The 2020 Sivrice Earthquake (MW6.8) and Its Seismotectonic Linkage to the 2023 Kahramanmaraş Earthquakes (MW7.8 and 7.6)

Abstract

A series of earthquakes along the East Anatolian Fault Zone (EAFZ) started with the January 24, 2020, Sivrice (Elazığ) Earthquake (MW6.8) and culminated in the the catastrophic Kahramanmaraş Earthquakes (MW7.8 and MW7.6) on February 6, 2023. This study explores how the 2020 Sivrice event influenced the 2023 Kahramanmaraş earthquakes using field surveys and seismotectonic analyses.The 2020 earthquake, occurring in the northeastern part of Pütürge Segment, was followed by field surveys and Differential interferometry (DInSAR) analysis to determine fault geometry and slip distribution. Seismological studies, including moment tensor solutions, stress tensor analysis, and Coulomb stress changes, provided insights into the fault dynamics. Surface deformations were observed in a 50 km section of the Pütürge segment, showing R, R', T, P, and Y fractures typical of a left-lateral deformation zone. The moment tensor analysis revealed a left-lateral strike-slip fault trending N65 degrees E, with a minor normal component. The timing and location of the earthquakes, suggest that the rupture progresses bilaterally. The analysis of Coulomb stress changes showed that the 2020 event transferred stress to the Arıkonak sub-segment, the Yarpuzlu restraining double-bend, the Erkenek Segment of the EAFZ, as well as the Gerger and Narince Segments of the Southeastern Anatolian Thrust Zone. These areas were further stressed by the 2020 earthquake, setting the stage for the February 2023 Kahramanmaraş events. Thus, the 2020 Sivrice earthquake served as a trigger for the catastrophic 2023 earthquakes. The Arıkonak sub-segment, Gerger, and Narince segments are still potential sources of earthquake hazard.