents of a disaster management cycle,Department of Space, Indian Space ResearchOrganisation (ISRO) has launched DisasterManagement Support (DMS) Programme as one ofits key programs. Constellation of Indian satelliteSeries (IRS, Resourcesat, Cartosat, Oceansat,INSAT, GSAT) provides quick and reliable servicesin all phases of disaster management. The DMSprogram focuses on integrating the space technologyinputs and services, on a reliable and timely basisthrough various units of ISRO. Space based inputsare operationally provided to various state and centraluser agencies by Decision Support Centre of NationalRemote Sensing Centre (NRSC), Hyderabad forvarious natural disasters in particular for floods,drought and forest fire. Space Applications Centre,Ahmedabad provides R&D support to DMSProgramme by identifying and carrying out pilotstudies related to use of space technology for earlywarning of various natural disasters, developmentof Airborne DM-SAR and satellite based emergencycommunication systems. Indian Institute of RemoteSensing, Dehradun supports capacity building besidesR&D for various natural geo-hazards. Some of themajor disasters occurring frequently in India and useof space technology in disaster monitoring, mitigationand early warning are discussed in this paper.

The tropical cyclone constitutes one of the mostdestructive natural disasters over the coastal areas,which bear the brunt of the strong surface winds,squalls and flooding from storm rainfall and stormsurge as well as ocean wave action. The tropicalcyclone forecasting involves: Geolocation (Locatingthe position (centre) of the cyclone); Track changedetection; Intensity Estimation; Intensity changedetection. In all these aspects, satellites have beeneffectively used. Real-time cyclone track predictionalgorithms using INSAT data have been developed.All the cyclones in the Indian Ocean during 2005-2009 were tracked and predicted in real-time witha lead time of 48 h. Real-time track prediction fortropical cyclones GONU, SIDR, AKASH andNARGIS are some of the examples. 24 hour trackprediction error ranges from 36-136 km for differentalgorithms and 5-day track prediction error is < 250km. In addition, an Automated Intensity EstimationAlgorithm was developed using MultichannelMicrowave data, JTWC Intensity analysis(maximum sustained wind) and all global cyclonesfor the period 1998 – 2004. The accuracy ofdeveloped algorithm is ~11 kt, which is at par withthe accuracy of existing methods globally. As mostof the major cities are located near the coast, tidalfloods are serious disasters. Remote sensing dataespecially RADAR images are one of the powerfultools to map the inundated areas even when cloudsare present.

Satellite data is operationally analyzed for earlywarning of drought. Early warning of drought isbased on monitoring vegetation status using NationalOceanic and Atmospheric Administration (NOAA)Advanced Very High Resolution Radiometer(AVHRR) data for the entire country and IRS WiFS/AWiFS data for at district level. At present, fourteenStates of the country- Andhra Pradesh, Bihar,Chhatisgarh, Gujarat, Haryana, Jharkhand,Karnataka, Maharashtra, Madhya Pradesh,Maharashtra, Orissa, Rajasthan, Tamil Nadu,Uttarakhand and Uttar Pradesh are covered andbulletins giving the district-wise status are issuedfrom August to October. These bulletins are sent toDept. of Agriculture and cooperation, StateAgricultural Department and Relief Commissionerfor implementing relief measures.


132 22 - 24 January, 2011

Remote sensing is useful in identifying precursors toearthquakes such as sudden rise in land surfacetemperature, sudden changes in gravity anomaly andin assessing damage to infrastructures andgeomorphic changes caused by the earthquake innear real time. Early warning research throughidentification of precursors to earthquakes such assudden rise in land surface temperature (NOAAAVHRR data), have been carried out in hindcastmode for seismically active region of Kachchh,Gujarat. In addition, geophysical (gravity/magnetic)studies have been done in seismically active regionsof Kachchh and Andaman & Nicobar island regions.Differential SAR interferometry techniques arebeing explored for early detection of surfacedeformation of the crust (ALOS/ENVISAT/ERS-1/2 data) for seismically active zones such as partsof Kachchh, Gujarat and Himalayan regions.

