Revisiting the M7.3 1948 Ashgabat Earthquake Using Historic Seismograms and Satellite Imagery
The 1948 M 7.3 Ashgabat earthquake, killing over 38,000 people, occurred in the dextral strike-slip Kopeh Dagh fault zone in the Iran-Turkmenistan border region. Previously, it has been debated which fault(s) it occurred on and whether this earthquake was a thrust/reverse, strike-slip, or multi-fault earthquake, as published focal mechanisms suggest it had a reverse mechanism. We relocated the hypocentre using 24 historical seismograms and ISS phase arrival data. We present a new strike-slip focal mechanism from new first motion polarity and P/SH amplitude ratio data. We use Pleiades satellite stereo imagery to produce Digital Elevation Models of part of the ruptured area. These data reveal clear strike-slip faults where surface ruptures were mapped in 1948. The earthquake did not rupture the Main Kopeh Dagh fault, but instead these subsidiary faults, highlighting the importance of considering lesser faults in seismic hazard models.
Session: Everything Old Is New Again – Resurging Use of Analog Data [Poster]
Type: Poster
Room: Evergreen Ballroom
Date: 4/21/2022
Presentation Time: 08:00 AM Pacific
Presenting Author: Qi Ou
Student Presenter: Yes
Additional Authors
Neill Marshall Corresponding Author neill.marshall@earth.ox.ac.uk University of Oxford |
Qi Ou Presenting Author qi.ou@earth.ox.ac.uk University of Oxford |
Richard Walker richard.walker@earth.ox.ac.uk University of Oxford |
Christoph Grützner christoph.gruetzner@uni-jena.de Friedrich Schiller University Jena |
Eric Bergman bergman@seismo.com Global Seismological Services |
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Revisiting the M7.3 1948 Ashgabat Earthquake Using Historic Seismograms and Satellite Imagery
Category
Everything Old Is New Again – Resurging Use of Analog Data
Description