2017年九寨沟MS7.0地震对附近断层的影响分析

doi:10.12196/j.issn.1000-3274.2020.01.009

摘要/Abstract

摘要： 2017年8月8日四川省九寨沟发生M_S7.0地震, 引起了专家们对其附近地区未来强震危险性的关注。根据弹性半空间位错理论, 利用通过远场地震波形资料和InSAR资料联合反演得到的2017年九寨沟M_S7.0地震震源断层面上的位错分布, 计算了九寨沟M_S7.0地震在附近断裂带上产生的剪切应力、正应力和库仑破裂应力。不同深度的水平面上剪切应力、正应力和库仑破裂应力的分布显示, 2017年九寨沟M_S7.0地震对其震中附近的塔藏断裂、岷江断裂北段、东门沟断裂和虎牙断裂北段等的影响明显, 对其他断裂带的影响不甚明显。随着深度的增加, 影响似有减弱的趋势。本文还给出了剪切应力、正应力和库仑破裂应力在塔藏断裂、岷江断裂北段、东门沟断裂和虎牙断裂北段断层面上的分布, 计算了断层面上不同深度区域内剪切应力、正应力和库仑破裂应力平均值。据此分析表明, 2017年九寨沟M_S7.0地震可能使塔藏断裂、东门沟断裂、岷江断裂北段发震时间推迟, 使虎牙断裂带北段断层面变得容易错动, 其发震的危险性可能会增加。

关键词: 2017年九寨沟M_S7.0地震, 库仑破裂应力, 发震危险性

Abstract: On August 8, 2017, a magnitude M_S7.0 earthquake struck at Jiuzhaigou, Sichuan province, China. Seismic risk of other nearby faults has attracted attention of seismologists. In this study, according to the elastic dislocation model for focal faults in a half elastic space, we calculated the accessional shear stress, normal stress and Coulomb stress imparted on other nearby faults by the 2017 Jiuzhaigou M_S7.0 earthquake. In calculation, data of dislocation distribution, obtained with the inversion technique using the teleseismic wave form and InSAR data, on the focal fault plane of the Jiuzhaigou M_S7.0 earthquake is used. We imaged the distribution of the accessional shear stress, normal stress and Coulomb stress on the horizontal plane with different depths along target faults. The stronger impact can be found on Tazang fault, north segment of Minjiang fault, Dongmengou fault and north segment of Huya fault. We also imaged the distribution of the accessional shear stress, normal stress and Coulomb stress on these four target fault planes, and calculated the average value of stresses within ranges of different depths. The results obtained show that the Jiuzhaigou M_S7.0 earthquake could inhibit the rupture of Tazang fault, Dongmengou fault and north segment of Minjiang fault, and promote the rupture of north segment of Huya fault.

Key words: the Jiuzhaigou M_S7.0 earthquake, seismic risk, the Coulomb stress

中图分类号:

P315.7

李艳娥, 邢成起, 陈学忠. 2017年九寨沟M_S7.0地震对附近断层的影响分析[J]. 地震, 2020, 40(1): 112-127.

LI Yan-e, XING Cheng-qi, CHEN Xue-zhong. The Effect of the 2017 Jiuzhaigou M_S7.0 Earthquake on the Seismic Risk of Other Nearby Faults[J]. EARTHQUAKE, 2020, 40(1): 112-127.