Remote sensing and GIS techniques are used ininventory and monitoring of landslides and landslidehazard zonation. Methodology for Landslide hazardzonation has been developed by integratinginformation on lithology, structure, geomorphology,slope, aspect, land use/land cover, and drainage forsome of the most landslide prone regions of theHimalayan Ranges. Efforts are in progress towardsdeveloping rainfall threshold based early warningmodels of landslides in Garhwal and SikkimHimalayas.

Remote sensing data (IRS-1C/1D, MODIS, ASTERetc.) along with GIS techniques are being used toprovide information on Forest Fire detection andmonitoring; Post fire damage assessment, fire Scar/ burnt area mapping; Forest Fire prone / risk areamapping, and Planning the recovery of forest standand mitigation.

Remote sensing data helps in mapping desertificationprocesses/indicators and their severity.Desertification status mapping of entire country usingmultitemporal Resourcesat-1 AWiFS data on 1:500,000 scale has been carried out. Method for earlywarning of desertification was developed based onDesertification Vulnerability Index (DVI).

High and medium resolution and multi-temporalremote sensing data has proved useful for assessingthe damage caused by Tsunamis. Besides, this

tsunami warning system has become operational atINCOIS, Hyderabad using INSAT basedcommunication network among seismic stations, tidegauges, data buoys with pressure sensors. Coastalerosion has caused and continues to cause propertydamage, and large sums of money are spent tocontrol it. Shoreline change maps for the entire Indiancoastline have been prepared using remote sensingdata at 1: 50, 000 scale and at 1:25,000 scale.Vulnerable zones for coastal erosion have beenidentified. It is necessary to identify areas, whichmay be affected by sea level rise, so that remedialmeasures can be planned. An approach has beendeveloped to understand coastal processes usingIndian Remote Sensing Satellite data for carryingout Coastal Vulnerability Index (CVI) basedassessment of the coastal zone of Andhra Pradesh,Tamilnadu and Gujarat states.

Disaster is a global phenomenon. Any disaster thatstrikes does not restrict itself to a country’sadministrative boundary. Even if its effect is limitedto a particular country, it becomes a global concernfor response and relief. Hence, it is essential to havea network of various international organizationsworking towards disaster management, moreparticularly in the field of utilization of spacetechnology for disaster management. The activitiesof international organizations such as InternationalCharter on “Space and Major Disasters” GlobalEarth Observation System of Systems (GEOSS),UN-SPIDER, Sentinel Asia, GMES-SAFER,Disaster Monitoring Constellation etc. arenoteworthy. Efforts are in progress to realizeInternational cooperation to strengthen existingconstellation of EO satellites for specific applicationsrelated to all phases of disaster management and inparticular for early warning.

Special - 11

Bhuj 2001 Earthquake – Revisiting existingknowledge of structural behavior oftraditional and new constructions, geologicalhazards of the Kutch region and the regimeof seismic safety.

Alpa Sheth1 & V Thiruppugazh 2 (5 SeismicAdvisor, Gujarat State Disaster ManagementAuthority. Email: [email protected], 2

13322 - 24 January, 2011


Additional Chief Executive Officer, Gujarat StateDisaster Management Authority)

The Bhuj Earthquake of 2001 brought to the forefrontseveral knowledge gaps in our understanding of theseismicity of the region, expected behavior ofstructures in a region of such seismicity and theregime for ensuring structural safety of the builthabitat under seismic loads. The paper discussessome of these issues such as

Microzonation studies carried out in the Kutchregion identified hitherto unknown levels ofhazard. There is need to incorporate new-foundhazards in our design process throughupgradation of design codes.

Traditional housing which had some seismicresistant features behaved better than somereinforced concrete frame structures. The Bhujearthquake thus provided an occasion to reviewlong-held views that reinforced concretebuildings were safer than traditional homes andmade a case for confined masonry housing andother such systems.

