2020年2月18日长清MS4.1地震发震构造研究

doi:10.12196/j.issn.1000-3274.2022.01.008

摘要/Abstract

摘要： 本文利用基于波形互相关的双差定位方法对2020年2月18日长清M_S4.1地震序列进行了精定位计算, 共得到33个地震事件的精定位结果。结果显示, 地震序列主要沿NW向分布, 在水平方向上具有自NW向SE迁移, 在深度上具有由浅向深迁移的特征; 序列震源深度主要集中在2~7 km, 其中, 主震的震源深度约2.8 km。由于长清地震序列的地震数量较少, 为了更准确地了解长清地震序列的发震构造、探索该序列的发生和发展过程, 本文采用CAP方法反演了主震的震源机制解, 其中, 节面Ⅰ走向223°、倾角42°、滑动角-160°, 节面Ⅱ走向117.9°、倾角76.8°、滑动角-49.8°, 最佳拟合震源矩心深度约2.8 km, 矩震级M_W4.2。结合区域构造特征分析认为, 长清M_S4.1地震的发震断裂为孝里铺断裂和东阿断裂之间发育的一条浅层次生断裂。在ENE向区域应力场作用下, 发震断裂产生高角度正断滑动, 并伴有左旋走滑分量, 从而引发长清地震序列。

关键词: 双差定位, CAP方法, 震源机制解, 发震构造, 2020年长清M_S4.1地震

Abstract: The Changqing M_S4.1 earthquake and its aftershocks have been precisely relocated by the double-difference earthquake location method in this paper, and the accurate locations of 33 events have been obtained. The results show that the earthquakes are mainly distributed along the NW direction, with the characteristics of migrating from NW to SE in the horizontal direction and from shallow to deep in depth direction. The focal depth are mainly concentrated in 2~7 km, and the main shock is about 2.8 km depth. In order to more accurately understand the seismogenic structure, we also inverted the focal mechanism of the M_S4.1 earthquake with the “Cut and Paste” (CAP) method. The best double couple solution of the mainshock shows that the best-fit moment magnitude and focal depth are M_W4.2 and 2.8 km respectively. Nodal plane Ⅰ of the focal mechanism is 223°, 42° and -160° for strike, dip and rake angle respectively, while Nodal plane Ⅱ is 117.9°, 76.8° and -49.8°. According to the distribution of earthquakes and the focal mechanism, combining with the regional structural characteristics, it suggests that the seismogenic fault of the Changqing M_S4.1 earthquake is a shallow secondary fault developed between the xiaolipu fault and the dong’a fault. Under the action of regional stress field in ENE direction, the seismogenic fault produce a high angle, normal-slip with left strike-slip dislocation which lead to the Changqing M_S4.1 earthquake and its aftershocks.

Key words: Double-difference location, CAP method, Focal mechanism, Seismogenic structure, 2020 Changqing M_S4.1 earthquake

中图分类号:

P315.7

戴宗辉, 李冬梅, 王鹏, 郑建常, 王志才, 李霞. 2020年2月18日长清M_S4.1地震发震构造研究[J]. 地震, 2022, 42(1): 111-121.

DAI Zong-hui, LI Dong-mei, WANG Peng, ZHENG Jian-chang, WANG Zhi-cai, LI Xia. Study on the Seismotectonics of the M_S4.1 Changqing Earthquake on 18 February, 2020[J]. EARTHQUAKE, 2022, 42(1): 111-121.

