2021年海地Mw 7.2地震震源机制与同震滑动分布研究  

Investigation of Focal Mechanism and Coseismic Slip Distribution for Haiti Mw 7.2 Earthquake in 2021

作　　者：于仪 李雪[1,2] 陈威 李承涛[1,2] 孙振 YU Yi;LI Xue;CHEN Wei;LI Chengtao;SUN Zhen(Institute of Seismology,China Earthquake Administration,Wuhan 430071,China;Key Laboratory of Seismogeodesy,China Earthquake Administration,Wuhan 430071,China;College of Oceanography and Space Informatics,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国地震局地震研究所,湖北武汉430071 [2]中国地震局地震大地测量重点实验室,湖北武汉430071 [3]中国石油大学(华东)海洋与空间信息学院,山东青岛266580

出　　处：《武汉大学学报（信息科学版）》2024年第12期2232-2240,共9页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41401428)。

摘　　要：2021年8月14日,海地发生了Mw 7.2地震。为研究此次海地地震同震形变及其震源机制,根据Sentinel-1A卫星提供的升降轨数据,利用合成孔径雷达差分干涉(differential interferometric synthetic aperture radar,DInSAR)技术获取了海地地震的同震形变场。采用均匀采样方法对观测数据进行降采样,根据均匀弹性半空间位错模型,反演了地震断层的精确几何参数和发震断层的最优滑动分布模型,结果表明,此次地震是一次逆冲兼左旋走滑型地震事件,最优断层倾角为58°,走向为265.5°,滑动角为50°,震中位置为73.60°W,18.43°N,最大滑动量为3.2 m。以反演的同震滑动模型来正演,获取震源区3个方向的位移分量且投影到卫星视线向,获取研究区域雷达视线向的形变场,发现海地同震形变以隆升为主,最大的隆升量为64 cm,是主震和余震共同作用的结果。Objectives:For investigating the crustal deformation and its focal mechanism caused by the 2021 Haiti Mw 7.2 earthquake,the coseismic deformation field of Haiti earthquake is obtained with dif-ferential interferometric synthetic aperture radar technology according to the ascending and descending orbit data provided by Sentinel-1A satellite.Methods:First,the observations are downsampled using uniform sampling methods.Then,fault parameters and optimal sliding distribution model are inversed using the Okada uniform elastic semi-infinite dislocation model.Finally,the displacements in three directions are cal-culated by the linear inversion data according to the forward model.The displacements in east,north,and up directions are projected to the line of sight(LOS)of the satellite,thereby acquiring the deformation field of the radar LOS in the experiment area.Results:The results show that this earthquake is a thrust and left-lateral strike-slip event.The optimal fault dip angle is determined 58°,the strike is 265.5°,and the slip angle is 50°.The epicenter location is 73.60°W,18.43°N,and the maximum sliding amount is 3.2 m.Con⁃clusions:The deformation of the earthquake is mainly uplift,and its value is 64 cm,which is the result of the combined action of the main shock and aftershocks.

关 键 词：合成孔径雷达差分干涉 海地地震 同震形变场 同震滑动分布模型 震源机制 

分 类 号：P237[天文地球—摄影测量与遥感] P315[天文地球—测绘科学与技术]