利用升降轨Sentinel-1A影像提取2017年九寨沟M_(s) 7.0地震同震形变场

Extracting Co-seismic Deformation of the 2017 Jiuzhaigou M_(s) 7.0 Earthquake Based on the Ascending and Descending Sentinel-1A Image

2017年8月8日,四川省阿坝州九寨沟县发生M_(s) 7.0地震。其诱发因子主要是巴颜喀拉板块强烈运动,使得青藏高原板块向东运动,把能量从塔藏断裂释放出来,导致了地震的发生。由于九寨沟景区内植被密度大,地形复杂,给常规的测量方法提取形变场造成了很大的困难。因此,利用D-InSAR(interferometric synthetic aperture radar)技术,采用欧空局Sentinel-1A升降轨SAR影像,分别对升降轨影像对进行数据处理,并对结果进行交叉验证分析,从而获取了九寨沟地震的较为精确同震形变场。结果表明:形变场的分布呈不规则的“核仁型”,长约24 km,宽约29 km,呈现出由西北向东南的走向。视线(line of sight,LOS)向形变的极值分别为降轨11.2 cm、升轨22.4 cm,形变量级较大。

On August 8,2017,a M_(s) 7.0 earthquake occurred on Jiuzhaigou County,Aba Prefecture,Sichuan Province.The Jiuzhaigou earthquake was mainly caused by the strong movement of the Bayanhar plate,which made the Tibetan Plateau moved eastward and released the energy from the Tazang fault.Due to the high-density of vegetation and the complex terrain in Jiuzhaigou scenic area,it was very difficult to extract the deformation field by conventional measuring methods.The ascending and descending deformation were extracted from the European Space Agency Sentinel-1A images based on D-InSAR(interferometric synthetic aperture radar)technology,and the results were analyzed as cross.The results show that the distribution of the deformation field was an irregular“nucleolar type”with the length of 24 km and the width of 29 km,and a trend from northwest to southeast.The extreme values of the descending and ascending deformation in the direction of the line of sight(LOS)were respectively 11.2 cm and 22.4 cm.