Sentinel-1 SAR数据约束的2018年谢通门M_(W)5.8地震同震破裂模型  

Coseismic Rupture Model of the 2018 Xaitongmoin M_(W)5.8 Earthquake Constrained by Sentinel-1 SAR Data

作　　者：倪乙鹏 聂兆生[1] 熊维[1] 陈威[1] 余鹏飞[1] NI Yipeng;NIE Zhaosheng;XIONG Wei;CHEN Wei;YU Pengfei(Institute of Seismology,CEA,40 Hongshance Road,Wuhan 430071,China)

机构地区：[1]中国地震局地震研究所,武汉市430071

出　　处：《大地测量与地球动力学》2021年第6期589-594,共6页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金(42074015,42074007);中国地震局地震研究所和应急管理部国家自然灾害防治研究院基本科研业务费专项(IS2018126282)。

摘　　要：通过Sentinel-1卫星升降轨数据获取谢通门地震的同震形变场,并基于均匀弹性半无限位错模型反演地震的同震滑动分布模型。InSAR同震形变场表明,升降轨视线向最大形变量分别为0.049 m和0.051 m,形变场长轴大致呈南北方向,位于甲岗-定结断裂西侧。通过对倾角和倾向进行格网搜索发现,西倾节面更可能为该地震的发震节面。反演结果表明,滑动分布主要位于2~10 km深度范围内,平均滑动量为0.02 m,最大滑动量为0.10 m,发震断层倾角为47°,平均滑动角为-81.60°,显示该地震以正倾滑动为主。大地测量数据约束的该地震震中为30.27°N、87.75°E,震源深度为6.58 km,释放地震矩为5.056×10^(17) Nm,对应矩震级为MW5.7,与GCMT、USGS公布的震级基本一致。综合分析震中位置和滑动机制认为,甲岗-定结断裂的分支断层为本次谢通门地震的发震断层。We use Sentinel-1 satellite data to obtain the coseismic deformation field of the Xaitongmoin earthquake,and invert the coseismic slip distribution model based on the homogeneous elastic half-space model.The coseismic deformation field derived from InSAR shows that the maximum deformation in the LOS direction of the ascending and descending tracks are 0.049 m and 0.051 m respectively.The long axis of the deformation field is roughly in the NW direction,which is located in the west side of Jaggang-Dinggye fault.The west dip nodal plane is more likely to be the seismogenic nodal plane through the grid search of dip and inclination.The results show that the slip distribution is mainly located within the depth range of 2-10 km,with an average slip of 0.02 m and maximum slip of 0.10 m.The dip angle of seismogenic fault is 47°and the average rake angle is-81.60°,which indicates that the earthquake is mainly normal dip slip.The epicenter of the earthquake constrained by geodetic data is 30.27°N,87.75°E,with focal depth of 6.58 km and the moment released about 5.056×10^(17) Nm,corresponding to a magnitude of MW5.7,which is consistent with that from USGS and GCMT.Based on the epicenter location and the slip mechanism of this earthquake,we infer that the branch fault of Jaggang-Dinggye fault is seismogenic.

关 键 词：INSAR 谢通门地震 甲岗-定结断层 同震形变 滑动分布反演 发震断层 

分 类 号：P315[天文地球—地震学] P228[天文地球—固体地球物理学]