基于三维剩余密度结构的松原地震成因  

GENESIS OF SONGYUAN EARTHQUAKES BASED ON 3D RESIDUAL DENSITY STRUCTURE

作　　者：刘文玉[1,4,5] 程正璞 年秀清 陈闫 胡钰铃[4] 覃祖建 邵明正 LIU Wen-yu;CHENG Zheng-pu;NIAN Xiu-qing;CHEN Yan;HU Yu-ling;QIN Zu-jian;SHAO Ming-zheng(College of Geoexploration Science and Technology,Jilin University,Changchun 130026,China;Center for Hydrogeology and Environmental Geology Survey,CGS,Tianjin 300309,China;School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China;School of Geophysics and Measurement-control Technology,East China University of Technology,Nanchang 330000,China;Engineering Research Center for Seismic Disaster Prevention and Engineering Geological Disaster Detection of Jiangxi Province,Nanchang 330013,China)

机构地区：[1]吉林大学,地球探测科学与技术学院,长春130026 [2]中国地质调查局水文地质环境地质调查中心,天津300309 [3]中国科学技术大学,地球和空间科学学院,合肥230026 [4]东华理工大学,地球物理与测绘技术学院,南昌330000 [5]江西省防震减灾与工程地质灾害探测工程研究中心,南昌330013

出　　处：《地震地质》2024年第2期462-476,共15页Seismology and Geology

基　　金：江西省防震减灾与工程地质灾害探测工程研究中心开放基金(1410600024);基于松原地区三维地壳电性结构研究项目(1410001022)共同资助。

摘　　要：自2006年以来松原市乾安县与宁江区地震频发,成为东北地震活动最为频繁的区域,目前对两地的发震构造和地震成因的认识存在严重分歧,制约了地震危险性评价与预防工作的开展。文中通过对区域重力数据进行非线性共轭梯度聚焦反演,获得了松原震区的三维剩余密度结构,结合石油井震资料,获得了如下认识:1)研究区的剩余密度异常呈高低相间的带状分布,南部异常走向为NNW,北部异常转变为NNE向,该特征反映出乾安震区和宁江震区的深部孕震环境不同,前者震源位于查干花高密度异常体内及其边缘,后者震源位于松原低密度异常带中部,指示两地震源位置的岩性不同;2)两者的发震构造不相同,前者受控于查干花断裂和乾安断裂,后者受控于松原断裂和扶余北断裂;3)地震的形成与区域应力,基底结构,深部气、流体运移和长期油气开采等因素有关。长期注水采油破坏了地质结构和应力环境,可能是重要的地震诱发因素。Since 2006,more than 10 earthquakes with the magnitude of 4 or higher have occurred continuously in Ningjiang district and Qian an county,Songyuan city of Jilin province,with tens of thousands of aftershocks.The largest earthquake is the magnitude 5.8 earthquake on November 23,2013 in Qiangorlos Mongolian autonomous county,Songyuan city,Jilin province.Frequent earthquake activities not only cause a large number of damaged buildings,but also trigger geological disasters such as sand liquefaction and slope instability,which have attracted widespread attention from the public and government departments.In order to comprehensively understand the causes of earthquakes in the Songyuan area,much studies on earthquake anomalies,seismogenic structures,and source depths have benn conducted recently.However,there are still some difference opinions in understanding the causes of earthquakes in the Songyuan area,for example,the major different viewpoints include:1)it is caused by the regional stress release caused by Pacific subduction,mainly based on the consistency between the stress field in the source area and the background stress field of the Pacific plate subducting towards the edge of the east Asian continent;2)it is related to deep melt or fluid migration,mainly based on the existence of low-speed and low resistance anomalous bodies in the deep part of the seismic area;3)it is related to long-term oil and gas extraction,the main basis is that the seismic source spectrum exhibits characteristics of early and fast attenuation compared to typical structural earthquakes,and the time-domain and frequency-domain characteristic parameters such as waveform complexity and spectral ratio are also significantly different from typical structural earthquakes.In addition,the seismic source mechanism contains a large number of nondual force source components and shallow seismic source depth.Moreover,there is also significant controversy over the seismogenic structure,with the focus on whether the Qian an and Ningjiang earthquake re

关 键 词：松原地震 三维剩余密度结构 深部孕震环境 基底构造 地震成因 

分 类 号：P315.2[天文地球—地震学] P315.726[天文地球—固体地球物理学]