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Group B, Poster #014, Seismology

Analysis of aftershock migration following the 2023 Türkiye-Syria earthquakes

Saeed Y. Mohanna, Max Liu, Lingsen Meng, Roland Bürgmann, & Tuncay Taymaz
Poster Image: 

Poster Presentation

2023 SCEC Annual Meeting, Poster #014, SCEC Contribution #12926 VIEW PDF
The 2023 Türkiye-Syria earthquakes occurred in a tectonically complex region on the East Anatolian Fault Zone. In the two weeks following the Mw7.8 mainshock, over 7000 aftershocks were detected by Anthony Lomax’s catalog (https://zenodo.org/record/7727678) that was produced using the nonlinear location spatially varying, source-specific station travel-time corrections (NLL-SSST-coherence) method. To get a complete picture of the aftershock activity, we use template matching to detect and GrowClust to relocate small (M<3) events recorded in 16 days of continuous data collected 3 days before and 13 days after the first mainshock. We detected 2.5 times more events in the same magnitude rang...e compared to the NLL-SSST-coherence catalog. An analysis of the location and spatiotemporal evolution of aftershocks in this updated catalog indicates that aseismic afterslip contributed to the aftershock migration on the north-eastern branch of the East Anatolian fault and the western branch of the Savrun-Çardak-Sürgü fault. We overlay an afterslip (log t) relation to a portion of the obtained spatiotemporal evolution on the latter branch and find an expansion rate of ~38 km/decade. The location of the afterslip onset coincides with the location of a creepmeter installed by Roger Bilham that recorded an accelerating creep signal of ~6 mm from early April to June 2023. Geodetic data will be analyzed to verify the contribution of afterslip and creep to aftershock production and rupture arrest. We will search for repeating earthquake sequences among aftershocks and earthquakes in the weeks leading up to the mainshock to examine the aseismic slip rate of this sequence.