Séisme à Achgabat au Turkménistan 1948

[Naos46]

Bonjour à tous

Quelqu’un sait qu’il connaît-il la cause du séisme à Achgabat au Turkménistan en 1948 ?

Subduction ? Faille décochante ? Intraplaque ?

Merci
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[Tawahi-Kiwi]

Marshall, Walker, Qi & Gruetzner, 2022 - A re-evaluation of the 5th October 1948 M7.3 Ashgabat earthquake (Turkmenistan)

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 historical seismograms and present a new strike-slip focal mechanism. We used 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.

Source: Walker et al., 2021

En gros, un seisme dans la fold-and-thrust belt de l'Iran, qui est la limite entre la plaque de Turan (qui fait partie de l'Eurasie) et la zone de collision.
La faille transformante de Kopeh Dagh semble etre l'extension orientale du Caucase.

T-K