The earthquake identified the need for havingindigenously grown mechanisms for seismicsafety. International regimes of regulatoryframeworks, implementation mechanisms andcode compliance do not work effectively for safehousing strategies in regions with a strong senseof tradition and a long history of disregard toformal processes. Innovative strategies involvingincentivization, sensitization and hand-holdingare more effective to foster a culture of seismicsafety than hard measures

Special - 12

The Road to Seismic Safety

Sudhir Jain, (Director IITgnr, Chandkheda,Ahmedabad, [email protected])

Special - 13

Bhuj earthquake and role of CEPTUniversity in post disaster scenario

Prof. V. R. Shah (H.O.D Structural Designdepartment, CEPT University, Ahmedabad, India

E-mail: [email protected])

Gujarat, India had a large magnitude earthquake in2001. CEPT University which is premier institute oflearning for the built environment in the region playeda major role for the post disaster work. Apart fromcarrying out a major rapid assessment survey of 5000houses for the city of Ahmedabad which was usedas model for other cities of Gujarat, the institute alsotook a lead role in post earthquake activities likereconstruction of villages and public buildings,conducting training programs for capacity buildingof architects, engineers and skilled workers. Toinvolve its students into these activities, the institutere-oriented its academic program for the semesterand the students got the first hand experience ofarchitectural design of reconstruction, planning ofvillages and towns and participation in capacitybuilding programmes, The presentation is on theactivities an institute carried out in the event ofdisaster like major earthquake.

The disaster like earthquakes are unfortunate eventsbut how even those can be converted into anopportunities for the students and professional forlearning and preparing them for the future was ablydemonstrated by an institute. Institute collected thedata of almost 5000 damaged houses which is nowa rare and huge data bank for study of various aspectsof behavior of modern urban structures.


134 22 - 24 January, 2011

AAcharyya Anshuman ........................................... 18,20

Adwani Akash ........................................................... 74

Aggarwal Sandeep ............... 6,14,46,75,76,77,78,89,107

Ahmad Bashir .......................................................... 115

Allameh-Zadeh Mostafa ............................................. 5

Alonso L. José .......................................................... 17

Anand S P ................................................................. 79

Ansari K ................................................................... 120

Arora B.R. .................................................... 30,44,60,85

Arora Yogesh ............................................................ 74

Ayra A S .................................................................... 127B

Bannerjee Chiranjib .................................................. 120

Bapat Arun ................................................................ 35

Barik Arijit ................................................................. 12

Baruah Saurabh ..................................................... 59,83

Bayasgalan Amgalan ............................................... 115

Bellalem F. .................................................................. 20

Berliet Ernelle ........................................................... 116

Bhakuni Chandra ...................................................... 54

Bhandari R. K. . ......................................................... 42

Bhanu Teja B ............................................................ 102

Bhatia Gagan ............................................................ 100

Bhatt N.Y. ..................................................................... 5

Bhattacharya F. ................................................... 93,120

Bhattacharya S.N. ............................................ 11,43,89Bhawal R.N ................................................. 103,104,105Bhawsar S.D ............................................... 103,104,105Bihari Om ................................................................... 89

Bilham Roger ........................................................ 26, 62

Bisht R S ................................................................... 112

Biswas Ankita ............................................................ 91

Biswas S. K. ................................................... 82,96, 128

Bobrovskii Alexander ................................................ 28

Bora K. Dipok ........................................................ 20,83

Bürgmann Roland ................................................ 91,92 C

Carcolé E. ................................................................... 83

Celebi E. ..................................................................... 72

Chadha R. K. ......................................................... 30,31

Chandan Bora. ........................................................... 20

Chandrashekar D.V. ........................................... 8, 91,92

AUTHOR INDEXChaudhuri H. ............................................................. 42

Chauhan Mukesh .................................................. 82,89

Chen C-H .................................................................. 31

Chhatre A.G. .......................................... 103,104,105,107

Choi1Jin-Hyuck ........................................................ 115

Chopra Sumer ................................ 56,58,61,75,76 ,87,95

Choubey V.M. ....................................................... 44,60

County Vestige Guzhen............................................ 119

Choudhary Suryanshu .............................................. 44

Choudhury Pallabee .............................................. 93,95D

Da-quan YAO ........................................................... 119

Das J. D. .................................................................... 91

Dasgupta Sujit ....................................................... 18,20Dastageer Faisal ......................................... 103,104,105Dattatrayam R.S. ................................................... 42,52

