2019年6月17日长宁MS6.0地震序列震源区二维构造应力场特征研究

doi:10.12196/j.issn.1000-3274.2022.01.001

摘要/Abstract

摘要： 使用近震波形反演方法求解2019年6月17日四川长宁Ms6.0地震序列的震源机制解和震源深度, 共得到30个可靠的M>3.0地震震源机制解和震源深度, 结合该地区已有的震源机制解, 开展震源区构造应力场反演, 小尺度探讨震源区的构造应力环境。反演结果显示, 震中附近区域主要以逆冲型应力性质为主, 局部地区包括少量走滑分量以及混合类型。最大主压应力方向主要以NEE向或NE向为主。在筠连以东地区, 不同于北部的逆冲型, 应力性质以走滑型兼少量混合类型为主, 最大主压应力方向近EW向。构造应力场方向与形成长宁背斜的构造应力存在一定交角, 2019年长宁6.0级地震可能是由NE或NEE向近水平应力挤压产生的该地区滑脱面之上背斜核部的逆断层活动造成的。

关键词: 2019年长宁M_S6.0地震, 震源机制解, 构造应力场

Abstract: The focal mechanism solution and focal depth of the Changning M_S6.0 earthquake sequence in Sichuan on June 17, 2019 were solved using the near-earthquake waveform inversion method, and a total of 30 reliable focal mechanism solutions and focal depths of the earthquakes with M>3.0 were obtained. Combining with the existing focal mechanism solutions in the area, we carry out the inversion of the tectonic stress field in the focal area, and explore the tectonic stress environment in the focal area on a small scale. The inversion results show that the area near the epicenter is dominated by thrust-type stress, and some areas include a small amount of strike-slip components and mixed types. The direction of the maximum principal compressive stress is mainly in the direction of NEE or NE. In the area to the east of Junlian, unlike the thrust type in the north, the stress properties are mainly strike-slip type with a small amount of mixed type, and the maximum principal compressive stress direction is close to the EW direction. There is a certain angle between the direction of the tectonic stress field and the tectonic stress forming the Changning anticline. The 2019 Changning M_S6.0 earthquake may be caused by the reverse fault activity at the core of the anticline above the detachment surface of the area caused by the NE or NEE approaching horizontal stress compression.

Key words: 2019 Changning M_S6.0 earthquake, Focal mechanism solution, Tectonic stress field

中图分类号:

P315.7

田建慧, 罗艳. 2019年6月17日长宁M_S6.0地震序列震源区二维构造应力场特征研究[J]. 地震, 2022, 42(1): 1-17.

TIAN Jian-Hui, LUO Yan. Study on the Characteristics of the Two-dimensional Tectonic Stress Field in the Focal Area of the Changning M_S6.0 Earthquake Sequence on June 17, 2019[J]. EARTHQUAKE, 2022, 42(1): 1-17.

