Abstract：Based on Sentinel-1A ascending and descending image data, D-InSAR is used to obtain the coseismic deformation field in line of sight direction of the 2022-09-05 Luding earthquake. First, the Bayesian method is used to search the priori geometric parameters of the fault, and the non-negative least squares principle is used to invert the fine slip distribution of the fault, then the Coulomb stress variation in the area near the epicenter is calculated based on the parameters of the fault slip distribution, and finally the interseismic GPS velocity field data are used to calculate the interseismic strain field in the seismogenic region. The results show that: 1) The maximum deformation of the coseismic deformation field in line of sight direction of the Luding earthquake is 15 cm; 2) The Luding earthquake is a typical left-lateral strike-slip earthquake with a fault strike of NNW-SSE direction of about 167°, rupture along the strike direction is about 55 km, dip angle is about 74°, rupture depth is mainly 0-17 km, maximum slip is about 1.12 m, corresponding to a depth of 1 km, and release a total seismic moment 1.02×1019 Nm, corresponding to a moment magnitude of MW6.64; 3) The south-east section of the Xianshuihe fault zone, the north section of the Anninghe fault zone, and the middle-north section of the Yulongxi fault are in a stress-loaded state, and there is a greater possibility of future earthquakes; 4) The source area of the Luding earthquake is located in the transition region between tensile and extrusion strains, and this strain transition region may be related to the rendezvous of several different active blocks in the area.
WANG Xin,LI Shuiping,SONG Shunyue. Coseismic Slip Distribution and Coulomb Stress Variation of 2022 Luding MW6.6 Earthquake Based on InSAR Constraint[J]. jgg, 2023, 43(3): 226-231.
