Finite Element Method to invert coseismic slip of Yutian Earthquake from InSAR

摘要

The 2009 Ms 7.3 Yutian Earthquake ruptured the boundary between Yutian Country and Qira Country, Xinjiang. To simulate coseismic deformation of an earthquake, usually dislocation model with the assumption of homogeneous, isotropic and elastic half-space are applied. However, these assumptions are oversimplified and not always able to precisely approximate every earthquake. Here we took Finite Element Method (FEM) instead of dislocation model to infer coseismic fault slip from surface deformation observed by InSAR. To obtain Yutian earthquake coseismic displacement, ENVISAR/ASAR data from both descending and ascending orbits were processed. AQAQUS code was taken to generate Green functions and Quadratic Programming algorithm was implemented in the linear inversion. The inversed slip distribution imply Yutian earthquake to be a simple event with only one slip concentration on the fault plane. Maximum slip is up to 3.89m near the surface, occurs at N35.370, E81.510. The estimated moment magnitude is Mw7.1.