Abstract：Based on the slip model of the 2017 MS7.0 Jiuzhaigou earthquake and the uniform viscoelastic semi-infinite space model, we examine the co-seismic and post-seismic Coulomb failure stress change (ΔCFS) induced by this earthquake and investigate its influence on the surrounding area. We find that the co-seismic ΔCFS increased by 148 kPa at both ends of the rupture zone of the north segment of Huya fault, which is over the stress threshold (10 kPa). In the next 50 years, the ΔCFS continues to increase, but the value is only between 3~5 kPa. The co-seismic ΔCFS increases only 0~3 kPa on the south part of the Huya fault, and the post-seismic shows roughly no changes. The northwest part of Tazang fault has a 5~33 kPa co-seismic ΔCFS increase, which is also over the threshold, and continues to be enhanced in the next 50 years. The ΔCFS on the west part of Xueshan fault is promoted by 6.15 kPa, which is less than the threshold, caused by the co-seismic, but shows little influence in the future. All these segments of the faults, with ΔCFS increases over 10 kPa, signal the raising earthquake activity, and the need for enhanced monitoring. Respectively, this earthquake released the stress on the eastern part of Xueshan fault, the Zhouqu segment of Bailongjiang fault, the northern part of Minjiang fault and the north part of Longriba fault. The seismic activity of these regions may decrease within a short time. The Qingchuan fault, which is far away from the epicenter, and other remote areas, are weakly influenced; co-seismic and post-seismic stress changes are negligible.
DONG Peiyu,QIAO Xuejun,XIONG Wei et al. Stress Influence on the Surrounding Area Induced by the 2017 MS7.0 Jiuzhaigou Earthquake[J]. jgg, 2018, 38(12): 1241-1245.
