基于库仑应力变化分析2015年尼泊尔MS8.1地震对中国大陆的影响

摘要/Abstract

摘要： 本文采用分层黏弹性介质模型, 模拟了2015年4月25日尼泊尔M_S8.1地震产生的同震和震后地表位移场, 计算了尼泊尔大地震引起的青藏高原及其周缘主要断裂上的同震和震后库仑应力变化。地表位移场结果显示, 此次尼泊尔8.1级地震对中国大陆的影响区域主要是拉萨地块和羌塘地块, 对拉萨块体的影响主要表现为水平向南朝喜马拉雅构造带的汇聚作用, 垂直同震位移以下降为主, 震后以上升为主。静态库仑破裂应力变化的计算结果显示, 尼泊尔大地震对青藏块体中南部的拉张性断层影响最为显著, 其中, 使尼泊尔地震北部的拉张断层的库仑应力显著增加, 个别断层库仑应力增加量超过0.01MPa, 而使其两侧的拉张断层库仑应力明显降低; 对青藏块体中部的走滑断裂则以正影响为主; 另外, 对南北地震带主要以负影响为主, 但量值微小。

关键词: 库仑破裂应力变化, 青藏块体, 断层相互作用, 2015年尼泊尔8.1级地震, 中国大陆

Abstract: Using the multi-layered viscoelastic media, we simulated coseismic and postseismic surface displacements caused by the April 25, 2015 Nepal M_S8.1 earthquake, and then calculated the Coulomb failure stress changes on major faults of the Tibetan plateau and its surrounding caused by the coseismic dislocation and postseismic viscoelastic relaxation effects of the Nepal large earthquake. The surface displacement shows that the Nepal large earthquake mainly influences the Lhasa block and Qiangtang block, making the Lhasa block converge to the Himalayan tectonic belt. Vertical displacements of the Lhasa block predominately drop down in the coseismic stage and rise up in the postseismic stage. The calculated results of the static Coulomb failure stress changes indicate that, the Nepal large earthquake significantly influence tensional faults in central and southern Tibetan plateau, among the faults, the tension faults in the north of the Nepal earthquake take a significant increasing of Coulomb stress and the Coulomb stress in some specific fault segments increase more than 0.01 MPa, while the tension faults on both sides of the earthquake have a significant decreasing of Coulomb stress. In addition, Coulomb stress changes on the strike-slip faults in central Tibetan plateau are mainly increased which has been caused by the Nepal large earthquake, however, Coulomb stress changes on the faults of the North-South Seismic Belt are mainly slightly decreased by the Nepal large earthquake.

Key words: Interactions between faults, Coulomb failure stress changes, Tibetan Plateau, The 2015 Nepal M_S8.1 earthquake

中图分类号:

P315.7

徐晶, 李海艳, 邵志刚, 冯建刚, 张竹琪. 基于库仑应力变化分析2015年尼泊尔M_S8.1地震对中国大陆的影响[J]. 地震, 2016, 36(1): 69-77.

XU Jing, LI Hai-yan, SHAO Zhi-gang, FENG Jian-gang, ZHANG Zhu-qi. Effects of the 2015 Nepal M_S8.1 Earthquake on Mainland China based on Coulomb Stress Changes[J]. EARTHQUAKE, 2016, 36(1): 69-77.

