InSAR数据约束的2021年5月21日云南漾濞M_(S)6.4地震发震构造研究  

Seismogenic structure of the Yangbi,Yunnan M_(S)6.4 earthquake on May 21,2021 constrained by InSAR data

作　　者：于书媛[1,2] 骆佳骥 杨源源[1,2] 李成龙 YU Shuyuan;LUO Jiaji;YANG Yuanyuan;LI Chenglong(Anhui Earthquake Agency, Hefei 230031, Anhui, China;Mengcheng National Geophysical Observatory, Bozhou 233527, Anhui, China;State Key Laboratory of Earthquake Dynamics, Institute of Geology, CEA, Beijing 100029, China)

机构地区：[1]安徽省地震局,安徽合肥230031 [2]安徽蒙城地球物理国家野外科学观测研究站,安徽亳州233527 [3]中国地震局地质研究所,地震动力学国家重点实验室,北京100029

出　　处：《地震工程学报》2021年第4期777-783,790,共8页China Earthquake Engineering Journal

基　　金：国家自然科学基金项目(41802224);中国地震局监测、预报、科研三结合课题(SJH-202001041);安徽省地震局重点基金课题(20210501)。

摘　　要：运用Sentinel-1A卫星数据和D-InSAR技术,获取2021-05-21云南漾濞M_(S)6.4地震的同震形变场。结果显示,漾濞地震同震形变场长轴近NW展布升降轨形变场符号相反,视线向最大沉降量和抬升量为0.1 m。InSAR同震形变场反演的滑动分布主要集中在沿走向2~12 km,倾向1~9 km的范围内,最大滑动量0.35 m,发震断层长9.8 km、宽4 km,滑动量主要集中在地下3~6 km范围内,滑动角-146.7°。同震位移场及滑动分布模型反映本次地震为发震断层的右旋走滑事件,地震破裂未达到地表。断层模型反演结果显示,矩震级为MW6.1,发震断层以北西走向右旋走滑运动为主,初步认为本次MW6.1地震发震断裂可能是一条NW向的维西—乔后断裂西侧的隐伏次生断裂。The coseismic deformation field of 2021-05-21 Yangbi M_(S)6.4 earthquake in Yunnan Province was obtained by using Sentinel-1A satellite data and D-InSAR technology.The results showed that the coseismic deformation field of the Yangbi earthquake is distributed along the long axis near NW,and the signals of ascending and descending deformation are opposite.The maximum slip along line of sight is 0.1 m.Slips are mainly distributed in 2-12 km along strike and 1-9 km along down-dip direction,and the maximum displacement is 0.35 m.The seismic rupture is 9.8 km long and 4 km wide.The slip focus on the range of 3-6 km underground,and the slip angle is-146.7°.The coseismic deformation field and slip distribution model implied that the earthquake is a right-lateral strike-slip event,with rupture not reaching the surface.The inversion results of fault model showed that the moment magnitude of the mainshock is MW6.1,and the seismogenic structure is a NW-trending right-lateral strike-slip fault.It is inferred that the seismogenic structure of the 2021 Yangbi MW6.1 earthquake is a NW-trending blind secondary fault on the west side of Weixi-Qiaohou fault.

关 键 词：2021漾濞MW6.1地震 同震形变 INSAR 右旋走滑 震源机制 

分 类 号：P315.725[天文地球—地震学]