荣县地震InSAR同震与时间序列形变初步分析

借助Sentinel-1A卫星升降轨数据,利用合成孔径雷达差分干涉测量(DInSAR)和Okada均匀滑动模型反演获得四川荣县地区三维同震形变场及荣县地震震源参数。结果表明,此次地震造成的断裂现象大体沿NS向,两侧沉降区域中间伴随抬升现象,最大垂直形变量约18 mm;荣县地震发震断层符合逆断层特性,断层长约9.5 km,宽约2.1 km。采用时间序列分析技术获取该地区2018-11~2019-03各时间段的累计形变,结果发现,该区域在震前形变波动较小,地震是造成累计形变较大的主要原因,震后地表变化趋于稳定。

Preliminary Analysis of InSAR Coseismic and Time Series Deformation of Rongxian Earthquake

Abstract: In this paper, by exploiting Sentinel-1A satellite ascending and descending data, we obtain a three-dimensional coseismic deformation field and source parameters by using synthetic aperture radar differential interferometry(DInSAR) and Okada uniform sliding model inversion. The results show that the fault slip caused by this earthquake is generally along the north-south direction, and the uplift occurs in the middle of the subsidence area on both sides, with the maximum vertical deformation around 18 mm. The seismogenic fault parameters of the Rongxian earthquake accords with the characteristics of the reverse fault, having length of about 9.5 km and width of about 2.1 km. The accumulative deformation in the study area from 2018-11 to 2019-03 is obtained using time series analysis technique. The results suggest that the deformation fluctuation in this area is stable before and after the earthquake, and the earthquakes are the main reason for the large accumulative deformation in the area.