参考文献

[1] Bilham R, Vinod K, Molnar P. Himalayan Seismic Hazard[J]. Science, 2001, 293: 1442-1444.
[2] 盛书中, 万永革, 蒋长胜, 等. 2015年尼泊尔M_S8.1强震对中国大陆静态应力触发影响的初探[J]. 地球物理学报, 2015, 58(5): 1834-1842.
[3] 张贝, 程惠红, 石耀霖. 2015年4月25日尼泊尔M_S8.1大地震的同震效应[J]. 地球物理学报, 2015, 58(5): 1794-1803.
[4] Reasenberg P A, Simpson R W. Response of regional seismicity to the static stress change produced by the Loma Prieta Earthquake [J]. Science, 1992, 255(5052): 1687-1690.
[5] 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: 935-980.
[6] Ma K F, Chan C H, Stein R S. Response of seismicity to Coulomb stress triggers and shadows of the 1999 M_W=7.6 Chi-Chi, Taiwan, earthquake[J]. J Geophys Res, 2005, 110: B05S19.
[7] 刘桂萍, 傅征祥. 海原大地震对古浪大地震的静应力触发研究[J]. 地球物理学报, 2001, 44(增刊): 107-115.
[8] 华卫, 刘杰, 郑斯华, 等. 2003年云南大姚6.2、 6.1级地震序列特征分析及地震触发研究[J]. 中国地震, 2006, 22(1): 10-23.
[9] 张竹琪, 陈永顺, 林间. 1997年伽师震群中相邻正断层和走滑断层之间相互应力作用[J]. 中国科学D辑: 地球科学, 2008, 38(3): 334-342.
[10] 韩竹军, 董绍鹏, 谢富仁. 南北地震带北部5次(1561～1920年)M≥7级地震触发关系研究[J]. 地球物理学报, 2008, 51(6): 1776-1784.
[11] 朱航, 闻学泽. 1973～1976年四川松潘强震序列的应力触发过程[J]. 地球物理学报, 2009, 52(4): 994-1003.
[12] Robinson R, Zhou S. Stress interactions within the Tangshan, China, earthquake sequence of 1976 [J]. Bull Seism Soc Am, 2005, 95: 2501-2505.
[13] 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.
[14] 邵志刚, 周龙泉, 蒋长胜, 等. 2008年汶川M_S8.0地震对周边断层地震活动的影响[J]. 地球物理学报, 2010, 53(8): 1784-1795.
[15] Freed A, Lin J. Delayed triggering of the 1999 Hector Mine earthquake by viscoelastic stress transfer[J]. Nature, 2001, 411: 180-183.
[16] Zeng Y. Viscoelastic stress-triggering of the 1999 Hector Mine earthquake by the 1992 Landers earthquake[J]. Geophysical Research Letters, 2001, 28(15): 3007-3010.
[17] Pollitz F F, Sacks I S. Stress trigger of the 1999 Hector Mine Earthquake by transient deformation following the 1992 Landers Earthquake[J]. Bulletin of the Seismological Society of America, 2002, 92(4): 1487-1496.
[18] Stein R S, Barka A A, Dieterich J H. Progressive failure on the North Anatolian fault since 1939 by earthquake stress triggering[J]. Geophysical Journal International, 1997, 128: 594-604.
[19] Nalbant S S, Hubert A, King G C P. Stress coupling between earthquakes in Northwest Turkey and the North Aegean Sea[J]. Journal of Geophysical Research, 1998, 103: 24469-24486.
[20] Ali S T, Freed A M, Calais E, et al. Coulomb stress evolution in Northeastern Caribbean over the past 250 years due to coseismic, postseismic and interseismic deformation[J]. Geophysical Journal International, 2008, 174(3): 904-918.
[21] Toda S, Lin J, Meghraoui M, et al. 12 May 2008 M=7.9 Wenchuan, China, earthquake calculated to increase failure stress and seismicity rate on three major fault systems[J]. Geophysical Research Letters, 2008, 35: L17305.
[22] 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), 2009, 39(5): 537-545.
[23] 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.
[24] 徐晶, 邵志刚, 马宏生, 等. 鲜水河断裂带库仑应力演化与强震间关系[J]. 地球物理学报, 2013, 56(4): 1146-1158.
[25] 徐晶, 邵志刚, 马宏生, 等. 汶川8.0级地震和芦山7.0级地震对周边断层的影响[J]. 地震, 2014, 34(4): 40-49.
[26] Harris R A. Introduction to special section: Stress triggers, stress shallows, and implications for seismic hazard [J]. Journal of Geophysical Research, 1998, 103(B10): 24347-24358.
[27] Jaeger J C, Cook N G W. Fundamentals of Rock Mechanics[M]. New York, 1969.
[28] 蔡美琴. 岩石力学与工程[M]. 北京: 科学出版社, 2002.
[29] Deng J, Gurnis M, Kanamori H, et al. Viscoelastic flow in the lower crust after the 1992 Landers, California, Earthquake[J]. Science, 1998, 282(27): 1689-1692.
[30] Bassin C, Laske G, Masters G. The current limits of resolution for surface wave tomography in North America[J]. EOS Trans., 2000, AGU 81, F897.
[31] Shao Z G, R J Wang, Wu Y Q, et al. Rapid afterslip and short-term viscoelastic relaxation following the 2008 M_W7.9 Wenchuan earthquake[J]. Earthq Sci, 2011, 24: 163-175.
[32] Wang R J, Lorenzo-Martin F, Roth F. PSGRN/PSCMP-a new code for calculating co- and post-seismic deformation, geoid and gravity changes based on the viscoelastic-gravitational dislocation theory[J]. Computers & Geosciences, 2006, 32: 527-541.
[33] 张勇, 许力生, 陈运泰. 2015年尼泊尔M_W7.9地震破裂过程: 快速反演与初步联合反演[J]. 地球物理学报, 2015, 58(5): 1804-1811.
[34] Yin A. Cenozoic tectonic evolution of the Himalayan orogen as constrained by along-strike variation of structural geometry, exhumation history, and foreland sedimentation[J]. Earth-Science Review, 2006, 76: 1-131.
[35] 邓起东, 张培震. 中国活动构造基本特征[J]. 中国科学: D辑, 2002, 32(12): 1020-1030.
[36] 占伟, 武艳强, 梁洪宝, 等. GPS观测结果反映的尼泊尔M_W7.8地震孕震特征[J]. 地球物理学报, 2015, 58(5): 1818-1826.