Ground Motion Records fromM 7.8 Ecuador Earthquake of

April 16, 2016

Praveen K. MalhotraJune 22, 2016

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Acknowledgment• Data processing is preliminary. No warranty of any

kind is assumed• Data may be downloaded from Instituto Geofísico

website: http://www.igepn.edu.ec/servicios/eq20160416

• Data may be viewed at CESMD Virtual Data Center website: http://strongmotioncenter.org/vdc/scripts/event.plx?evt=1317

• Dr. Erol Kalkan of USGS helped access the data

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Recording Stations Relative to Epicenter

Epicenter

AES2

APED

AMNT

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USGS Shake Map and Rupture Area

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Accelerations at APED Station in Pedernales (36 km from Epicenter)East

Up

North

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Resultant Horizontal Accelerations at APED Station in Pedernales

PGA = 1.42 g

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Velocities at APED Station in Pedernales (36 km from Epicenter)East

Up

North

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Resultant Horizontal Velocities at APED Station in Pedernales

PGV = 85.6 cm/s

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Displacements at APED Station in Pedernales (36 km from Epicenter)East

Up

North

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Resultant Horizontal Displacements atAPED Station in Pedernales

PGD = 25.2 cm

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5% Damping Response Spectrum of Horizontal Motion at APED Station in Pedernales

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Acceleration-Deformation Response Spectrum of Horizontal Motion at APED Station in Pedernales

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Accelerations at AES2 Station in Esmeraldas (76 km from Epicenter)

East

Up

North

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Resultant Horizontal Accelerations at AES2 Station in Esmeraldas

PGA = 0.155 g

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Velocities at AES2 Station in Esmeraldas(76 km from Epicenter)

East

Up

North

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Resultant Horizontal Velocities at AES2 Station in Esmeraldas

PGV = 35.1 cm/s

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Displacements at AES2 Station in Esmeraldas (76 km from Epicenter)

East

Up

North

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Resultant Horizontal Displacements atAES2 Station in Esmeraldas

PGD = 17.8 cm

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5% Damping Response Spectrum of Horizontal Motion at AES2 Station in Esmeraldas

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Acceleration-Deformation Response Spectrum of Horizontal Motion at AES2 Station in Esmeraldas

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Accelerations at AMNT Station in Manta(171 km from Epicenter)

East

Up

North

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Resultant Horizontal Accelerations at AMNT Station in Manta

PGA = 0.547 g

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Velocities at AMNT Station in Manta(171 km from Epicenter)

East

Up

North

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Resultant Horizontal Velocities at AMNT Station in Manta

PGV = 55.4 cm/s

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Displacements at AMNT Station in Manta(171 km from Epicenter)

East

Up

North

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Resultant Horizontal Displacements atAMNT Station in Manta

PGD = 29.2 cm

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5% Damping Response Spectrum of Horizontal Motion at AMNT Station in Manta

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Acceleration-Deformation Spectrum of Horizontal Motion at AMNT Station in Manta

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Observations• Ground motions are medium-band• Estimated ground displacements are

somewhat smaller than expected• Strong shaking at AMNT station at 171 km

from epicenter is probably due to its close proximity to the rupture area (Slide 4)

• Unusually long duration at AES2 station is probably due to low-frequency ground shaking at that location. The number of cycles is not unusual