汶川8.0和芦山7.0级地震序列应力场时空特征

doi:10.3969/j.issn.0253-4967.2015.03.011

摘要/Abstract

摘要：

分别基于汶川M≥4.0和芦山M≥3.0余震震源机制解, 采用Michael提出的应力场反演方法, 分析了汶川、芦山余震区压应力(S₁)和应力张量方差的空间分布特征, 研究了应力张量方差时空变化与强余震活动的关系.结果表明: 1)汶川、芦山余震区S₁方位复杂, 存在显著的空间分区差异, 主震起始破裂区附近S₁方位相对紊乱, 应力张量方差明显偏高; 2)汶川余震区自西南至东北, S₁方位由近EW向逐渐转变为NW-SE向, 最后在余震区的北段又转为近EW向, 应力类型均呈逆断型, 而理县分支S₁方位呈NEE向, 应力类型为走滑型, 整个余震区S₁呈近水平特征; 3)芦山余震区S₁方位总体呈现NW向, 倾角近水平, 除主震震中附近的应力类型为纯逆断型外, 其他区域走滑型和逆断型的应力类型均有存在; 4)应力张量方差时空分布对于强余震的发生具有一定的指示意义, 汶川、芦山强余震均发生在应力张量方差低值分布区或其边缘附近, 且汶川强余震的发震时间也在其出现低值的时段.

关键词: 汶川地震, 芦山地震, 震源机制, 压应力, 应力张量方差

Abstract:

Based on focal mechanism solutions of Wenchuan M≥4.0 and Lushan M≥3.0 aftershocks, using inversion method of stress field to analyze the spatial distribution characteristic of compressive stress (S₁) and stress tensor variance of Wenchuan and Lushan aftershock zones, the relation between spatial and temporal distribution of stress tensor variance and strong aftershock activity are studied. The results show that (1) The orientations of compressive stress (S₁) are complex in Wenchuan and Lushan aftershock zones, there exists obvious regional difference spatially, the S₁ orientations all present disorder feature near the main shock rupture zone, and the stress tensor variances are obviously higher. (2)Along Wenchuan aftershock zone from southwest to northeast, the compressive stress orientation gradually changes from EW to NW-SE, finally, it presents near EW direction at north segment of aftershock zone, and the stress type is all thrust; the S₁ orientation presents NEE direction in Lixian branch of Wenchuan aftershock zone, the stress type shows strike-slip type, the compressive stress presents a near horizontal feature in whole aftershock zone. (3)The compressive stress orientation presents NW direction in Lushan aftershock zone, the dip angle is near horizontal, the stress type is thrust near the main shock and strike-slip and thrust in other areas. (4)The spatial and temporal distribution of stress tensor variance has certain indicative significance for occurrence of strong aftershock, most later-phase strong aftershocks of Wenchuan and Lushan earthquake occurred in the low-value area of stress tensor variance and its fringe areas, the origin time of Wenchaun strong aftershocks are also at the time frame of low value of stress tensor variance.

Key words: Wenchuan earthquake, Lushan earthquake, focal mechanism solutions, compressive stress, stress tensor variance

中图分类号:

P315.72⁺7

张致伟, 周龙泉, 龙锋, 阮祥. 汶川8.0和芦山7.0级地震序列应力场时空特征[J]. 地震地质, 2015, 37(3): 804-817.

ZHANG Zhi-wei, ZHOU Long-quan, LONG Feng, RUAN Xiang. SPATIAL AND TEMPORAL CHARACTERISTIC OF STRESS FIELD FOR WENCHUAN M_S8.0 AND LUSHAN M_S7.0 EARTHQUAKE SEQUENCE[J]. SEISMOLOGY AND GEOLOGY, 2015, 37(3): 804-817.

