摘要

Twelve Sentinel-1 images are used to measure the surface displacements caused by the Zaduo earthquake on 17 October 2016 in Qinghai, China. Comprehensive analysis of the local geologic structure, focal mechanisms, relocated aftershocks, and fault geometrical parameters from nonlinear inversions of the InSAR data indicates that a NE-trending fault with a strike of61 degrees, namely the Aduo fault, was responsible for this event. Further geodetic inversions for finite fault models show that the dip angle of this fault is 75 degrees to the SE. The majority of the slip occurred at the depth from 5km to 17km, and the normal-slip component was comparable to the strike-slip component. The peak slip of31cm occurred at a depth of10km. The InSAR determined moment is 9.61x10(17) Nm with a rigidity of 30 GPa, equivalent to Mw 5.9. The geological map reveals that the Aduo fault was characterized by a left-lateral strike-slip component in the past, as evidenced by the offset of Paleogene sedimentary rocks. Our results for the Zaduo earthquake suggest that the Qiangtang block probably consists of two or more sub-blocks with different eastward extrusion velocities and that the deformation of the Qiangtang block is occurring not only along its boundaries but also in its interior.