Devi Sunita ............................................................... 121

Dhiman Gunjan .......................................................... 51

Dikshit Onkar .................................................... 113,120

Dimri Siddhart ........................................................... 80

Dimri V.P. ............................................................ 108,123

Dumka R. K. ................................................. 29,82,93,95

Dutta Utpal ............................................................... 21

Dutta H.N. ................................................................. 33F

Fathian A. ................................................................. 118

Faticoni Barbara ...................................................... 116

Farooqui M. Yusuf ................................................... 121G

Gadhavi M S ............................................................. 120

Gahalaut Kalpna ........................................................ 22

Gahalaut V.K. .................................................... 22,91,95

Gamage Shantha S.N. ................................................ 11

Gaur M.S. ................................................................... 35

Gera B.S. .................................................................... 33

Gerstoft Peter ............................................................ 86

Ghatpande M.A. ........................................................ 35

Ghose D. .................................................................... 42

Giuliano F. Panza .............................................. 65,66,70

Goktepe F. .................................................................. 72

Gorshkov A. .............................................................. 66Goswami Rupen ....................................................... 103Gupta Sandeep ......................................................... 78

13522 - 24 January, 2011


Gupta A. K. ....................................................... 29,37,82

Gupta Harsh ........................................................ 23,122

Gupta Sushil .............................................................. 64

Gwal A.K. ................................................................... 44H

Hamdache M. ................................................... 21,59,68

Hao Xiao-Guang........................................................ 43

Hasan Syed Zaheer ................................................. 121

Hasegawa Koichi ...................................................... 64

Hassani B. ................................................................. 47

Hazarika Devajit ........................................................ 85

Hazarika Pinki ........................................................ 13,24

Helly Bruno ............................................................. 116

Hough Susan............................................................ 26

Hu Xiao-Gang............................................................ 43

Hwang Cheinway ...................................................... 33I

Ibrohim A. ................................................................. 118Ingole S.M .................................................. 103,104,105Irikura Kojiro .................................................... 58,61,63

Iyengar R N .............................................................. 126J

Jain D.K. ................................................................... 104Jain S K ..................................................................... 128

Jain Sudhir ................................................................ 133

Jagad Mehul .......................................................... 77,80

James Mr. Naveen ..................................................... 67

Jan M. Qasim ............................................................. 16

Jayangondapermal R. ................................................ 27

Jin Kwangmin ........................................................... 115

John Biju .................................................................. 114

Joshi Vishwa ....................................................... 89,107

Joshi A. ............................................................. 62,83,87

Joshi M. ..................................................................... 27

Juroyov R. ............................................................... 118K

Kamra Leena .............................................................. 44

Kaneko Fumio ....................................................... 47,64

Kato Teruyuki ............................................................ 92

Kayal J. R. ........................................................... 2,16,59

Kazmer Miklos ................................................... 121,117

Khan Prosanta K ....................................................... 11Khandwe Santosh ...................................... 103,104,105Kim Young-Seog ........................................ 121,115,119

Kolathayar Sreevalsa ................................................ 67

Korjenkov Andrey .................................................... 28

Kossobokov Vladimir G. ....................................... 3,4,64

Kothyari Ch.Girish ................................................ 29,82

Kouteva M ................................................................ 65

Kumar Abhishek ........................................................ 71

Kumar Deepak ........................................................... 51

Kumar Devender ....................................................... 28

Kumar Dinesh........................................ 17,61,18,87,106

Kumar M.Ravi ................................13,24,72,83,84,86,88

Kumar Narendra .......................................... 86,60,20,44

Kumar Naresh ................................................... 20,44,60

Kumar Praveen ...................................................... 69,84

Kumar Sushil ............................................... 34,80,81,64

Kumar Santosh ........................................ 6,106,14,46,57

Kumar Vikas ......................................................... 82,123

Kushwah Vinod Kumar ............................................ 35

Kuyuk H.S ................................................................. 72L

Lin S-J. ....................................................................... 31

López Casado C. ........................................................ 68

Lee M. ....................................................................... 119M

