Slip Model of the 2022 Mw 6.6 Luding Earthquake from Inversion of GNSS and InSAR with Sentinel-1

Abstract

We use surface deformation measurements, including Interferometric Synthetic Aperture Radar data acquired by the Sentinel-1A satellites and Global Navigation Satellite System observations, to invert the fault geometry and coseismic slip distribution of the 2022 Mw 6.6 earthquake in Sichuan, China. The dip of the best-fitting model is 68°. The rupture of the 2022 Luding earthquake is dominated by northwest strike-slip movement, mainly concentrated over a length of about 20 km above a depth of 15 km. The maximum slip is at approximately 4 km depth with the maximum displacement of about 2.1 m. The results indicate that the 2022 Luding earthquake ruptured the shallow layer of the seismic zone. The slip distribution indicates that the Moxi–Shimian fault segment is fully locked from the surface down to 15 km, which is consistent with the estimated locking depth. Based on the Coulomb stress analysis and considering the strong locking state of the Anninghe fault, more attention should be paid to the possibility of earthquakes in the Anninghe fault.