| 2020年龙泉山断裂带MS5.1地震成因综合分析 |
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| 引用本文： | 柳存喜,黎莎,刘冠男.2020年龙泉山断裂带MS5.1地震成因综合分析[J].西北地震学报,2021,43(2):306-315,330. |
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| 作者姓名： | 柳存喜 黎莎 刘冠男 |
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| 作者单位： | 雅砻江流域水电开发有限公司, 四川 成都 610051;中国电建集团贵阳勘测设计研究院有限公司, 贵州 贵阳 550081;成都理工大学地球物理学院, 四川 成都 610059;数学地质四川省重点实验室(成都理工大学), 四川 成都 610059 |
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| 基金项目： | 数学地质四川省重点实验室开放基金资助课题（scsxdz2020yb03）；雅砻江流域水库地震监测专项（YLDC-DBA-2020003） |
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| 摘 要： | 2020年2月3日四川省成都市青白江区发生MS5.1地震,震中烈度为Ⅵ度。该地震事件震中位于龙泉山断裂带上,距离成都市中心38 km,是龙泉山断裂带历史上非常罕见的5.0级以上地震事件。针对该事件成因进行了综合分析与研究,具体内容包括:(1)通过收集历史地震资料讨论龙泉山断裂带的地震活动性;(2)利用高质量的波形数据对主震位置进行重定位;(3)根据地震层析成像获得的三维vP、vS以及泊松比(σ)模型分析了孕震构造和流体影响,以及(4)利用固体潮理论模型分析了固体潮与地震触发的相关性。结果表明,本次MS5.1地震发生在龙泉山断裂带北段,震中坐标为(30.732°N,104.529°E),震源深度为15.12 km;震源位于高-低泊松比过渡带附近,并伴随着大范围的低速异常,初步推断与深部流体有关;同时,固体潮在断层面上产生的剪切应力变化,也可能与本次地震的触发密切相关,暗示着在地震发生前龙泉山北段的地震危险性已经达到了较高水平。因此深部流体侵入作用、强震同震效应以及特定孕震构造环境的综合影响可能是导致本次地震触发的主要因素。
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| 关 键 词： | 龙泉山断裂带 地震成因 地震层析成像 |
| 收稿时间： | 2020/7/22 0:00:00 |
Comprehensive Analysis of Seismogenesis of the 2020 MS5.1 Earthquake on the Longquanshan Fault Zone, SW China |
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| LIU Cunxi,LI Sh,LIU Guannan.Comprehensive Analysis of Seismogenesis of the 2020 MS5.1 Earthquake on the Longquanshan Fault Zone, SW China[J].Northwestern Seismological Journal,2021,43(2):306-315,330. |
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| Authors: | LIU Cunxi LI Sh LIU Guannan |
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| Institution: | Yalong River Hydropower Development Company, Ltd., Chengdu 610051, Sichuan, China;Guiyang Engineering Corporation Limited of Power China, Guiyang 550081, Guizhou, China; College of Geophysics, Chengdu University of Technology, Chengdu 610059, Sichuan, China;Geomathematics Key Laboratory of Sichuan Province(Chengdu University of Technology), Chengdu 610059, Sichuan, China |
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| Abstract: | On Feb 3,2020,an MS5.1 earthquake occurred in Chengdu,Sichuan Province.The epicenter of the earthquake event is located on the Longquanshan fault zone,38 km away from the center of Chengdu.As a rare earthquake event with M≥5.0 in the history of Longquanshan fault zone,a comprehensive analysis was carried out on the seismogenesis of this event:(1)The seismicity along the Longquanshan fault zone was discussed by collecting historical seismic data;(2)the location of main earthquake was relocated by using high-quality waveform data;(3)the seismogenic structure and fluid influence were analyzed through seismic tomography;(4)the relationship between the earth tide and the earthquake was analyzed by using the theoretical model of earth tide.The results showed that the MS5.1 earthquake occurred in the northern part of Longquanshan fault zone with epicenter coordinate of(30.732°N,104.529°E)and focal depth of 15.12 km.The source is located near the transition zone of high-low Poisson's ratio,accompanied by a wide range of low velocity anomalies.Furthermore,the change of shear stress caused by the earth tide on the fault plane is also considered to be closely related to the triggering of the earthquake,which indicates that the seismic risk of the northern part of Longquanshan fault zone has reached a high level before the earthquake.This study suggests that the deep fluid intrusion,the coseismic effect of strong earthquakes,and the comprehensive influence of specific seismogenic and tectonic environment may be the main factors leading to the triggering of this earthquake. |
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| Keywords: | Longquanshan fault zone seismogenesis seismic tomography |
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