Madhusudana Rao K. ............................................... 88

Mahendar N. ............................................................. 98

Mahendar N. ............................................................. 98

Mahmood A.S. ......................................................... 115

Maibam Sarda ............................................................ 76

Majumdar T. J. ............................................. 92,93,94,95

Malaviya K. ............................................................... 18

Malhotra Dr. Praveen K. ............................................ 69

Malik Javed ......................................... 26,27,64,112,120

Malik Rupal .............................................................. 121

Mamyrov Ernes ......................................................... 28

Mandal Prantik ............................................ 2,3,6,16,21

Mandal H.S. ............................................................... 10

Manisha ..................................................................... 17

Matsuo Jun ........................................................... 47,64

Mehdi Waseem ........................................................ 33

Melana Deepanshu ................................................... 74

Mishra .O. P. ............................................................ 7,15Mishra Rajesh ................................................... 103,107Mittal Rahul ................................................ 103,104,105Mobarki M. ...................................................... 20,21,59


136 22 - 24 January, 2011

Mohan G. ................................................................... 23

Mohan Kapil ................................ 63,99,100,62,63,75,76

Mohanty S. ........................................................ 9,12,13

Mohanty William K. .................................. 20,50,70,110

Mohapatra Alok Kumar ......................................... 20,50

MonaLisa ................................................................... 16Mondal Apurba ........................................................ 104Mondal S.K. .............................................................. 32

Mori Jim .................................................................... 1,4

Morino M. ............................................................. 27,64

Morino Michio ...................................................... 27,64

Mr. Sunjay ................................................................ 100

Mukhopadhyay Basab ............................................. 20

Mualchin Lalliana ...................................................... 73

Mukhtar G.A. ........................................................... 115Murty C. V. R ............................................................ 102

NNagabhushanam P. ................................................ 41,28

Namita Pegu .............................................................. 72Navalgund R R ......................................................... 130Nawani P.C. .............................................................. 114

Naik Sambit P. .......................................................... 114

Nayak Shailesh ......................................................... 122

Nazari H. ................................................................... 118

Nekrasova Anastasia K. .......................................... 3,64

Negishi Hiroaki ............................................................ 4O

Olimat Waleed Eid .................................................... 69

Oveisi1 B. ................................................................. 118 P

P Anbazhagan ........................................................... 71

P Sasidhar ................................................................. 108

P. Mahesh .................................................................. 78

P. Pradeep .................................................................. 92

Pande Prabhas .......................................................... 1,9

Pandey .O.P. .............................................................. 74

Pandey Ajeet P. ..................................................... 74,40

Panza G.F ............................................................... 65,66

Parvez Imtiyaz ........................................................ 66,64

Paskaleva I ................................................................ 65

Patel Vandana ............................................................. 6

Patel girish ................................................................ 100

Patel H. S. ................................................................. 110

Patel V. M. ................................................................. 110

Patra .N. R. ................................................................ 114

Paul Ajay ................................................................... 93

Peláez J.A. ................................................................. 68

Peresan A. ............................................................. 64,66

Pérez.Omar J. ............................................................. 17

Petersen Mark ............................................................. 3

Pradhan Rashmi ............................................... 46,80,29

Prakasam K.S. ............................................................ 78

Prakash Rajesh .......................................................... 23

Prasad B. Rajendra .................................................... 96

Prasad M.S.B.S. ......................................................... 46Q

Qorashi M. ............................................................... 118R

R. Meena ................................................................... 32

Raghukant S T G ...................................................... 102

Rai S.S. ....................................................................... 18

Rajaram Mita ............................................................. 79

Rajaraman R. ............................................................. 108

Ramola R.C. .............................................................. 34

Rani Kavita .......................................................... 63,102

Rajawat A S .............................................................. 130

Rao .N. Purnachandra ............................. 13,23,24,25,72

Rao Ch. Nagabhushan .............................................. 25

Rao D. Gopala ............................................................ 98

Rao D.T. .................................................................... 114