参考文献

[1] Stein R S, King G C P, Lin J. Change in failure stress on the southern San Andreas fault system caused by the 1992 mangitude=7.4 Landers earthquake[J]. Science, 1992, 258(5086): 1328-1332.
[2] King G C P, Stein R S, Lin J. Static stress changes and the triggering of earthquakes[J]. Bulletin of the Seismological Society of America, 1994, 84(3): 935-953.
[3] Harris R A, Simpson R W, Reasenberg P A. Influence of static stress changes on earthquake locations in southern California[J]. Nature, 1995, 375(6528): 221-224.
[4] Harris R A, Simpson R W. In the Shadow of 1857-the effect of the great Ft Tejon earthquake on subsequent earthquakes in Southern California[J]. Geophysical Research Letters, 1996, 23(3): 229-232.
[5] Harris R A. Introduction to special section: Stress triggers, stress shadows, and implications for seismic hazard[J]. Journal of Geophysical Research, 1998, 103(B1010): 24347-24358.
[6] Stein R S, Barka A, Dieterich J H. Progressive failure on the North Anatolian fault since 1939 by earthquake static stress triggering[J]. Geophysical Journal International, 1997, 128(3): 594-604.
[7] Toda S, Stein R S, Reasenberg F, et al. Stress transferred by the 1995 M_W=6.9 Kobe, Japan, shock: Effect on aftershocks and future earthquake probabilities[J]. Journal of Geophysical Research, 1998, 103(B1010): 24543-24565.
[8] Barka A. The 17 august 1999 Izmit earthquake[J]. Science, 1999, 285(5435): 1858-1859.
[9] Stein R S. The role of stress transfer in earthquake occurrence[J]. Nature, 1999, 402(6762): 605-609.
[10] Mccloskey J, Nalbant S S, Steacy S. Indonesian earthquake: Earthquake risk from co-seismic stress[J]. Nature, 2005, 434(7031): 291.
[11] 沈正康, 万永革, 甘卫军, 等. 东昆仑活动断裂带大地震之间的黏弹性应力触发研究[J]. 地球物理学报, 2003, 46(6): 786-795.
SHEN Zheng-kang, WAN Yong-ge, GAN Wei-jun, et al. Viscoelastic triggering among large earthquakes along the east Kunlun fault system[J]. Chinese Journal of Geophysics, 2003, 46(6): 786-795 (in Chinese).
[12] 万永革, 沈正康, 曾跃华, 等. 青藏高原东北部的库仑应力积累演化对大地震发生的影响[J]. 地震学报, 2007, 29(2): 115-129.
WAN Yong-ge, SHEN Zheng-kang, ZENG Yue-hua, et al. evolution of cumulative coulomb failure stress in northeastern Qinghai-Xizang(tibetan)[J]. Acta Seismologica Sinica, 2007, 29(2): 115-129 (in Chinese).
[13] 万永革, 盛书中, 李祥, 等. 2015年尼泊尔强震序列对中国大陆的应力影响[J]. 地球物理学报, 2015, 58(11): 4277-4286.
WAN Yong-ge, SHENG Shu-zhong, LI Xiang, et al. Stress influence of the 2015 Nepal earthquake sequence on Chinese mainland[J]. Chinese Journal of Geophysics, 2015, 58(11): 4277-4286 (in Chinese).
[14] 单斌, 熊熊, 郑勇, 等. 2013年芦山地震导致的周边断层应力变化及其与2008年汶川地震的关系[J]. 中国科学: 地球科学, 2013, 43(6): 1002-1009.
SHAN Bin, XIONG Xiong, ZHENG Yong, et al. Stress changes on major faults caused by 2013 Lushan earthquake, and its relationship with 2008 Wenchuan earthquake[J]. Science China: Earth Sciences, 2013, 43(6): 1002 -1009 (in Chinese).
[15] Parsons T, Chen J and Kirby E. Stress changes from the 2008 Wenchuan earthquake and increase hazard in the Sichuan basin[J]. Nature, 2008, 454(7203): 509-510
[16] 单斌, 熊熊, 郑勇, 等. 2008年5月12日M_W7.9汶川地震导致的周边断层应力变化[J]. 中国科学 D辑: 地球科学, 2009, 39(5): 537-545.
SHAN Bin, XIONG Xiong, ZHENG Yong, et al. Stress changes on major faults caused by M_W7.9 Wenchuan earthquake, May 12, 2008[J]. Science China: Series D-Earth Sciences, 2009, 39(5): 537-545 (in Chinese).
[17] 万永革, 沈正康, 盛书中, 等. 2008年汶川大地震对周围断层的影响[J]. 地震学报, 2009, 31(2): 128-139.
WAN Yong-ge, SHEN Zheng-kang, SHENG Shu-zhong, et al. The influence of 2008 Wenchuan earthquake on surrounding faults[J]. Acta Seismologica Sinica, 2009, 31(2): 128-139 (in Chinese).
[18] 解朝娣, 朱元清, Xinglin Lei, 等. M_S8.0汶川地震产生的应力变化空间分布及其对地震活动性的影响[J]. 中国科学: 地球科学, 2010, 40(6): 688-698.
XIE Chao-di, ZHU Yuan-qing, LEI Xing-lin, et al. Pattern of stress change and its effect on seismicity rate caused by M_S8.0 Wenchuan earthquake[J]. Science China: Earth Sciences, 2010, 40(6): 688-698 (in Chinese).
[19] 单斌, 郑勇, 刘成利, 等. 2017年M7.0级九寨沟地震同震库仑应力变化及其与2008年汶川地震的关系[J]. 中国科学: 地球科学, 2017, 47: 1329-1338.
