Abstract:By establishing the stress-driven post-seismic afterslip model, this paper numerically simulates the post-seismic afterslip effect of 2021 MW7.4 Maduo earthquake in Qinghai province. It then fits the GPS post-seismic deformation time-series data 160 days after the earthquake. The results show that afterslip is mainly distributed on the down-dip region and both sides of the coseismic rupture. The maximum slip is 1.24 m, and the cumulative released seismic moment is about 1.08×1019 Nm, which is equivalent to a MW6.62 earthquake. Afterslip at the depth of 5 to 15 km accounts for about 80% of the total afterslip. The optimal fitting model shows that the reference slip rate parameters V0 at the upper and lower regions of the fault are 6.5 m/a and 0.15 m/a, respectively, with the boundary depth of 13 km, which indicates that the difference of frictional properties at the Maduo earthquake afterslip interface is significant in the depth.