参考文献

[1] 王适择. 川南长宁地区构造特征及志留系龙马溪组裂缝特征研究[D]. 成都理工大学, 2014.
WANG Shi-ze. The tectonic background of the shale fracture development in Silurian Longmaxi formation in Changning Region of Southern Sichuan[D]. Chengdu University of Technology, 2014 (in Chinese).
[2] 何登发, 鲁人齐, 黄涵宇, 等. 长宁页岩气开发区地震的构造地质背景[J]. 石油勘探与开发, 2019, 46(5): 993-1006.
HE Deng-fa, LU Ren-qi, HUANG Han-yu, et al. Tectonic and geological background of the earthquake hazards in Changning shale gas development zone, Sichuan Basin, SW China[J]. Petroluem Exporation and Development, 2019, 46(5): 993-1006 (in Chinese).
[3] 钱洪, 唐荣昌. 四川盆地的地震地质特征[J]. 四川地震, 1992, (3): 13-18.
QIAN Hong, TANG Rong-chang. Seismo-geological features of the Sichuan Basin[J]. Earthquake Research in Sichuan, 1992, (3): 13-18 (in Chinese).
[4] 张致伟, 龙锋, 王世元, 等. 四川宜宾地区地震定位及速度结构[J]. 地震地质, 2019, 41(4): 913-926.
ZHANG Zhi-wei, LONG Feng, WANG Shi-yuan, et al. Earthquake location and velocity structure in Yibin area, Sichuan[J]. Seismology and Geology, 2019, 41(4): 913-926 (in Chinese).
[5] 张培震, 闻学泽, 徐锡伟, 等. 2008年汶川8.0级特大地震孕育和发生的多单元组合模式[J]. 科学通报, 2009, 54(7): 944-953.
ZHANG Pei-zhen, WEN Xue-ze, Xu Xi-wei, et al. Tectonic model of the great Wenchuan earthquake of May 12, 2008, Sichuan, China[J]. Chinese Science Bulletin, 2009, 54(7): 944-953 (in Chinese).
[6] 胡晓辉, 盛书中, 万永革, 等. 2019年6月17日四川长宁地震序列震源机制与震源区震后构造应力场研究[J]. 地球物理学进展, 2020, 35(5): 1675-1681.
HU Xiao-hui, SHENG Shu-zhong, WAN Yong-ge, et al. Study on focal mechanism and post-seismic tectonic stress field of the Changning, Sichuan, earthquake sequence on June 17^th 2019[J]. Progress in Geophysics, 2020, 35(5): 1675-1681 (in Chinese).
[7] 刘敬光, 万永革, 黄志斌, 等. 2019年6月17日四川长宁6.0级地震中心震源机制解及震源区构造应力场研究[J]. 震灾防御技术, 2019, 14(3): 677-685.
LIU Jing-guang, WAN Yong-ge, HUANG Zhi-bin, et al. Study on central focal mechanism and its surrounding tectonic stress field of the Changning M6.0 earthquake in Sichuan[J]. Technology for Earthquake Disaster Prevention, 2019, 14(3): 677-685 (in Chinese).
[8] 易桂喜, 龙锋, 梁明剑, 等. 2019年6月17日四川长宁M_S6.0地震序列震源机制解与发震构造分析[J]. 地球物理学报, 2019, 62(9): 3432-3447.
YI Gui-xi, LONG Feng, LIANG Ming-jian, et al. Focal mechanism solutions and seismogenic structure of the 17 June 2019 M_S6.0 Sichuan Changning earthquake sequence[J]. Chinese Journal of Geophysics, 2019, 62(9): 3432-3447 (in Chinese).
[9] Zhao L S, Helmberger D V. Source estimation from broad-band regional seismograms[J]. Bulltin of the Seismological Society of America, 1994, 84(1): 91-104.
[10] Zhu L P, Helmberger D V. Advancement in source estimation techniques using broadband regional seismograms[J]. Bulltin of the Seismological Society of America, 1996, 86(5): 1634-1641.
[11] Tian J H, Luo Y, Zhao L. Regional stress field in Yunnan revealed by the focal mechanisms of moderate and small earthquakes[J]. Earth and Planetary Physics, 2019, 3(3): 1-10.
[12] Luo Y, Zhao L, Tian J H. Spatial and temporal variations of stress field in the Longmenshan fault zone after the 2008 Wenchuan, China earthquake[J]. Tectonophysics, 2019, 767: 228172.
[13] 田建慧, 罗艳. 中国大陆及其周边地区应力场特征[J]. 地震, 2019, 39(2): 110-121.
TIAN Jian-hui, LUO Yan. Characteristics of stress field in mainland China and surrounding areas[J]. Earthquake, 2019, 39(2): 110-121 (in Chinese).
[14] 崔子健, 陈章立, 王勤彩, 等. 南北地震带地震震源机制解和现今应力特征[J]. 地震, 2019, 39(1): 1-10.
CUI Zi-jian, CHEN Zhang-li, WANG Qin-cai, et al. Characteristics of focal mechanism and stress in the north-south seismic belt of China[J]. Earthquake, 2019, 39(1): 1-10 (in Chinese).
[15] 李君, 王勤彩. 2013年松原5级震群序列精定位、震源机制解及发震构造特征[J]. 地震, 2018, 38(4): 62-73.
LI Jun, WANG Qin-cai. Reloation and focal mechanism of the Songyuan earthquake swarm sequence in 2013[J]. Earthquake, 2018, 38(4): 62-73.
[16] 钱晓东, 秦家政, 刘丽芳. 云南地区现代构造应力场研究[J]. 地震地质, 2011, 33(1): 91-106.
QIAN Xiao-dong, QIN Jia-zheng, LIU Li-fang. Study on recent tectonic stress field in Yunnan region[J]. Earthquake and Geology, 2011, 33(1): 91-106 (in Chinese).
[17] Zhu L P, Rivera L A. A note on the dynamic and static displacements from a point source in multi-layered media[J]. Geophysical Journal International, 2002, 148(2): 619-627.
[18] Kagan Y Y. 3-D rotation of double-couple earthquake sources[J]. Geophysical Journal International, 1991, 106(3): 709-716.
[19] 万永革. 美国Landers地震和Hector Mine地震前震源机制与主震机制一致现象的研究[J]. 中国地震, 2008, 24(3): 216-225.
WAN Yong-ge. Study on consistency of focal mechanism of mainshock and that of preshocks in landers and hector mine earthquake in United States[J]. Earthquake Research in China, 2008, 24(3): 216-225 (in Chinese).
