Coseismic Rupture Behavior of the 2024 Nima (Tibet) MW 6.0 Earthquake Revealed by InSAR Observations

Objectives:On 1 June 2024, a shallow MW 6.0 earthquake struck the Nima County in the North-central Tibetan Plateau. As the largest earthquake to occur around the Laxiongcuo-gaerkong (LGF) fault zone, the occurrence of the 2024 Nima earthquake offers an important chance to further understand the distribution and kinetic characteristic of the seismogenic structures in this little studied region. Methods: In this paper, we use the ascending and descending SAR images of the Sentinel-1A satellite to acquire the coseismic surface deformation related to this event and investigate the seismogenic fault structure. Results and conclusions: Though both the NE-dipping and NW-dipping rupture fault models acquired by InSAR observations can fit the coseismic deformation well, we conclude that this earthquake nucleated a NE-dipping (a strike angle of 325°) right-lateral strike-slip fault with a dip of 83°, which may be a blind branch fault belonging to the LGF, according to the integrated analysis of the inversions, historical earthquakes, regional fault distributions and kinematics. In addition, coseismic coulomb stress changes reveal that the stress at the shallow part of the western segment of the middle branch fault of the XBF can reach 0.11 bar, indicating a high rupture risk.