Measurement and Accuracy Evaluation of Surface Fault Displacements of the 2023 Southeastern Türkiye Earthquake Using Pixel Offset Analysis on Optical Satellite Images

Abstract

　With the recent increase in the number of optical satellites in operation, high resolution optical images are becoming increasingly available. In this study, we applied the pixel offset analysis on optical images acquired by PlanetScope, Sentinel-2 and Landsat satellites to measure the surface fault displacements associated with the 2023 southeastern Türkiye earthquake near the epicentral zone. The results from the analysis of PlanetScope images were the most accurate, although their north-south displacements contained striping noise, indicating that the image resolution is the principal factor of the accuracy. On the southwestern part in the analyzed area, the surface fault displacements obtained from the pixel offset analysis were systematically larger than the field-measured data, indicating finite thickness of the fault. On the northeastern part of the analyzed area, large surface fault displacements were obtained on a pre-matured segment, indicating that the strongly locked fault segment, on which large slip deficit had accumulated, ruptured to cause large displacements.