[20] 万永革. 同一地震多个震源机制中心解的确定[J]. 地球物理学报, 2019, 62(12): 4718-4728.
WAN Yong-ge. Determination of center of several focal mechanisms of the same earthquake[J]. Chinese Journal of Geophysics, 2019, 62(12): 4718-4728 (in Chinese).
[21] Angelier J. Determination of the mean principal directions of stresses for a given fault population[J]. Tectonophysics, 1979, 56(3-4): T17-T26.
[22] Angelier J. Tectonic analysis of fault slip data sets[J]. Journal of Geophysical Research Solid Earth, 1984 89(B7): 5835-5848.
[23] Gephart J W, Forsyth D W. An improved method for determining the regional stress tensor using earthquake focal mechanism data: Application to the San Fernando earthquake sequence[J]. Journal of Geophysical Research Solid Earth, 1984, 89(B11): 9305-9320.
[24] Michale A J. Determination of stress from slip data: Fault and folds[J]. Journal of Geophysical Research Solid Earth, 1984, 89(B13): 11517-11526.
[25] Michale A J. Use of focal mechanisms to determine stress: A control study[J]. Journal of Geophysical Research Solid Earth, 1987, 92(B1): 357-368.
[26] Hardebeck J L, Michale A J. Damped regional-scale stress inversions: Methodology and examples for southern California and the Coalinga aftershock sequence[J]. Journal of Geophysical Research Solid Earth, 2006, 111(B11): B11310.
[27] 罗艳, 赵里, 曾祥方, 等. 芦山地震序列震源机制及其构造应力场空间变化[J]. 中国科学: 地球科学, 2015, 45(4): 538-550.
LUO Yan, ZHAO Li, ZENG Xiang-fang, et al. Focal mechanisms of the Lushan earthquake sequence and spatial variation of the stress field[J]. Science China: Earth Sciences, 2015, 45(4): 538-550 (in Chinese).
[28] 罗艳, 赵里, 田建慧. 2008年8月30日攀枝花M_S6.1地震序列深度及震源区应力特征[J]. 中国科学: 地球科学, 2020, 50(3): 404-417.
LUO Yan, ZHAO Li, TIAN Jian-hui. The focal depths of the 2008 Panzhihua earthquake sequence and stress field in the source region[J]. Science China: Earth Sciences, 2020, 50(3): 404-417 (in Chinese).
[29] 李峰, 龚飞, 刘华国, 等. 重庆市都市区活断层探测与地震危险性评价[Z]. 国家科技成果, 2011.
LI Feng, GONG Fei, LIU Hua-guo, et al. Active fault detection and seismic risk assessment in Chongqing metropolitan area[Z]. National scientific and technological achieve, 2011 (in Chinese).
[30] 吴朋, 苏金蓉, 黄春梅, 等. 四川宜宾地区S波分裂特征[J]. 中国地震, 2017, 33(3): 414-423.
WU Peng, SU Jin-rong, HUANG Chun-mei, et al. Characteristic of shear-wave splitting in the Yibin area, Sichuan Province[J]. Earthquake Research in China, 2017, 33(3): 414-423 (in Chinese).
[31] Luo J, Zhao C P, LÜ J, et al. Characteristics of focal mechanisms and stress field in the Southeastern Margin of the Tibetan Plateau[J]. Pure and Applied Geophysics, 2016, 173(8): 2687-2710.
[32] Xu Y, Herrmann R B, Koper K D. Source parameters of regional small-to-moderate earthquakes in the Yunnan-Sichuan region of China[J]. Bulletin of the Seismological Society America, 2010, 100(5B): 2518-2531.
[33] 崔子健. 区域构造应力场的反演与地震带划分的研究[D]. 中国地震局地球物理研究所, 2018.
CUI Zi-jian. Study on the inversion of regional tectonic stress field and the devisionof seismic belt[D]. Institute of Geophysics, China Earthquake Administration, 2018 (in Chinese).
[34] 陈安国, 高原, 石玉涛. 龙门山断裂带域上地壳各向异性及其变化[J]. 地球物理学报, 2019, 62(8): 2959-2981.
CHEN An-guo, GAO Yuan, SHI Yu-tao. Seismic anisotropy and its variation in the upper crust beneath the Longmen Shan fault zone[J]. Chinese Journal of Geophysics, 2019, 62(8): 2959-2981 (in Chinese).
[35] Zheng T, Ding Z F, Ning J Y, et al. Crustal azimuthal anisotropy beneath the southeastern Tibetan Plateau and its geodynamic implications[J]. Journal of Geophysical Research Solid Earth, 2018, 123(11): 9733-9749.
[36] 石玉涛, 高原, 张永久, 等. 松潘—甘孜地块东部、川滇地块北部与四川盆地西部的地壳剪切波分裂[J]. 地球物理学报, 2013, 56(2): 481-494.
SHI Yu-tao, GAO Yuan, ZHANG Yong-jiu, et al. Shear-wave splitting in the crust in eastern Songpan-Garzê block, Sichuan-Yunnan block and western Sichuan basin[J]. Chinese Journal of Geophysics, 2013, 56(2): 481-494 (in Chinese).
[37] Zhao B, Huang Y, Zhang C H, et al. Crustal deformation on the Chinese mainland during 1998—2014 based on GPS data[J]. Geodesy and Geodynamics, 2015, 6(1): 7-15.
[38] 谢富仁, 陈群策, 崔效锋, 等. 中国大陆地壳应力环境基础数据库[J]. 地球物理学进展, 2007, 22(1): 131-136.
XIE Fu-ren, CHEN Qun-ce, CUI Xiao-feng, et al. Fundamental database of crustal stress environment in continental China[J]. Progress in Geophysics, 2007, 22(1): 131-136 (in Chinese).
[39] Wessel P, Smith W H F. New, improved version of the generic mapping tools released[J]. EOS, Transactions American Geophysical Union, 1998, 79: 579.