参考文献

陈颙. 1978. 用震源机制一致性作为描述地震活动性的新参数［J］. 地球物理学报, 21(2): 146—159.
CHEN Yong. 1978. Consistency of focal mechanism as a new parameter in describing seismic activity［J］. Acta Geophysica Sinica, 21(2): 146—159(in Chinese).
陈运泰, 杨智娴, 张勇, 等. 2013. 从汶川地震到芦山地震［J］. 中国科学(D辑), 43(6): 1064—1072.
CHEN Yun-tai, YANG Zhi-xian, ZHANG Yong, et al. 2013. From 2008 Wenchuan earthquake to 2013 Lushan earthquake［J］. Scientia Sinica Terrae(Ser D), 43(6): 1064—1072(in Chinese).
成尔林. 1981. 四川及其邻区现代构造应力场和现代构造运动特征［J］. 地震学报, 3(3): 231—241.
CHENG Er-lin. 1981. Recent tectonic stress field and tectonic movement of the Sichuan Province and its vicinity［J］. Acta Seismologica Sinica, 3(3): 231—241(in Chinese).
刁桂苓, 徐锡伟, 陈于高, 等. 2011. 汶川MW7.9和集集MW7.6 地震前应力场转换现象及其可能的前兆意义［J］. 地球物理学报, 54(1): 128—136.
DIAO Gui-ling, XU Xi-wei, CHEN Yu-gao, et al. 2011. The precursory significance of tectonic field transformation before the Wenchuan MW7.9 earthquake and the Chi-Chi MW7.6 earthquake［J］. Chinese J Geophys, 54(1): 128—136(in Chinese).
高原, 王琼, 赵博, 等. 2013. 龙门山断裂带中南段的一个破裂空段: 芦山地震的震后效应［J］. 中国科学(D辑), 43(6): 1038—1046.
GAO Yuan, WANG Qiong, ZHAO Bo, et al. 2013. A rupture blank zone in middle south part of Longmenshan faults: Effect after Lushan MS7.0 earthquake of 20 April 2013 in Sichuan, China［J］. Science in China(Ser D), 43(6): 1038—1046(in Chinese).
阚荣举, 张四昌, 晏凤桐, 等. 1977. 中国西南地区现代构造应力场与现代构造活动特征的探讨［J］. 地球物理学报, 20(2): 96—109.
KAN Rong-ju, ZHANG Si-chang, YAN Feng-tong, et al. 1977. Present tectonic stress field and its relation to the characteristics of recent tectonic activity in southwestern China［J］. Acta Geophusica Sinica, 20(2): 96—109(in Chinese).
李勇, 黄润秋, 周荣军, 等. 2009. 龙门山地震带的地质背景与汶川地震的地表破裂［J］. 工程地质学报, 17(1): 3—16.
LI Yong, HUANG Run-qiu, ZHOU Rong-jun, et al. 2009. Geological background of Longmenshan seismic belt and surface ruptures in Wenchuan earthquake［J］. Journal of Engineering Geology, 17(1): 3—16(in Chinese).
林向东, 葛洪魁, 徐平, 等. 2013. 近场全波形反演: 芦山7.0级地震及余震矩张量解［J］. 地球物理学报, 56(12): 4037—4047.
LIN Xiang-dong, GE Hong-kui, XU-ping, et al. 2013. Near field full waveform inversion: Lushan magnitude 7.0 earthquake and its aftershock moment tensor［J］. Chinese J Geophys, 56(12): 4037—4047(in Chinese).
梁尚鸿, 李幼铭, 束沛镒, 等. 1984. 利用区域地震台网P、S振幅比资料测定小震震源参数［J］. 地球物理学报, 27(3): 249—257.
LIANG Shang-hong, LI You-ming, SHU Pei-yi, et al. 1984. On the determining of source parameters of small earthquakes by using amplitude ratios of P and S from regional network observations［J］. Chinese J Geophys, 27(3): 249—257(in Chinese).
罗艳, 倪四道, 曾祥方, 等. 2010. 汶川地震余震区东北端一个余震序列的地震学研究［J］. 中国科学(D辑), 40(6): 677—687.
LUO Yan, NI Si-dao, ZENG Xiang-fang, et al. 2010. A shallow aftershock sequence in the northeastern end of the Wenchuan earthquake aftershock zone［J］. Science in China(Ser D), 40(6): 677—687(in Chinese).
吕坚, 王晓山, 苏金蓉, 等. 2013. 芦山7.0级地震序列的震源位置与震源机制解特征［J］. 地球物理学报, 56(5): 1753—1763.
Lü Jian, WANG Xiao-shan, SU Jin-rong, et al. 2013. Hypocentral location and source mechanism of the MS7.0 Lushan earthquake sequence［J］. Chinese J Geophys, 56(5): 1753—1763(in Chinese).
王俊国, 刁桂苓. 2005. 千岛岛弧大震前哈佛大学矩心矩张量(CMT)解一致性的预测意义［J］. 地震学报, 27(2): 178—183(in Chinese).
