The Effect on the Nucleation and Failure of M_S7.0 Lushan Earthquake Induced by the M_S8.0 Wenchuan Earthquake

Abstract

Based on calculations of both the post-seismic Coulomb failure stress change and coseismic dynamic Coulomb failure stress change caused by the 2008 Wenchuan Ms8.0 earthquake, we simulate the their effects on the time of the nucleation and failure of the 2013 Lushan earthquake fault. Our calculation uses the rate-and state-dependent friction law and viscoelastic relaxation in the middle-lower crust and upper mantle. Furthermore, the triggering relationship between the Wenchuan and Lushan earthquakes is studied. The results show that the peak value of dynamic stress change on the Lushan earthquake fault induced by Wenchuan event is 0.127 MPa. With the 5-year accumulation of the viscoelastic relaxation in the middle-lower crust and upper mantle, the post-seismic stress change on the Lushan earthquake fault is 0.025 MPa. The results indicate that the process of the nucleation and failure of the Lushan earthquake fault is affected by the post-seismic Coulomb failure stress change, dynamic stress change and static stress change induced by the Wenchuan earthquake, and the effect of dynamic stress change is more obvious than others. Finally, we investigate the field of stress changes in the study area after the Lushan earthquake.