基于InSAR的2022年四川泸定地震同震形变与震源模型  

Coseismic Deformation and Source Model of the 2022 Sichuan Luding Earthquake under InSAR Data Constraints

作　　者：白希选 湛舒文 张兵强 郭爱智 边晓亚 陈疆丞 BAI Xi-xuan;ZHAN Shu-wen;ZHANG Bing-qiang;GUO Ai-zhi;BIAN Xiao-ya;CHEN Jiang-cheng(School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China;Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,China)

机构地区：[1]武汉工程大学土木工程与建筑学院,武汉430074 [2]中国科学院精密测量科学与技术创新研究院,武汉430077

出　　处：《科学技术与工程》2024年第21期8853-8860,共8页Science Technology and Engineering

基　　金：国家自然科学基金(41704081,41901235);武汉工程大学研究生教育创新基金(CX2022169)。

摘　　要：2022年9月5日,四川甘孜州泸定县发生M_(S) 6.8级地震。基于合成孔径雷达差分干涉测量(differential interferometric synthetic aperture radar,D-InSAR)技术处理Sentinel-1A卫星升降轨数据得到此次地震的同震形变场,之后基于DEM拟合以大气延迟为主的噪声分布模型并对整个形变场进行观测误差校正,得出升降轨地表最大形变分别达到13 cm和13.5 cm。以InSAR同震形变场为约束,基于弹性半空间位错模型,反演得出此次地震的断层几何参数和同震滑动分布,并基于滑动分布计算出震中附近空间区域库伦应力变化。滑动分布结果表明,此次地震是一次左旋走滑地震,主要滑动集中在深度为2~12 km的范围内,最大滑动量为2.25 m,发生在主断层面深度约为5.8 km处。库伦应力变化结果显示,在鲜水河断裂及安宁河断裂有应力增加,应注意后期强震风险。On September 5,2022,an M_(S) 6.8 magnitude earthquake occurred in Luding County,Ganzi Prefecture,Sichuan.Based on differential interferometric synthetic aperture radar(D-InSAR)technology,the data of the Sentinel-1A satellite s ascent and descent orbit were processed to obtain the coseismic deformation field of this earthquake.Then,a noise distribution model dominated by atmospheric delay was fitted using DEM and the entire deformation field was corrected for observation errors.The maximum surface deformation of the ascent orbit reached 13 cm and 13.5 cm,respectively.Based on the InSAR co-seismic deformation field as a constraint and an elastic half space dislocation model,the geometric parameters of the fault and co-seismic slip distribution of this earthquake were inverted,and the Coulomb stress changes in the spatial area near the epicenter were calculated based on the slip distribution.The sliding distribution results indicate that this earthquake is a sinistral strike slip earthquake,with the main sliding concentrated in the depth range of 2~12 km,with a maximum sliding amount of 2.25 m,occurring at a depth of approximately 5.8 km on the main fault plane.The results of Coulomb stress changes show that there is an increase in stress in the Xianshui River and Anning River faults,and attention should be paid to the risk of strong earthquakes in the later stage.

关 键 词：INSAR 同震形变 震源参数 泸定地震 

分 类 号：P315[天文地球—地震学]