Fifteen-year evolution of the crustal total shear strain in a reference to the recent East Anatolian earthquakes
1 Geophysical Center RAS, Moscow, Russia
2 Hacettepe University, Ankara, Turkey
3 People's Friendship University of Russia, Moscow, Russia
4 Yuzuncu Yil University, Van, Turkey
5 Kocaeli University, Izmit, Turkey
Abstract
The study analyzes the accumulated horizontal total shear strains in Eastern Anatolia due to the region’s largest earthquakes in&enbsp;2010, 2020, and 2023. The study used the results of continuous daily measurements of the GNSS network TUSAGA-Aktif (Turkey) [Kurt et al., 2020] over an interval of more than 13 years. Synoptic analysis of deformation allowed us to see the following features.
Before the first earthquake Elazig M6.1 (2010), significant shear deformations >2.5×10-7 accumulated in the future epicenter for 15 months. After its implementation, they weakened slightly, contributing to the short-term "locking" of the gaps.
Over the next 10 years, the shifts intensified and spread to the site of the future event M6.7 (2020), as well as to the area of future catastrophic earthquakes M7.5–7.8 (2023).
The strong Elazig-Malatya earthquake of 2020 developed the strike-slip region and moved it towards the zone of future strong earthquakes in 2023.
Before the strongest events, a "flow" of total shear deformation >7.5×10-7 advanced into the region of the first of them. This evolution confirms the existence of a deformation wave — a trigger for strong events [Kaftan, Melnikov, 2019; Kaftan, Tatarinov, 2022].
The catastrophic events of February 2023 created a maximum shift in the area of their own epicenters, but also in the area of the first Elazig event, hundreds of kilometers away. Here, six months after the second Elazig-Malatya event, a pair of moderate Bingöl earthquakes M5.5–5.9 occurred, probably contributing to the development of shear deformations here. At the same time, the existence of a minimum total shift at the Elazig-Malatya epicenter M6.7 is surprising. This place turned out to be more locked than the northern part of the East Anatolian Fault.
The propagation of total shear deformation from the beginning of their accumulation to the epicenters of future quasi-megaquakes demonstrates its triggering effect on a mature seismic source.
Database creation date: November 2023; Publication date: November 2023
Contributor:
Geophysical Center of the Russian Academy of Sciences, Moscow, Russia
Institution: Geophysical Center of the Russian Academy of Sciences, Moscow, Russia
Publisher: Geophysical Center of the Russian Academy of Sciences (GC RAS), Moscow, Russia (http://www.gcras.ru/eng/)
Data format: .mov (QuickTime File Format)
Citation: Kaftan V. I., M. A. Guvenaltin, P. A. Dokukin, M. Toker, T. S. Irmak (2023) Fifteen-year evolution of the crustal total shear strain in a reference to the recent East Anatolian earthquakes. ESDB repository, GCRAS, Moscow, https://doi.org/10.2205/ESDB-000877-d02
References:
Kaftan V.I., Tatarinov V.N. Registration of Slow Deformation Waves According to GNSS Observations. // Doklady Earth Sciences, 2022. Vol. 505, Part 1. P. 489–495. DOI: 10.1134/S1028334X22070091
Kurt A.İ., Cingöz A., Özdemir S., Peker S., Özel Ö. ve Simav M. Türkiye Ulusal Temel GNSS Ağı (TUTGA) Güncel Koordinat ve Hızlarının GNSS Verilerinin Yeniden Değerlendirilmesi Kapsamında Hesaplanması. // Harita Dergisi. 2020. Vol. 164. P. 1–17
License: 
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
URL for downloading: http://esdb.wdcb.ru/doi/2023/ESDB-000877/ESDB-000877-d02.mov
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