Preliminary results of the great Kahramanmaraş 6 February 2023 Earthquakes (MW 7.7and 7.6) and 20 February 2023 Antakya Earthquake (MW 6.4), Eastern Türkiye

Abstract

The first MW 7.7 and second MW 7.6 Kahramanmaraş earthquakes were the strongest tectonic events in Eastern Türkiye since the MW 7.9 Erzincan earthquake in 1939. The first and second events occurred on the Pazarcık and Çardak segments of the East Anatolian Fault System, respectively. A subsequent significant earthquake of MW 6.4 occurred in the Antakya fault zone. We summarize preliminary earthquake data and share our previous field observations to better understand the mechanism and provide scientific consequences for future investigations and layout planning. After combining the field observations, kinematic analysis of fault surfaces, investigations of orthophotos, characteristics of mainshocks, and differential interferometry analysis of Sentinel-1A synthetic aperture radar images are used to evaluate the surface deformation from an earth sciences point of view. As a result, field data, paleostress analysis, and deformation zones are found to be completely consistent with the focal mechanism solutions of recent earthquakes. Furthermore, the first MW 7.7 event would have been caused by motion along the Pazarcık and Amanos segments at the same time as a single seismic segment.