联合地震位错模型和ESISTEM方法提取地震同震三维形变场  

Extracting Coseismic Three-Dimensional Deformation Field of Earthquake by Integrating Earthquake Dislocation Model and ESISTEM Method

作　　者：刘洋[1,2,3] 李航昊 熊露雲 温扬茂 杨九元[1] LIU Yang;LI Hanghao;XIONG Luyun;WEN Yangmao;YANG Jiuyuan(School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China;Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,Wuhan University,Wuhan 430079,China;Key Laboratory of Geophysical Geodesy,Ministry of Natural Resources,Wuhan University,Wuhan 430079,China)

机构地区：[1]武汉大学测绘学院,湖北武汉430079 [2]武汉大学地球空间环境与大地测量教育部重点实验室,湖北武汉430079 [3]自然资源部地球物理大地测量重点实验室,湖北武汉430079

出　　处：《武汉大学学报（信息科学版）》2023年第3期349-358,395,共11页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41874011,41974004);国家重点研发计划(2018YFC1503603)。

摘　　要：高精度同震三维形变场对于研究地震变形模式、震源机制等具有重要意义。设计并实现了一种联合地震位错模型和扩展融合大地测量、卫星形变观测、应变张量估计(extended simultaneous and integrated strain tensor estimation from geodetic and satellite deformation measurements, ESISTEM)方法的新方法,以2021年Ms 6.4漾濞地震为例,利用哨兵1号A、B星(Sentinel-1A/B)升、降轨影像获得该地震的合成孔径雷达干涉测量形变场,利用地震位错模型正演得到的南北向形变分量进行约束,成功提取了该地震完整的同震三维形变场及应变场。结果表明,漾濞地震断层西南侧主要向西、向北运动,最大形变分别为4.8 cm、9.5 cm;东北侧主要向东、向南运动,最大形变分别为7.4 cm、4.6 cm;垂直向抬升、沉降的最大值分别为3.6 cm、3.4 cm;发震断层以右旋走滑运动为主,兼有少量正断分量;发震断层区域受到显著的膨胀、剪切和旋转作用。Objectives: High-precision coseismic three-dimensional(3D) deformation field is of great significance for investigating the earthquake deformation pattern and focal mechanism. For the 2021 Ms 6.4 Yangbi earthquake, the characteristics of coseismic deformation observation can be described as:(1) Only two directions of interferometric synthetic aperture radar(InSAR) line of sight observations from the ascending and descending tracks;(2) lack of azimuth observation;(3) some incoherent regions existed around the epicenter;(4) sparse and unevenly distributed GNSS observation. This observational fact makes it difficult to accurately extract its coseismic 3D deformation field. Therefore, a new method is investigated to solve this issue.Methods: The new method is designed and implemented by integrating earthquake dislocation model and extended simultaneous and integrated strain tensor estimation from geodetic and satellite deformation measurements(ESISTEM) method. Firstly, the InSAR deformation field of the 2021 Ms 6.4 Yangbi earthquake is obtained by using the ascending and descending Sentinel-1A/B images. Secondly, the northsouth deformation component obtained from the forward modeling of earthquake dislocation model is used as a constraint. Finally, with the new method, the complete coseismic 3D deformation field and strain field of the earthquake are successfully extracted.Results:(1) The 3D coseismic deformation field indicates that the southwest side of the Yangbi earthquake fault mainly moves westward and northward, with maxima of 4.8 cm and 9.5 cm, respectively. The northeast side mainly moves eastward and southward, with maxima of 7.4 cm and 4.6 cm, respectively. The maxima of vertical uplift and subsidence are 3.6 cm and 3.4 cm, respectively.(2) The earthquake fault is dominated by the right-lateral strike-slip movement with a small amount of normal components.(3) The strain field indicates that the earthquake fault area experiences significant expansion,shear,and rotation.Conclusions:The new method can make us

关 键 词：漾濞地震 地震位错模型 ESISTEM方法 三维形变场 应变场 

分 类 号：P237[天文地球—摄影测量与遥感]