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Geophysics Today Richard Allen *01, Karin Sigloch *08, Frederik Simons & Jeroen Tromp *92
Jeroen Tromp *92
Modern numerical methods and computers are transforming “forward” simulation capabilities
Daniel’s Coffee Cup Simulation
Open source software: SPECFEM3D “SESAME”
GPU CPU
GPU Computing
Princeton Earthquake Information"global.shakemovie.princeton.edu
Sumatra Earthquake April 11, 2012, M=8.7
resolution 17 s 5 h on 384 cores
Abundant, high-quality data are transforming “inversion” and “imaging” capabilities
“Adjoint” Tomography of Europe
earthquakes stations iterations simulations CPU hours measurements
190 745 30 17,100 2.3 million 123,205
Ebru Bozdag
Depth 75 km
Middle Hungarian line
Pannonian Basin
Massif Central
Central graben
Armorican Massif
Harz
Tornquist-Teisseyre Zone
Bohemian massif
Central Slovakian volcanic field
Eifel hotspot & Rhine graben
Alps slab
Cross sections
Eifel plume
Lithospheric delamination
Karin Sigloch *08
Seismic tomography: 3-D images of the mantle
Big challenge: the mantle in 4-D
Can the tomographic images be reconciled with plate reconstructions, land geology?
Waveform tomography using broadband data
Triplicated P waves from a mb 6.4 event, recorded by USArray. These are very strong signals (unlike receiver functions, underside reflections). They have rarely been used for tomography, since they require full waveform modelling.
S. S
tähl
er
Traveltime sensitivity kernels of P waves that are triplicated by the discontinuities of the mantle transition zone. Computations are done with the axisem code by Nissen-Meyer et al. 2007 (full 3D wavefields in a spherically layered earth, across the entire usable frequency range).
410 km
670 km
Waveform tomography using broadband data
Imaging a mantle plume under La Réunion
Imaging a mantle plume under La Réunion
Frederik Simons
Today’s geophysics is producing innovative
instrumentation
Bud Vincent
Text Text Text
Chris Harig
signal processing���
Kevin Lewis
Alain Plattner
Today’s geophysics is as engaging as it once was...
... but the undergraduates are just as tired as ever !
Richard Allen *01
Reaching Beyond the Ivory Tower: Reducing earthquake hazards ...while driving scientific discovery
As an example: Providing earthquake early warning …while learning about earthquake rupture
…and waveform propagation effects …and seismotectonics …and…
California’s earthquake problem
UCERF 2008 – USGS, CGS, SCEC
My office!
CISN California Integrated Seismic Network
Shake Alert
M3.5 Aromas Earthquake
…near the epicenter of
Loma Prieta
My desktop …on Friday
afternoon
ETH
Warning before an
earthquake
CISN California Integrated Seismic Network
Shake Alert
My desktop …on Friday
afternoon
ETH
M3.5 Aromas Earthquake
…near the epicenter of
Loma Prieta
Warning before an
earthquake
A public warning system…
Plans for:
• ~100 new seismic network stations
• Highrate realtime GPS stations
Dual use:
• Earthquake early warning
• All other research
…requires improved geophysical
networks
Dat
a: N
odal
Seis
mic
V
isua
lizat
ion:
Mag
ali B
arba
, Rob
Cla
yton
5km
7km
NodalSeismic Deployment
• Long Beach California
• 5000 geophones
• 6 months
…made data available!
river channel
highway
Dat
a: N
odal
Seis
mic
V
isua
lizat
ion:
Mag
ali B
arba
, Rob
Cla
yton
Smartphones? …the next generation of seismic network
California today: ~2000 seismic stations
~16 million smartphone accelerometers
…and around the world?
Smartphones • Accelerometers motion • GPS/wi-fi location • Magnetometer orientation • Built in communications
Big challenges…
the cloud
Realtime earthquake information
Waveform data for research
iShake Cal
Done.
Today’s geophysics is more than ever connected to
statistics
Sofia Olhede
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