2022年泸定M_(S)6.8地震发震断裂的浅表结构  

Shallow Surface Structure of Seismogenic Fault of Luding,Sichuan M_(S)6.8 Earthquake in 2022

作　　者：郑荣荧 余中元 陈柏旭 李路伟 杨堰琳 赵钱 游嘉靖 ZHENG Rongying;YU Zhongyuan;CHEN Baixu;LI Luwei;YANG Yanlin;ZHAO Qian;YOU Jiajing(Bejing Disaster Prevention Technology Co.Ltd.,Beijing 101100,China;Institute of Disaster Prevention,Sanhe 065201,China)

机构地区：[1]北京防灾科技有限公司,北京101100 [2]防灾科技学院,河北三河065201

出　　处：《防灾科技学院学报》2022年第4期67-74,共8页Journal of Institute of Disaster Prevention

基　　金：北京防灾科技有限公司研发专项(FZKJYF202201);国家重点研发计划(2019QZKK0901)。

摘　　要：鲜水河断裂磨西段于2022年9月5日发生M_(S)6.8地震,并于10月22日发生M_(S)5.0余震。深入研究该地震发震构造的浅表结构对于分析其强震破裂与传播特征及该地区未来的强震活动趋势具有重要意义。通过高密度电法勘探、无人机高分辨率遥感解译、大比例尺地质地貌填图与地表调查等方法,结合泸定M_(S)6.8地震同震变形特征,对鲜水河断裂磨西段的浅表结构特征开展了研究。鲜水河断裂磨西段平面上包括多个分支,主断裂产状近直立,各次级断裂兼具正断、逆冲性质,断裂破碎带宽度约130m。泸定M_(S)6.8地震中,鲜水河断裂磨西段沿线同震变形特征明显,多处可见地表垂直断错、逆冲隆起和左旋位错。研究表明,2022年泸定M_(S)6.8地震发震断裂的浅表结构整体表现为“陡倾角、多分支、电性差异明显、基岩破碎且物性差异大”的复杂特征,这种浅表结构的特殊性可能直接影响着此次强震的同震地表破裂过程。An M_(S)6.8 Earthquake occurred on Sep.5,2022,and an M_(S)5.0 aftershock followed on Oct.22 in the Moxi section of the Xianshuihe River Fault Zone.It is of great significance to study the shallow surface structure of the seismogenic structure of Luding M_(S)6.8 Earthquake for analyzing its rupture process and the future strong earthquake activity trend in the study region.In this paper,using the high-density electrical prospecting,the UAV high-resolution remote sensing interpretation,the largescale geological and geomorphological mapping and surface survey,and then combining with the co-seismic deformation characteristics of the Luding M_(S)6.8 Earthquake,we studied the shallow surface structural characteristic of the Moxi section of the Xianshuihe River Fault Zone.The results show that the west section of Xianshuihe River Fault Zone consists of several branches on the plane,the main fault is nearly vertical,and each secondary fault has both normal and thrust properties.The width of the fault fracture zone is about 130m.The co-seismic deformation along the Moxi section of the Xianshuihe River Fault Zone is obvious,and there are many vertical faulting,thrust uplift and left-handed dislocation.The shallow surface structure of the seismogenic fault of the Luding M_(S)6.8 Earthquake in 2022 shows a complex characteristic of"steep dip angle,multiple branches,obvious electrical differences,broken bedrock and large physical differences",which may have directly affected the co-seismic surface rupture process of the strong earthquake.

关 键 词：泸定M_(S)6.8地震 高密度电法勘探 鲜水河断裂 浅表结构特征 

分 类 号：P315.2[天文地球—地震学]