2022年1月8日青海门源M_(S)6.9地震的同震地表破裂特征  

SURFACE RUPTURE CHARACTERISTICS OF THE MENYUAN M_(S)6.9 EARTHQUAKE ON JANUARY 8,2022,QINGHAI PROVINCE

作　　者：梁宽 何仲太 姜文亮[1] 李永生 刘泽民 LIANG Kuan;HE Zhong-tai;JIANG Wen-liang;LI Yong-sheng;LIU Ze-min(National Institute of Natural Hazards,Ministry of Emergency Management of China,Beijing 100085,China;Hebei Key Laboratory of Earthquake Dynamics,Institute of Disaster Prevention,Sanhe,Hebei 065201,China;Key Laboratory of Crustal Dynamics,China Earthquake Administration,Beijing 100085,China)

机构地区：[1]应急管理部国家自然灾害防治研究院,北京100085 [2]防灾科技学院,河北省地震动力学重点实验室,三河065201 [3]中国地震局地壳动力学重点实验室,北京100085

出　　处：《地震地质》2022年第1期256-278,共23页Seismology and Geology

基　　金：应急管理部国家自然灾害防治研究院基本科研业务专项(ZDJ2019-28,ZDJ2019-21);国家自然科学基金(41872227,41602221);高分遥感地震监测与应急应用示范系统(二期)川滇地区高分活动构造与风险排查示范项目(31-Y30F09-9001-20/22-6)共同资助。

摘　　要：2022年1月8日1时45分,青海省海北藏族自治州门源县发生M_(S)6.9地震,震中(37.77°N,101.26°E)位于祁连-海原断裂带冷龙岭断裂的西段,震源深度为10km。地震发生后,通过解译高分7号卫星的震后影像,快速确定了同震地表破裂带的主体破裂区位置,并第一时间进入震中现场开展野外地表破裂调查工作,获取同震地表破裂带精确分布位置、破裂长度、破裂特征、同震位错量等关键信息。根据震后遥感影像解译和现场调查结果可知,此次门源M_(S)6.9地震的地表破裂带由位于NWW向冷龙岭断裂西段和近EW向托莱山断裂东端的2段破裂带组成,走向分别为291°和86.9°,延伸长度分别约为26km和3.5km。地表破裂主要是由张裂隙、张剪裂隙、挤压鼓包和震陷等多类型破裂呈雁列状组合而成,总体以左旋走滑运动为主,局部兼有逆冲性质,最大同震左旋位错为2.77m。综合高分辨率遥感影像解译、现场调查、InSAR反演的震源机制和断层破裂模型、余震精定位等结果,确定门源M_(S)6.9地震发生于托莱山断裂与冷龙岭断裂在深部的交会位置,主要发震构造是冷龙岭断裂的西段(走向为112°,倾角为88°),其西侧的托莱山断裂东端同时发生破裂。1986年M_(S)6.4地震、2016年M_(S)6.4地震以及2022年M_(S)6.9地震皆发生于冷龙岭断裂的西段,短时间内发生的3次6级以上强震,说明该地区仍为应力和形变积累区域,仍具有发生特大地震的潜在风险。At 1:45 on January 8,2022,a M_(S)6.9 earthquake occurred in Menyuan County,Haibei Prefecture,Qinghai Province.The epicenter(37.77°N,101.26°E)is located in the western segment of the Lenglongling Fault of the Qilian-Haiyuan fault zone,with a focal depth of 10km.The earthquake is located in the northwest of the M_(S)6.4 Menyuan earthquake on January 21,2016.According to the survey results of China Earthquake Administration,the highest intensity of this earthquake is IX degree,and the long axis of the isoseismic line is NWW-striking.The earthquake caused serious damage to the Daliang Tunnel between Haomen Station and Junmachang Station,and the Lanxin high-speed railway was interrupted.After the earthquake,the distribution of the earthquake surface rupture zone was quickly determined by interpreting the GF-7 satellite post-earthquake images,and the field surface rupture investigation was carried out at the epicenter site in the first time.The field investigation mainly includes the identification of surface rupture zones,the investigation of rupture characteristics,the survey of fault geomorphology,the high-precision aerial photogrammetry of typical rupture points,the identification and measurement of coseismic dislocation,and the investigation of earthquake disasters.Aerial photogrammetry realizes real-time difference through UAV linked network RTK,and takes high-definition photos from multiple angles.Pix4D software is used to complete calculation and point cloud encryption,etc.DSM(Digital Surface Model)and DOM(Digital Orthophoto Map)are generated for surface rupture space reproduction and feature measurement and analysis.According to the interpretation of high-resolution remote sensing images by GF-7 satellite and field investigation,the surface rupture of M_(S)6.9 Menyuan earthquake can be divided into NW-striking western segment of Lenglongling Fault and EW-striking eastern segment of Tuolaishan Fault.The two surface ruptures are 291°and 86.9°,respectively,and their lengths are not less than 26km and 3.5km re

关 键 词：2022年1月8日青海门源M_(S)6.9地震 地表破裂带 发震构造 冷龙岭断裂 托莱山断裂 

分 类 号：P315.2[天文地球—地震学]