SHAN Bin, ZHENG Yong, LIU Cheng-li, et al. Coseismic coulomb failure stress changes caused by the 2017 M_S7.0 Jiuzhaigou earthquake, and its relationship with the 2008 Wenchuan earthquake[J]. Science China: Earth Sciences, 2017, 47: 1329-1338 (in Chinese).
[20] Xie Z J, Zheng Y, Yao H J, et al. Preliminary analysis on source properties and seismogenic structure of the 2017 M_S7.0 Jiuzhaigou Earthquake[J]. Science China: Earth Sciences, 2018, 61(3): 339-352.
[21] 朱航, 屈勇. 九寨沟M_S7.0地震静态库仑应力触发及对附近断层影响分析[J]. 中国地震, 2017, 33(4): 471-479.
ZHU Hang, QU Yong. Analysis on the triggering of the Jiuzhaigou M_S7.0 earthquake’s static Coulomb stress and its influences on its adjacent faults[J]. Earthquake Research in China, 2017, 33(4): 471-479 (in Chinese).
[22] 汪建军, 许才军. 2017年M_W6.5九寨沟地震激发的同震库仑应力变化及其对周边断层的影响[J]. 地球物理学报, 2017, 60(11): 4398-4420.
WANG Jian-jun, XU Cai-jun. Coseismic Coulomb stress changes associated with the 2017 M_W6.5 Jiuzhaigou earthquake (China) and its impacts on surrounding major faults[J]. Chinese Journal of Geophysics, 2017, 60(11): 4398-4420 (in Chinese).
[23] 陈威, 乔学军, 刘刚, 等. 基于GNSS与InSAR约束的九寨沟M_S7.0地震滑动模型及其库仑应力研究[J]. 地球物理学报, 2018, 61(5): 2122-2132.
CHEN Wei, QIAO Xue-jun, LIU Gang, et al. Study on the coseismic slip model and Coulomb stress of the 2017 Jiuzhaigou M_S7.0 earthquake constrained by GNSS and InSAR measurements[J]. Chinese Journal of Geophysics, 2018, 61(5): 2122-2132 (in Chinese).
[24] 黄立人, 顾国华. 静力位错理论[M]. 北京: 地震出版社, 1982.
HUANG Li-ren, GU Guo-hua. Hydrostatic dislocation theory[M]. Beijing: Seismological Press, 1982.
[25] 张旭, 冯万鹏, 许力生, 等. 2017年九寨沟M_S7.0级地震震源过程反演与烈度估计[J]. 地球物理学报, 2017, 60(10): 4105-4116.
ZHANG Xu, FENG Wan-peng, XU Li-sheng, et al. The source-process inversion and the intensity estimation of the 2017 M_S7.0 Jiuzhaigou earthquake[J]. Chinese Journal of Geophysics, 2017, 60(10): 4105-4116 (in Chinese).
[26] 钱洪, 马声浩, 龚宇. 关于岷江断裂若干问题的讨论[J]. 中国地震, 1995, 11(2): 140-146.
QIAN Hong, MA Sheng-hao, GONG Yu. Discussions on the Minjiang fault[J]. Earthquake Research in China, 1995, 11(2): 140-146 (in Chinese).
[27] 张家声, 黄雄南, 牛向龙, 等. 川主寺—黄龙左行走滑剪切断层和松潘—平武剪切转换构造体制[J]. 地学前缘, 2010, 17(4): 15-31.
ZHANG Jia-sheng, HUANG Xiong-nan, NIU Xiang-long, et al. Chuanzhusi-Huanglong strike-slip faults and a transpressional shear system in Songpan-Pingwu Area Northwestern Sichuan, China[J]. Earth Science Frontiers, 2010, 17(4): 15-31.
[28] 鄢家全, 时振梁, 汪素云, 等. 中国及邻区现代构造应力场的区域特征[J]. 地震学报, 1979, 1(1): 9-24.
YAN Jia-quan, SHI Zhen-liang, WANG Su-yun, et al. Some features of the recent tectonic stress field of China and environs[J]. Acta Seismologica Sinica, 1979, 1(1): 9-24 (in Chinese).
[29] 张军龙, 任金卫, 付俊东, 等. 东昆仑断裂带东部塔藏断裂地震地表破裂特征及其构造意义[J]. 地震, 2012, 32(1): 1-16.
ZHANG Jun-long, REN Jin-wei, FU Jun-dong, et al. Earthquake rupture features and tectonic significance of the Tazang fault in the eastern part of the east Kunlun fault zones[J]. Earthquake, 2012, 32(1): 1-16 (in Chinese).
[30] 付国超, 张军龙, 蔡瑶瑶. 塔藏断裂马家磨段晚第四纪以来活动性研究[J]. 地震, 2017, 37(3): 51-60.
FU Guo-chao, ZHANG Jun-long, CAI Yao-yao. Late quaternary tectonic activity on the Majiamo segment of the Tazang fault[J]. Earthquake, 2017, 37(3): 51-60 (in Chinese).
[31] 曹俊, 彭东, 郭建强, 等. 塔藏构造混杂岩带特征[J]. 中国地质, 2002, 29(4): 387-391.
CAO Jun, PENG Dong, GUO Jian-qiang, et al. Characteristics of the Tazang tectonic mélange belt[J]. Geology in China, 2002, 29(4): 387-391 (in Chinese).
[32] 卢海峰, 马保起, 刘光勋. 甘肃文县北部北东东向断裂带新构造活动特征[J]. 地震研究, 2006, 29(2): 143-146.
LU Hai-feng, MA Bao-qi, LIU Guang-xun. Characteristics of the Neotectonic movement of the NEE-striking fault belt north of Wen county, Gansu[J]. Journal of Seismological Research, 2006, 29(2): 143-146.
[33] 郭祥云, 陈学忠, 李艳娥. 2008 年5 月12 日四川汶川8.0级地震与部分余震的震源机制解[J]. 地震, 2010, 30(1): 50-60 (in Chinese).
GUO Xiang-yun, CHEN Xue-zhong, LI Yan-e. Focal mechanism solutions for the 2008 M_S8.0 Wenchuan earthquake and part of its aftershocks[J]. Earthquake, 2010, 30(1): 50-60 (in Chinese).