参考文献

[1] 晁洪太, 王锜, 李家灵, 等. 山东省地震构造图、山东省新构造图及说明书(1∶100万)[M]. 济南: 山东省地图出版社, 1997.
CHAO Hong-tai, WANG Qi, LI Jia-ling, et al. Seismotectonic map of Shandong province, neotectonics map of Shandong province and their instructions (1∶1 million)[M]. Jinan: Shandong Map Publishing House, 1997 (in Chinese).
[2] 薄克庭, 蔡有兄. 长清-孝里铺水文地质单元岩溶地下水资源量计算及开采潜力分析[J]. 山东国土资源, 2015, 31(12): 37-42.
BO Ke-ting, CAI You-xiong. Calculation of karst groundwater resources and analysis on exploitation potentiality of Changqing-Xiaolipu hydrogeologic unit[J]. Shandong Land and Resources, 2015, 31(12): 37-42 (in Chinese).
[3] 刘晨. 济南主城区及附近地震活动性分析[D]. 济南: 山东大学, 2011.
LIU Chen. Seismicity analysis in Jinan city[D]. Jinan: Shandong University, 2011 (in Chinese).
[4] 赵桂兰. 长清地区岩溶水系统功能研究[D]. 济南: 济南大学, 2012.
ZHAO Gui-lan. Study on Function of Karst Water System in Chang Qing Area[D]. Jinan: Graduate Jinan University, 2012 (in Chinese).
[5] 郑建常, 李冬梅, 王鹏. 2013年莱州M4.6地震序列震源机制与发震构造初探[J]. 地震地质, 2015, 37(2): 384-399.
ZHENG Jian-chang, LI Dong-mei, WANG Peng. A Preliminary discussion on the focal mechanism and seismic tectonic feature of the 2013 Laizhou M4.6 earthquake sequence[J]. Seismology and Geology, 2015, 37(2): 384-399 (in Chinese).
[6] 王未来, 吴建平, 房立华, 等. 2014年云南鲁甸M_S6.5地震序列的双差定位[J]. 地球物理学报, 2014, 57(9): 3042-3051.
WANG Wei-lai, WU Jian-ping, FANG Li-hua, et al. Double difference location of the Ludian M_S6.5 earthquake sequences in Yunnan province in 2014[J]. Chinese Journal of Geophysics, 2014, 57(9): 3042-3051 (in Chinese).
[7] 曲均浩, 蒋海昆, 李金, 等. 2013—2014年山东乳山地震序列发震构造初探[J]. 地球物理学报, 2015, 58(6): 1954-1962.
QU Jun-hao, JIANG Hai-kun, LI Jin, et al. Preliminary study for seismogenic structure of the Rushan earthquake sequence in 2013—2014[J]. Chinese Journal of Geophysics, 2015, 58(6): 1954-1962 (in Chinese).
[8] Waldhauser F, Ellsworth W L. A double-difference earthquake location algorithm: Method and application to the Northern Hayward Fault, California[J]. Bulletin of the Seismological Society of America, 2000, 90(6): 1353-1368.
[9] Waldhauser F, Ellsworth W L. Fault structure and mechanics of the Hayward Fault, California, from double-difference earthquake locations[J]. Journal of Geophysical Research, 2002, 107(B3): ESE3-1-EAE3-15.
[10] 吕坚, 苏金蓉, 靳玉科, 等. 汶川8.0级地震序列重新定位及其发震构造初探[J]. 地震地质, 2008, 30(4): 917-925.
LÜ Jian, SU Jin-rong, JIN Yu-ke, et al. Discussion relocation and seismo-tectonics of the M_S8.0 Wenchuan earthquake sequences[J]. Seismology and Geology, 2008, 30(4): 917-925 (in Chinese).
[11] 房立华, 吴建平, 王长在, 等. 2012年新疆新源M_S6.6地震余震序列精定位研究[J]. 中国科学: 地球科学, 2013, 43(12): 1929-1933.
FANG Li-hua, WU Jian-ping, WANG Chang-zai, et al. Relocation of the 2012 M_S6.6 Xinjiang Xinyuan earthquake sequence[J]. Science China: Earth Sciences, 2013, 43(12): 1929-1933 (in Chinese).
[12] 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. Relocation and focal mechanism of the Songyuan earthquake swarm sequence in 2013[J]. Earthquake, 2018, 38(4): 62-73 (in Chinese).
[13] 王小娜, 叶秀薇, 黄元敏, 等. 2018年11月26日台湾海峡M_S6.2地震发震构造研究[J]. 地球物理学报, 2019, 62(12): 4673-4683.
WANG Xiao-na, YE Xiu-wei, HUANG Yuan-min, et al. Seismogenic structure of the M_S6.2 Taiwan strait earthquake on 26 November, 2018[J]. Chinese Journal of Geophysics, 2019, 62(12): 4673-4683 (in Chinese).
[14] 张天中, 武巴特尔, 黄媛, 等. 近台资料对近震相对定位算法的影响[J]. 地球物理学报, 2007, 50(4): 1123-1130.
ZHANG Tian-zhong, WU Bater, HUANG Yuan, et al. Effect of the data recorded at nearby stations on earthquake relative location[J]. Chinese Journal of Geophysics, 2007, 50(4): 1123-1130 (in Chinese).
[15] 张碧秀, 汤永安, 夏铁军, 等. 聊城—荣城地壳二维速度结构初探“泰山震”之谜[J]. 中国地震, 1996, 12(2): 141-146.
ZHANG Bi-xiu, TANG Yong-an, XIA Tie-jun, et al. The crustal velocity structure of Liaocheng—Rongcheng: Making an inquiry into “Taishan earthquake”[J]. Earthquake Research in China, 1996, 12(12): 141-146 (in Chinese).
