利用InSAR技术研究2018年西藏谢通门MW5.6地震发震构造

Seismogenic Structure of 2018 Xietongmen,Tibet MW5.6 Earthquake Inferred from InSAR Data

2018年12月24日在西藏日喀则市谢通门县发生MW5.6地震。利用Sentinel-1A卫星数据和D-InSAR技术,获得该地震LOS方向的同震形变场图像,并以此为约束反演地震断层的几何参数和同震滑动分布特征。反演结果表明,谢通门MW5.6地震发震断层近南北走向,断面倾向西,倾角约35°,破裂长度约12 km,同震滑动主要集中在4~11 km深度范围内,以正断倾滑为主,最大滑动量0.18 m,矩震级MW5.6。2018年谢通门地震发震构造是谢通门—申扎伸展断裂系中的一条新生盲断层。

On December 24,2018,a MW5.6 earthquake occurred in Xietongmen County,Shigatse City,Tibet.This study utilizes Sentinel-1A satellite SAR data and D-InSAR technology to obtain an image of the co-seismic deformation field in the LOS direction and then inverses the geometric parameters and co-seismic slip distribution of the seismological fault of the event.The results show that the fault associated with the MW5.6 earthquake lies in a near NS-direction,has a dip angle of 35°,and a rupture length of 12 km.The co-seismic slip is mainly concentrated in a range of 4-11 km,the maximum slip is 0.18 m,and the moment magnitude is MW5.6.In addition,it is determined that the seismogenic fault of the Xietongmen earthquake in 2018 is a new blind fault belonging to the Xietongmen—Shenzha extensional fault system.