WANG Jun-guo, DIAO Gui-ling. 2005. Consistent CMT solutions from Harvard University before the great earthquakes in Kurile Islands and its significance for earthquake prediction［J］. Acta Seismologica Sinica, 27(2): 178—183(in Chinese).
王勤彩, 陈章立, 郑斯华. 2009. 汶川大地震余震序列震源机制的空间分段特征［J］. 科学通报, 54(16): 2348—2354.
WAGN Qin-cai, CHEN Zhang-li, ZHENG Si-hua. 2009. Spatial segmentation characteristic of focal mechanism of aftershock sequence of Wenchuan earthquake［J］. Chinese Sci Bull, 54(16): 2348—2354(in Chinese).
闻学泽, 张培震, 杜方, 等. 2009. 2008年汶川8.0级地震发生的历史与现今地震活动背景［J］. 地球物理学报, 52(2): 444—454.
WEN Xue-ze, ZHANG Pei-zhen, DU Fang, et al. 2009. The background of historical and modern seismic activities of the occurrence of the 2008 MS8.0 Wenchuan, Sichuan, earthquake［J］. Chinese J Geophys, 52(2): 444—454(in Chinese).
谢富仁, 崔效锋, 赵建涛, 等. 2004. 中国大陆及邻区现代构造应力场分区［J］. 地球物理学报, 47(4): 654—662.
XIE Fu-ren, CUI Xiao-feng, ZHAO Jian-tao, et al. 2004. Regional division of the recent tectonic stress field in China and adjacent areas［J］. Chinese J Geophys, 47(4): 654—662(in Chinese).
徐锡伟, 陈桂华, 于贵华, 等. 2013. 芦山地震发震构造及其与汶川地震关系讨论［J］. 地学前缘, 20(3): 11—20.
XU Xi-wei, CHEN Gui-hua, YU Gui-hua, et al. 2013. Seismogenic structure of Lushan earthquake and its relationship with Wenchuan earthquake［J］. Earth Science Frontiers, 20(3): 11—20(in Chinese).
徐锡伟, 闻学泽, 叶建青, 等. 2008. 汶川MS8.0地震地表破裂带及其发震构造［J］. 地震地质, 30(3): 597—629.
XU Xi-wei, WEN Xue-ze, YE Jian-qing, et al. 2008. The MS8.0 Wenchuan earthquake surface ruptures and its seismogenic structure［J］. Seismology and Geology, 30(3): 597—629(in Chinese).
徐锡伟, 闻学泽, 韩竹军, 等. 2013. 四川芦山7.0级强震: 一次典型的盲逆断层型地震［J］. 科学通报, 58(20): 1887—1893.
XU Xi-wei, WEN Xue-ze, HAN Zhu-jun, et al. 2013. Lushan MS7.0 earthquake: A blind reserve-fault earthquake［J］. Chin Sci Bull, 58(20): 1887—1893(in Chinese).
徐锡伟, 张培震, 闻学泽, 等. 2005. 川西及其邻近地区活动构造基本特征与强震复发模型［J］. 地震地质, 27(3): 446—461.
XU Xi-wei, ZHANG Pei-zhen, WEN Xue-ze, et al. 2005. Characteristics of active tectonics and models of earthquake recurrence in western Sichuan［J］. Seismology and Geology, 27(3): 446—461(in Chinese).
许忠淮, 戈澍谟. 1984. 用滑动方向拟合法反演富蕴地震断裂带应力场［J］. 地震学报, 6(4): 395—404.
XU Zhong-huai, GE Shu-mo. 1984. Stress field in the Fuyun, Xinjiang earthquake fracture zone determined by fitting fault slip vector data［J］. Acta Seismologica Sinica, 6(4): 395—404(in Chinese).
徐忠淮, 汪素云, 黄雨蕊, 等. 1987. 由多个小震推断的青甘和川滇地区地壳应力场的方向特征［J］. 地球物理学报, 30(5): 476—486.
XU Zhong-huai, WANG Su-yun, HUANG Yu-rui, et al. 1987. Directions of mean stress axes in southwestern China deduced from micro-earthquake data［J］. Acta Geophysica Sinica, 30(5): 476—486(in Chinese).
易桂喜, 龙锋, 张致伟. 2012. 汶川MS8.0地震余震震源机制时空分布特征［J］. 地球物理学报, 55(4): 1213—1227.
YI Gui-xi, LONG Feng, ZHANG Zhi-wei. 2012. Spatial and temporal variation of focal mechanisms for aftershocks of the 2008 MS8.0 Wenchuan earthquake［J］. Chines J Geophys, 55(4): 1213—1227(in Chinese).
泽仁志玛, 刁桂苓, 李志雄, 等. 2009. 千岛岛弧2006年MW8.3地震震前震源机制解的一致性变化［J］. 地震学报, 31(4): 467—470.