Rao N. Purnachandra .............................. 13,23,24,25,72

Rastogi B. K. ............ 1,6,14,29,46,76,61,75,81,111,15,25

Rawat Vineeta ............................................................ 91

Ray Indrajit ............................................................... 104

Reddy C.D. ................................................................ 92

Reddy D.V. ............................................................. 28,41

Rehman Saifur ........................................................... 86

Rodkin M.V. ............................................................... 79

Rodríguez Carlos ....................................................... 17

Romanelli Fabio ......................................................... 66

Romashkova Leontina L. ............................................ 3

Roy K. S. ................................................................... 77

Roy P. N. S. ................................................................ 32

Roy Raghupati ......................................................... 104

Rust Derek ................................................................. 28S

S Rajesh ..................................................................... 94

Sahoo Santiswarup ................................................. 116

13722 - 24 January, 2011


Saikia D. ..................................................................... 84

Sairam B. ......................................................... 46,77,107Santosh B. .................................................. 103,104,105Saraf Arun K. ............................................................. 91

Sarkar Shivalika ......................................................... 44

Sarma Rajgopal ......................................................... 78

Sato Tamao ................................................................. 4

Satyanarayana H.V.S. ................................................ 23

Segawa Shukyo ......................................................... 47

Sen P. ......................................................................... 42

Shah A. A. ................................................................ 114

Shah R.D. ..................................................................... 5

Shah V R ................................................................... 133

Shandilya Anurag ..................................................... 45

Shaikh Md Babar ....................................................... 12

Sharma Babita ........................................................ 83,87

Sharma Kanika ........................................................... 91

Shashidhar D. ............................................................ 23

Shen Wen-Bin ........................................................... 41

Sheth Alpa ................................................................ 132

Shokri M. .................................................................. 118

Shukla A.K. ........................................................... 23,74Singh Anshuman ........................................ 103,104,105Singh Ramesh P. ....................................................... 33

Singh A. P. ........................................................ 15,75,76

Singh Anshuman ................................................... 18,20

Singh B ........................................................................ 8

Singh Arun ................................................................ 86

Singh R. K. ............................................................ 29,80

Singh Satish C. .......................................................... 58

Singh Savita .............................................................. 51Singh U.P .................................................... 103,104,105Singh Yogendra ........................................................ 114

Sinha B. ...................................................................... 42

Sinha Sushmita .......................................................... 13

Singhvi A. ............................................................ 26,120

Sitharam T.G. .......................................................... 48,67

Sivar K. ...................................................................... 18

Solanki P.M. ................................................................. 5

Solomon Raju P. ........................................................ 24

Sreejith K. M. ........................................................ 92,93

Srijayanthi G. .......................................................... 13,24

Srinagesh D. ..................................................... 13,23,24

Srivastava H N ..................................................... 43,74

Sukhtankar R. K. ........................................................ 92

Sumedha, ................................................................... 51

Sunil P.S. .................................................................... 92

Suraweera S.A.D.L.K. ............................................... 11

Suresh G. .................................................................... 42

Suresh N. ................................................................... 27

Surve,G. ...................................................................... 23

Sushini K ................................................................... 72

Suzat Yazdana............................................................ 91T

Talbi A. ................................................................... 20,21

Talwani Pradeep ................................................ 112,130

Teotia S.S. .................................................................. 18

Thiruppugazh V ........................................................ 87

Tiwari Arjun ............................................................... 14

Tripathi Jayant N. ........................................................ 4U

Umamaheswari A....................................................... 92

Ugalde A. ................................................................... 93V

Vaccari F. ............................................................... 66,70

Vaghmare Dr. Rajeev ................................................. 45

Vaideswaran Swapnamita C. ..................................... 93

Verma Akhilesh K. ............................................... 110,17Verma U.S.P……………………………………….101Vikrama Bhuvan....................................................... 113

Vipin Dr. K.S. ......................................................... 67,72W

Wadhawan Monika ................................................... 51

Walia Vivek ............................................................... 31

Wang Dijin ................................................................ 33

Wen K. L. ................................................................... 33

Wenzel Friedemann ................................................... 53

Winston S. Joseph ................................................... 108Y

Yadav Renu .............................................................. 51

Yang T. F. ................................................................... 31

Yadav Dilip Kr ........................................................... 20

Yi Jun ......................................................................... 41Z

Zafarani H. ................................................................. 47

Zuccolo E. ................................................................. 66

Zala Kishansinh .......................................................... 6

Documents

Bhuj2011-abstractvolume