06 Şubat 2023, Pazarcık (Kahramanmaraş, Türkiye) depreminin neden olduğu jeomorfolojik deformasyon örnekleri

Abstract

The left-laterally strike-slip Pazarcık fault is one of the East Anatolian Fault Zone (EAFZ) segments. On February 6, 2023, the ±85 km long Pazarcık fault generated a highly destructive Mw=7.7 earthquake. This study aims to explain the geomorphological deformations caused by the February 6, 2023, Pazarcık earthquake with typical examples. The surface rupture of the earthquake between Türkoğlu and Gölbaşı was followed precisely, and the changes in the earth's surface due to the left lateral strike-slip were determined, measured, and recorded. A DJI Phantom 4 and a DJI Mini Drone were used for aerial measurements and recordings during the fieldwork. Garmin e-Trex 10 handheld GPS and tape measure were used for terrestrial measurements. During the field studies, the surface rupture of the earthquake was investigated from a geomorphological perspective and mapped by taking location data. It was determined by the measurements that the left lateral offset distances in the surface fracture vary between 4.0-6.5m. One of the geomorphological deformations of the February 6, 2023 earthquake is transpressional ridges and/or transtensional depressions. Transpressional shortening and/or transtensional extension deformations due to a single surface rupture are the natural consequences of the curvilinear slip plane of the left-laterally strike-slip Pazarcık fault. Liquefaction samples with different characteristics were observed in the Sakarkaya alluvial fill area within the Gölbaşı depression. Rockfalls occurred on sandstone, mudstone, and limestone rock slopes weakened by the discontinuity due to the density of cracks outcropping in the valley where the surface rupture passes in the Kartal, Sakarkaya section. During field studies, slides and spreading were also observed. Typical examples of slide occurred on the unconsolidated fill ground on the south coast of Gölbaşı Lake with a slight slope towards the lake as a result of the vibration effect of the earthquake. In addition, the vibration effect of the earthquake caused lateral spreading deformations in the artificial fillings of road and road junction structures.