ZEREN Zhi-ma, DIAO Gui-ling, LI Zhi-xiong, et al. 2009. Variation of focal mechanism consistency before 2006 Kuril Islands arc MW8.3 earthquake［J］. Acta Seismologica Sinica, 31(4): 467—470(in Chinese).
张培震, 徐锡伟, 闻学泽, 等. 2008. 2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因［J］. 地球物理学报, 51(4): 1066—1073.
ZHANG Pei-zhen, XU Xi-wei, WEN Xue-ze, et al. 2008. Slip rates and recurrence intervals of the Longmen Shan active fault zone, and tectonic implications for the mechanism of the May 12 Wenchuan earthquake, 2008, Sichuan, China［J］. Chinese J Geophys, 51(4): 1066—1073(in Chinese).
赵博, 高原, 黄志斌, 等. 2013. 四川芦山MS7.0地震余震序列双差定位、震源机制及应力场反演［J］. 地球物理学报, 56(10): 3385—3395.
ZHAO Bo, GAO Yuan, HUANG Zhi-bin, et al. 2013. Double difference relocation, focal mechanism and stress inversion of Lushan MS7.0 earthquake sequence［J］. Chinese J Geophys, 56(10): 3385—3395(in Chinese).
郑勇, 马宏生, 吕坚, 等. 2009. 汶川地震强余震(MS≥5.6)的震源机制解及其与发震构造的关系［J］. 中国科学(D辑), 39(4): 413—426.
ZHENG Yong, MA Hong-sheng, Lü Jian, et al. 2009. Source mechanism of strong aftershocks(MS≥5.6)of the 2008/05/12 Wenchuan earthquake and the implication for seismotectonics［J］. Science in China(Ser D), 39(4): 413—426(in Chinese).
钟继茂, 程万正. 2006. 由多个地震震源机制解求取川滇地区平均应力场方向［J］. 地震学报, 28(4): 337—346.
ZHONG Ji-mao, CHENG Wan-zheng. 2006. Determination of directions of the mean stress field in Sichuan-Yunnan region from a number of focal mechanism solutions［J］. Acta Seismologica Sinica, 28(4): 337—346(in Chinese).
Gephart J W, Forsyth D W. 1984. An improved method for determining the regional stress tensor using earthquake focal mechanism data: Application to the San Fernando earthquake sequence［J］. J Geophys Res, 89: 9305—9320.
Hardebeck J L, Hauksson E. 2001. Stress orientations obtained from earthquake focal mechanisms: What are appropriate uncertainty estimates?［J］. Bull Seism Soc Am, 91: 250—262.
Hardebeck J L, Michael A J. 2006. Damped regional-scale stress inversion: Methodology and examples for southern California and the Coalinga aftershock sequence［J］. J Geophys Res, 111(B11310): 1—11.
Lu Z, Wyss M, Pulpan H. 1997. Detail of stress directions in the Alaska subduction zone from fault plane solutions［J］. J Geophys Res, 102: 5383—5402.
Michael A J. 1984. Determination of stress from slip data: Faults and folds［J］. J Geophys Res, 89(B13): 11, 517-11, 526.
Michael A J. 1987. Use of focal mechanisms to determine stress: A control study［J］. J Geophys Res, 92(B1): 357—368.
Michael A J. 1991. Spatial variations of stress within the 1987 Whittier Narrows, California, aftershock sequence: New techniques and results［J］. J Geophys Res, 96: 6303—6319.
Wiemer S, Gerstenberger M, Hauksson E. 2002. Properties of the aftershock sequence of the 1999 MW7.1 Hector Mine earthquake: Implications for aftershock hazard［J］. Bulletin of the Seismological Society of America, 92(4): 1227—1240.
Zhao L S, Helmberger D V. 1994. Source estimation from broadband regional seismograms［J］. Bull Seismol Soc Amer, 84(1): 91—104.
Zhu L P, Helmberger D V. 1996. Advancement in source estimation techniques using broadband regional seismograms［J］. Bull Seismol Soc Amer, 86(5): 1634—1641.

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