Publication Date:
2023-08-09
Description:
An earthquake sequence occurred along the East Anatolian fault (EAF, Mw 7.8) and Sürgü fault (SF, Mw 7.6) in the Kahramanmaras region (Southern Turkey). Both earthquakes show strike-slip mechanisms and shallow hypocentre (〈15 km), with NE-SW trending Kahramanmaras and Karasu fault segments reaching ~300 km and E-W trending 150 km Sürgü fault length, respectively. An analogue seismic event according to historical catalogue is the 29 November 1114 that severely affected Antachia, Marash and Urfa with about 40 000 victims. Christian and Muslim chroniclers report the occurrence of two large seismic events, a comparable situation to the 2023 events. Field investigations conducted in 2005 in the frame of the EC-Funded APAME project show ~4 m to ~80 m left-lateral offset streams along the fault zone south of Kahramanmaras city. InSAR results from Sentinel images provide an accurate mapping of the Kahramanmaras and Karasu fault traces with estimated ~3 m to ~8 m left-lateral slip along strike. Repeated GPS measurements from 1991 – 2004 allow us to determine horizontal velocities of 22 stations located across the EAF in southern Turkey. By using a simple locked fault model, we estimate that the relative left-lateral plate motion across the EAF is 9.7 ± 0.9 mm/yr., and 4.4 ± 0.4 mm/yr across the Karasu fault. The ~900 year of interseismic relative quiescence and 9.7 mm/yr left-lateral block velocity, surface faulting geomorphology and paleoseismic results along the EAF may explain the occurrence of the Mw 7.8 event.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
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