Objectives On January 7, 2025, an Ms 6.8 earthquake struck Dingri County, Shigatse City, Xizang Autonomous Region,China, resulting in numerous casualties. This earthquake took place within the Lhasa block of the Qinghai-Tibet Plateau. To swiftly ascertain the seismogenic structure of this earthquake and gain a precise understanding of its source mechanism, this study utilized ascending data from the Lutan-1 (LT-1) satellite and descending data from the Sentinel-1 satellite to extract surface coseismic deformation.
Methods This deformation data served as constraint information for the inversion of geometric parameters and slip distribution of the seismogenic fault.
Results The findings reveal that the earthquake-affected areas primarily exhibited near east-west extension deformation, with the maximum deformation in the line of sight direction attaining 2 m. The inversion outcomes demonstrate that the earthquake occurred on a normal fault with a strike of 187° and a dip angle of 40°, exhibiting a maximum slip of 6 m and a simulated moment magnitude of 7.1. By simulating earthquake intensity based on the estimated fault slip model, it was found that the maximum intensity of this earthquake could reach level Ⅸ.
Conclusions The integrated application of interferometry synthetic aperture radar seismic coseismic deformation field and a two-step fault parameter inversion algorithm achieved a rapid acquisition of the earthquake's source mechanism and rupture parameters. This approach offers swift and precise data support for earthquake emergency response, intensity estimation, and damage analysis.
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