Impact of complete Coulomb failure stress changes of the 2008 Xinjiang Yutian M_S7.3 earthquake on the subsequent earthquakes

Based on the discrete-wavenumber method, we calculated the complete Coulomb failure stress (CFS) changes of near-field region induced by 21 March 2008, Yutian, Xinjiang, M_S7.3 earthquake, and analyzed their impact on the aftershocks. We also get the dynamic CFS changes of the Yutian earthquake produced at the epicentral location of the Wuqia M_S6.8 earthquake on 5 October 2008. The calculated results show that the evolution of CFS change patterns lasted for almost 60 s, and trigger ratio of aftershocks by the main shock is above 90%. Dynamic CFS change patterns can better explain the distribution of aftershocks. Complete CFS changes results of aftershocks indicate that the dynamic CFS changes are far greater than static ones. The maximum dynamic CFS change at the epicenter of Wuqia earthquake is 0.12 MPa, suggesting that the Wuqia event may be triggered by dynamic Coulomb stresses induced by the Yutian event, but the triggering effect is unremarkable and static CFS changes have little influence on it.