Abstract：Adopting the radar image of ascending and descending orbit provided by Sentinel-1A satellite, we study the coseismic deformation and focal mechanism of Menyuan earthquake. Firstly, based on D-InSAR technology, we obtain the coseismic deformation field of Menyuan earthquake. Then, taking the coseismic deformation field of ascending orbit and descending orbit as source data, we inverse fault parameters and slip distribution using the Okada uniform elastic semi-infinite dislocation model. Finally, the coseismic deformation field is forward modelled based on the coseismic sliding model. Experimental results show the maximum uplift deformations of ascending and descending coseismic deformation field along the radar line of sight are 39 cm and 58 cm, respectively. The maximum subsidence deformations of ascending and descending coseismic deformation field along the radar line of sight are all 56 cm. The earthquake is a left-handed strike-slip seismic event. The fault strikes along the NWW-SEE direction with the strike of 109° and dip of 86°. The maximum slip of 4.2 m, which is mainly concentrated in the underground 2 to 6 km. The released seismic distance of this earthquake is 8.22×1018 Nm(MW6.6). The forward results verify that the sliding distribution model is accurate and reliable.
YU Yi,LI Xue,SUN Zhen et al. Investigation on Focal Mechanism and Coseismic SlipDistribution for Menyuan Earthquake in 2022[J]. jgg, 2023, 43(1): 46-51.
