Ground Motions in Norcia, ItalyM 6.6 Earthquake on October 30, 2016M 6.2 Earthquake on August 24, 2016

Praveen K. MalhotraOctober 31, 2016

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Accelerations in Norcia M 6.6 @ 5.4 km October 30, 2016

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Accelerations in Norcia M 6.2 @ 14 km August 24, 2016

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Resultant Horizontal Accelerations in Norcia M 6.6 @ 5.4 km October 30, 2016

PGA = 0.526 g

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Resultant Horizontal Accelerations in Norcia M 6.2 @ 14 km August 24, 2016

PGA = 0.452 g

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Velocities in Norcia M 6.6 @ 5.4 km October 30, 2016

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Velocities in Norcia M 6.2 @ 14 km August 24, 2016

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Resultant Horizontal Velocities in NorciaM 6.6 @ 5.4 km October 30, 2016

PGV = 53 cm/s

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Resultant Horizontal Velocities in NorciaM 6.2 @ 14 km August 24, 2016

PGV = 30.2 cm/s

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Displacements in Norcia M 6.6 @ 5.4 kmOctober 30, 2016

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Displacements in Norcia M 6.2 @ 14 kmAugust 24, 2016

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Resultant Horizontal Displacements in Norcia M 6.6 @ 5.4 km October 30, 2016

PGD = 24.9 cm

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Resultant Horizontal Displacements in Norcia M 6.2 @ 14 km August 24, 2016

PGD = 8.19 cm

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Tripartite Response Spectrum of Horizontal Ground Motion in Norcia M 6.6 @ 5.4 km October 30, 2016

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Tripartite Response Spectrum of Horizontal Ground Motion in Norcia M 6.2 @ 14 km August 24, 2016

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Acceleration-Deformation Response Spectrum of Horizontal Ground Motion in Norcia M 6.6 @ 5.4 km October 30, 2016

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Acceleration-Deformation Response Spectrum of Horizontal Ground Motion in Norcia M 6.2 @ 14 km August 24, 2016

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Deformation Demands on Structures of Various Lateral Strengths in Norcia

Lateral Strength

(% of Weight)

Deformation Demands

M 6.2 August 24 M 6.6 October 30

50% 1.9 cm 27 cm

30% 6.8 cm 24 cm

25% 6.7 cm 21 cm

20% 17 cm 26 cm

10% 17 cm 26 cm

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Comments on Norcia Ground Motions• Deformation demands from the October 30th

earthquake are significantly higher than those from the August 24th earthquake

• It does not matter whether the October 30th

earthquake is called the mainshock or aftershock• What matters is that a structure experiences all

events (foreshocks, mainshock and aftershocks)• Dependent events (foreshocks and aftershocks)

are usually ignored in seismic hazard analysis• In seismic design, amplitudes and load cycles from

all dependent events should be considered

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Acknowledgment• Data may be obtained from Italian National

Strong Motion Network (RAN) managed by the Department of Civil Protection (DPC): http://ran.protezionecivile.it/IT/index.php

• Data processing is preliminary• No warranty of any kind is assumed