[16] 李霞, 刘希强, 李亚军, 等. 山东及邻区地震的重新定位及其与活动构造的关系[J]. 中国地震, 2012, 28(4): 381-392.
LI Xia, LIU Xi-qiang, LI Ya-jun, et al. Relocation of earthquakes in Shandong and its neighboring areas in China and relationship between their tectonics[J]. Earthquake Research in China, 28(4): 381-392 (in Chinese).
[17] Zhao L S, Helmberger D V. Source estimation from broadband regional seismograms[J]. Bulletin of the Seismological Society of American, 1994, 84(1): 91-104.
[18] Zhu L P, Helmberger D V. Advancement in source estimation techniques using broadband regional seismograms[J]. Bulletin of the Seismological Society of America, 1996, 86(5): 1634-1641.
[19] 韩立波, 蒋长胜, 包丰. 2010年河南太康M_S4.6地震序列震源参数的精确确定[J]. 地球物理学报, 2012, 55(9): 2973-2981.
HAN Li-bo, JIANG Chang-sheng, BAO Feng. Source parameter determination of 2010 Taikang M_S4.6 earthquake sequences[J]. Chinese Journal of Geophysics, 2012, 55(9): 2973-2981 (in Chinese).
[20] 张广伟, 雷建设, 梁姗姗, 等. 2014年8月3日云南鲁甸M_S6.5级地震序列重定位与震源机制研究[J]. 地球物理学报, 2014, 57(9): 3018-3027.
ZHANG Guang-wei, LEI Jian-she, LIANG Shan-shan, et al. Relocations and focal mechanism solutions of the 3 August 2014 Ludian, Yunnan M_S6.5 earthquake sequence[J]. Chinese Journal of Geophysics, 2014, 57(9): 3018-3027 (in Chinese).
[21] 易桂喜, 龙锋, 梁明剑, 等. 2017年8月8日九寨沟M7.0地震及余震震源机制解与发震构造分析[J]. 地球物理学报, 2017, 60(10): 4083-4097.
YI Gui-xi, LONG Feng, LIANG Ming-jian, et al. Focal mechanism solutions and seismogenic structure of the 8 August 2017 M7.0 Jiuzhaigou earthquake and its aftershocks, northern Sichuan[J]. Chinese Journal of Geophysics, 2017, 60(10): 4083-4097 (in Chinese).
[22] 刘建明, 王琼, 李金, 等. 2016年12月8日呼图壁M_S6.2地震序列重定位与发震构造[J]. 地震地质, 2018, 40(3): 566-578.
LIU Jian-ming, WANG Qiong, LI Jin, et al. Relocation of the Hutubi M_S6.2 earthquake sequence on 8 December 2016 and analysis of the seismogenic structure[J]. Seismology and Geology, 2018, 40(3): 566-578 (in Chinese).
[23] 黄浩, 付虹. 2015年11月23日祁连5.2级地震发震构造初步研究[J]. 地震, 2019, 39(1): 114-125.
HUANG Hao, FU Hong. A preliminary study of the seismogenic structure of the Nov.23, 2015 Qilian 5.2 earthquake[J]. Earthquake, 2019, 39(1): 114-125 (in Chinese).
[24] Zhu L P, Helmberger D V. Advancement in source estimation techniques using broadband regional seismograms[J]. Bulletin of the Seismological Society of America, 1996, 86(5): 1634-1641.
[25] Wells D L, Coppersmith K J. New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement[J]. Bulletin of the Seismological Society of America, 1994, 84(4): 974-1002.
[26] 郑建常, 王鹏, 李冬梅, 等. 使用小震震源机制解研究山东地区背景应力场[J]. 地震学报, 2013, 35(6): 773-784.
ZHENG Jian-chang, WANG Peng, LI Dong-mei, et al. Tectonic stress field in Shandong region inferred from small earthquake focal mechanism solutions[J]. Acta Seismologica Sinica, 2013, 35(6): 773-784 (in Chinese).
[27] 周翠英, 王铮铮, 蒋海昆, 等. 华东地区现代地壳应力场及地震断层错动性质[J]. 地震地质, 2005, 27(2): 273-288.
ZHOU Cui-ying, WANG Zheng-zheng, JIANG Hai-kun, et al. Contemporary crustal stress field and feature of earthquake fault slip in east China[J]. Seismology and Geology, 2005, 27(2): 273-288 (in Chinese).
[28] 丰成君, 张鹏, 戚帮申, 等. 郯庐断裂带附近地壳浅层现今构造应力场[J]. 现代地质, 2017, 31(1): 46-70.
FENG Cheng-jun, ZHANG Peng, QI Bang-shen, et al. Recent tectonic stress field at the shallow Earth’s crust near the Tan-Lu fault zone[J]. Geoscience, 2017, 31(1): 46-70 (in Chinese).
[29] 谭成轩, 胡秋韵, 张鹏, 等. 日本M_W9.0级大地震前后华北和东北地区现今构造应力作用调整过程与研究意义探讨[J]. 地学前缘, 2015, 22(1): 345-359.
TAN Cheng-xuan, HU Qiu-yun, ZHANG Peng, et al. Present tectonic stress adjustment process before and after Japan M_W9.0 earthquake in north and northeast China and its research significance[J]. Earth Science Frontiers, 2015, 22(1): 345-359 (in Chinese).