Journal of Geophysics
Jiuzhaigou Earthquake; Wenchuan Earthquake; Post-earthquake Deformation; Finite Element Simulation; Coulomb Stress Change;
On August 8, 2017, an MS7.0 earthquake occurred in Jiuzhaigou, Sichuan Province, about 140 km away from the epicenter of the Wenchuan earthquake. The occurrence of the earthquake will adjust the regional stress distribution and influence regional seismicity changes. Then, how does the occurrence of the Wenchuan earthquake affect the Jiuzhaigou earthquake? How does the regional stress evolve? To answer these questions, this study is based on high-performance parallel finite element method and adaptive mesh refinement. By using the viscoelastic non-uniform ellipsoid earth model with topographic fluctuations, the spatiotemporal dynamic evolution of co-seismic and post-seismic stress induced by Wenchuan earthquake and its influence on the Jiuzhaigou earthquake are calculated respectively. Meanwhile, the effects of Wenchuan, Lushan and Jiuzhaigou earthquakes on the stress accumulation of surrounding faults are calculated considering the static stress of co-seismic and the adjustment of post-seismic viscoelastic stress. In addition, the occurrence of Wenchuan, Lushan and Jiuzhaigou earthquakes may lead to the southern segment of Longmenshan fault to Yingxiu, the eastern segment of Dongkunlun fault, the eastern segment of Longriba fault, the northern segment of Minjiang fault and Kangding of Xianshuihe fault. Segment stress loading is greater than 0.01 MPa, which increases the risk of earthquakes in these fault zones.