基于Sentinel-1数据的银川盆地现今地壳形变研究

基于InSAR技术，利用Sentinel-1数据获取银川盆地及周边地区2015~2019年高空间分辨率地壳形变速率场。结果显示，银川盆地整体呈下沉趋势，贺兰山东麓断裂及黄河断裂两条主控断裂两侧存在较明显的差异性运动，芦花台隐伏断裂和银川隐伏断裂活动不明显。对一般倾角断层的震间地表形变曲线拟合公式进行改进，实现了基于单一轨道InSAR观测值同时反演断层倾角、走滑速率、倾滑速率以及闭锁深度。将算法应用于灵武断裂的活动状态及闭锁深度反演，得到断裂走滑速率约为303 mm/a，正断倾滑速率约为027 mm/a，闭锁深度约为6.8 km，倾角约为54.7°。此外，InSAR监测发现，石嘴山市和银川市东部存在局部巨幅形变，通过InSAR时序分析及现场调查认为，形变可能由人类活动引起。

Current Crustal Deformation of Yinchuan Basin Based on Sentinel-1 Data

Yinchuan basin is located in the north part of the North-South seismic belt, with strong historical earthquakes and active small earthquakes. Based on InSAR technology, we use Sentinel-1 data to obtain the high spatial resolution crustal deformation rate field of Yinchuan basin and its surrounding areas between 2015 to 2019. The result shows that the whole Yinchuan basin is in a sinking trend, and there are obvious differential movements on both sides of the Helanshan eastern piedmont fault and the Yellow river fault, while the activities of Luhuatai buried fault and Yinchuan buried fault are not obvious. In this paper, the fitting formula of the surface deformation curve between earthquakes is improved, so that the inversion of fault dip, strike slip rate, dip slip rate and locking depth can be realized based on the observation value of single orbit InSAR. The algorithm is applied to the inversion of Lingwu fault activity state and locked depth, and the result shows that the strike slip rate is about 3.03 mm/a, the positive dip slip rate is about 0.27 mm/a, the locked depth is about 6.8 km, and the dip angle is about 54.7°. In addition, InSAR monitoring found large local deformation in Shizuishan and Yinchuan. After InSAR time series analysis and field investigation, we infer the deformation may be caused by human activities.