| 2017-08-08四川九寨沟MS7.0地震对周边区域应力影响 |
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| 引用本文： | 董培育,乔学军,熊 维,柳 畅,石耀霖.2017-08-08四川九寨沟MS7.0地震对周边区域应力影响[J].大地测量与地球动力学,2018,38(12):1241-1245. |
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| 作者姓名： | 董培育 乔学军 熊 维 柳 畅 石耀霖 |
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| 摘 要： | 基于2017年九寨沟MS7.0地震破裂模型及区域均匀分层粘弹性地壳模型，计算此次地震引起的周边地区同震及震后库仑应力变化，讨论地震对周边若干活动断层的影响。结果表明，此次地震增加了虎牙断裂北段发震破裂区两端的库仑应力，最大同震库仑应力增量为148 kPa，在很大程度上超过地震应力触发阈值10 kPa，震后50 a内破裂区两端的库仑应力有所增强，但增量较小，仅在3~5 kPa左右；虎牙断裂南段同震库仑应力增量较小，在3 kPa左右，震后50 a内应力基本无变化；塔藏断裂带西北段的同震应力增量在5～33 kPa之间，在大部分区域超出应力触发阈值，震后应力有所加强，但是增量较小(约为3 kPa)。库仑应力加载有可能增加以上活动断层的地震危险性，需加强监测。地震对雪山断裂带西段(以虎牙断裂与雪山断裂交叉点为界)的影响较小，其同震库仑应力最大增量仅在6.15 kPa左右，未超过地震应力触发阈值。同时，地震还减小了雪山断裂带东段、白龙江断裂舟曲段、岷江断裂北部以及龙日坝断裂北部地区的库仑应力，可能短时间内减小了这些地区的地震危险性；而对距离震中较远(150 km以外)的地区(如青川断裂)影响十分微弱，其同震与震后应力变化可忽略不计。
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| 关 键 词： | 2017年九寨沟地震 库仑应力变化 地震活动性 |
Stress Influence on the Surrounding Area Induced by the 2017 MS7.0 Jiuzhaigou Earthquake |
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| DONG Peiyu,QIAO Xuejun,XIONG Wei,LIU Chang,SHI Yaolin.Stress Influence on the Surrounding Area Induced by the 2017 MS7.0 Jiuzhaigou Earthquake[J].Journal of Geodesy and Geodynamics,2018,38(12):1241-1245. |
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| Authors: | DONG Peiyu QIAO Xuejun XIONG Wei LIU Chang SHI Yaolin |
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| 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. |
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| Keywords: | Jiuzhaigou earthquake Coulomb failure stress change seismic activity |
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