基于Sentinel-1A的2021年双湖M_(W)5.7地震同震破裂模型  

Coseismic Rupture Model of the 2021 Shuanghu M_(W)5.7 Earthquake Based on Sentinel-1A

作　　者：夏涛 刘小利 余鹏飞 邓德贝尔 乐子扬 高天琪 XIA Tao;LIU Xiaoli;YU Pengfei;DENG Debeier;YUE Ziyang;GAO Tianqi(Key Laboratory of Earthquake Geodesy,CEA,40 Hongshance Road,Wuhan 430071,China;Institute of Disaster Prevention,465 Xueyuan Street,Sanhe 065201,China)

机构地区：[1]中国地震局地震大地测量重点实验室,武汉市430071 [2]防灾科技学院,河北省三河市065201

出　　处：《大地测量与地球动力学》2022年第5期533-540,共8页Journal of Geodesy and Geodynamics

基　　金：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(IS20176155);国家自然科学基金(4207417);中国地震局地震科技星火计划(XH22003C)。

摘　　要：利用Sentinel-1A SAR数据提取2021年西藏双湖县M_(W)5.7地震同震形变场及2.5D形变场,反演断层滑动分布模型。计算不同节面解为接收断层产生的库仑应力变化差异确定发震构造,并结合余震分布信息评估未来地震风险性。结果表明,地震震中为34.37°N、87.71°E,震源深度6.51 km,发震断层倾向东、走向33°、倾角50°、平均滑动角-74°,以倾滑为主兼有少量左旋走滑分量,最大滑动量0.26 m。短时间内,震区南部地震风险较小,北部则需要结合更多资料进一步分析。本次地震是在羌塘块体持续向东扩张的背景下,受EW向拉伸作用使得黄水湖正断层发生的一次弥散型变形活动,SN向地堑得到进一步扩张。We employ Sentinel-1A SAR data to extract the coseismic deformation field and 2.5D deformation field of the 2021 Shuanghu,Tibet M_(W)5.7 earthquake for further inversion to obtain the fault slip distribution model.The seismogenic structure is determined by calculating the difference of Coulomb stress changes caused by different nodal solutions for receiving faults,and combining the aftershocks distribution to evaluate the future seismic risk.The results show that the epicenter is 34.37°N,87.71°E,the focal depth is 6.51 km,and the seismogenic fault tends to the east,strike is 33°,dip is 50°,and average slip angle is-74°.There is a small amount of sinistral strike-slip component;the maximum slip is 0.26 m.In a short period,the seismic risk in the southern part of the earthquake area is relatively small,but the seismic risk in the northern part needs to be further analyzed with more data.The 2021 Shuanghu earthquake is a dispersive deformation on the Huangshuihu normal fault,resulting from the continuous EW-direction extension of the Qiangtang block,and the SN-direction graben in Huangshuihu is further expanded.

关 键 词：INSAR 羌塘块体 双湖地震 地堑扩张 滑动分布反演 

分 类 号：P228[天文地球—大地测量学与测量工程] P313[天文地球—测绘科学与技术]