Coseismic deformation and interseismic strain accumulation of the 2024 MS 7.1 Wushi earthquake in Xinjiang, China

Abstract

On January 23, 2024, a magnitude 7.1 earthquake occurred in Wushi County, Aksu Prefecture, Xinjiang, China. The epicenter was at the Maidan Fault, which is known for its left-lateral strike-slip and thrust properties in the Tianshan seismic zone. In this study, we used Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS) observations to investigate the characteristics and mechanisms of both the coseismic and interseismic deformation. The main findings are as follows: 1) The InSAR coseismic deformation displays clear thrust characteristics, with a maximum relative displacement of ∼0.8 m along the line of sight. This indicates a thrust-type earthquake. 2) The majority of the slip during the earthquake occurred within a 60 km × 40 km area, with depths ranging from 4 to 26 km. The maximum slip of the fault was about 2.3 m, corresponding to a moment magnitude of 7.0. 3) The seismogenic faults mainly exhibit thrust-type movement characteristics during the interseismic period and have a clearly defined locked state. The earthquake rupture depth aligns with the depth of locking during interseismic periods. 4) Before the earthquake, the seismogenic structure experienced compressive deformation in a north-south direction and the epicenter occurred at the edge of the high-strain area, as indicated by the GNSS strain rate.