Numerical simulation of dynamic Coulomb stress changes induced by M 6.5 earthquake in Wuding, Yunnan and its relationship with aftershocks

Based on the discrete wavenumber method, we calculate the fields of dynamic Coulomb rupture stress changes and static stress changes caused by M6.5 earthquake in Wuding, and study their relationship with the subsequent aftershocks. The results show that the spatial distribution patterns of the positive region of dynamic stress peak value and static stress peak value are similarly asymmetric, which are basically identical with distribution features of aftershock. The dynamic stress peak value and the static stress in the positive region are more than 0.1 MPa and 0.01 MPa of the triggering threshold, respectively, which indicates that the dynamic and static stresses are helpful for the occurrence of aftershock. This suggests that both influences of dynamic and static stresses should be considered other than only either of them when studying aftershock triggering in near field. Foundation item: National Natural Science Foundation of China (40364001) and Joint Seismological Science Foundation of China (605014).