Abstract: On 3 July 2015, an M_S6.5 earthquake occurred in Pishan County of Xinjiang, which caused huge local economic losses. We use interferometric synthetic aperture radar (InSAR) data from the European Space Agency’s Sentinel-1A satellite to invert the focal mechanism solutions of the event. First of all, two-pass interferometry technique is utilized to obtain the coseismic deformation of the region which covers the whole epicenter of the Pishan earthquake. Secondly, we utilize the uniform slip model in elastic half-space to derive the geometric and kinematic parameters of the seismogenic fault, and after that we use the distributed slip model inversion method to obtain a more precise distribution of fault slip by means of down-sampling the original observation data. The results indicate that the inversion results are consistent with the observation data. In addition, the inversion results show that the seismogenic fault is the blind fault, which is dominated by thrust movement with a very small amount of sinistral slip. The fault slip is concentrated mainly in the depth between 7 km and 15 km, the coseismic seismic moment is about 6.28×10¹⁸N·m (M_W6.46), which is consistent with the previous research.

Key words: Coseismic deformation, Slip distribution, Radar interferometry, The 2015 Pishan M_S6.5 earthquake