九寨沟M_S7.0级地震三维同震形变场提取

Extraction of 3D coseismic deformation field of Jiuzhaigou Ms7.0 earthquake

针对D-InSAR地震形变监测中存在LOS(line of sight)视线向模糊的问题,该文构建了一种融合升降轨不同视线向干涉测量数据获取三维同震形变场的方法。以2017年九寨沟M_S7.0级地震为例,基于研究区的Sentine1_1A数据和SRTM(1″)DEM数据,采用二轨差分的D-InSAR技术,融合升降轨LOS向以及自定义视线向的干涉测量数据进行联合解算,获取了研究区三维同震形变场,解决了单一轨道雷达LOS提取结果不能准确反映地表三维形变场的问题。实验表明,此次地震造成了震中附近一定范围地表的沉降和东南向的滑移,并通过震区形变剖面图和形变等值线图,分析了形变场的空间分布以及此次地震所造成地表断裂的位置,认为此次地震与塔藏断裂、虎牙断裂存在关联性,其运动形式为主动盘逆冲的走滑型地震。

According to the problems of line-of-sight LOS(LOS)blurring in D-InSAR seismic deformation monitoring,this paper proposes a new method that acquiring three-dimensional coseismic deformation field from interferometric data with different lines of sight from the elevating rail.By using the two-track differential D-InSAR technique based on the Sentine1_1Adata and the SRTM(1″)DEM data in the study area,this strategy presents a way of fusing the ascending and descending orbit measurement data from different line of sight to deal with the problem that the LOS extraction results of a single-orbit radar could not accurately reflect the three-dimensional deformation field on the surface.The experiment results show that the earthquake caused a certain range of surface subsidence and southeastward slip near the epicenter.Through the seismic section deformation profile and deformation contour map,the spatial distribution of the deformation field and the surface caused by the earthquake were analyzed.It is considered that the earthquakes are related to the fault of the Tazang and the Huya fault and the motion is in the form of a strike-slip earthquake with active plate thrust.