Coseismic Deformation and Slip Distribution of the 2022 Luding Mw 6.6 Earthquake Revealed by InSAR Observations

  Objectives  On 5th September 2022, an Mw 6.6 earthquake struck Luding and it is the largest earthquake on the Xianshuihe fault, Eastern Tibet in the past 40 years. It is of great significance for investigating the tectonic activity and assessing future seismic hazards in the region.

  Methods  In this study, we used Sentinel-1 and ALOS-2 synthetic aperture radar (SAR) images to retrieve coseismic surface displacements and then to determine the fault geometry parameters and slip distribution with a dislocation model in an elastic half-space.

  Results  The results show that the 2022 Luding Mw 6.6 earthquake is a left-lateral sliding event with a maximum surface displacement of 15 cm and 21 cm for the Sentinel-1 and ALOS-2 radar images, respectively. The fault ruptured along an NNW-SSE strike, and westward at a dip of 72°. The slip was concentrated at depths of 4-12 km with a maximum fault slip of 2.23 m occurring at a depth of 5.8 km.

  Conclusions  By analyzing the distribution of the coseismic landslides interpreted by optical images, we found that the coseismic landslides were mainly located on the west side of the fault, which is consistent with the aftershock distribution and can be considered due to hanging wall effects.