地震破裂模型约束的中国阿里地震三维形变场

利用环境卫星（Environmental Satellite，Envisat）的升、降轨数据在地震破裂模型约束下获取2007年阿里地震的高质量同震地表三维形变场。首先，对合成孔径雷达（synthetic aperture radar，SAR）影像进行差分干涉处理，得到地震造成的视线向同震地表形变场；然后，以地震破裂模型为约束条件，采用赫尔默特方差分量估计法来解算阿里地震的高质量地表三维同震形变场。结果表明，震中区域最大下沉达约4.7 cm，东西向位移较小，南北向呈挤压趋势。总体上，三维形变的特征表明阿里地震是一个以正倾滑为主兼少量右旋走滑运动的地震事件。

Three-Dimensional Deformation Field of Ali Earthquake from InSAR Observations and Earthquake Rupture Model

In this study, we construct high-quality three-dimensional coseismic surface deformation field of the 2007 Ali earthquake using ascending and descending SAR data acquired from Envisat sate-llite with constraint of earthquake rupture model. Firstly, we use two-pass differential interferometry to generate line-of-sight coseismic surface deformation field of the earthquake from two pairs of SAR images. Then, with constraint of three components of displacement derived from the earthquake rupture model, we obtain the high-quality three-dimensional coseismic surface deformation field using Helmert variance component estimation method. The results show that the subsidence caused by the event is about 4.7 cm in the epicenter, where east-west displacement is small and the epicentral area is under north-south compression. We also calculate quasi east-west and quasi north-south displacements only with InSAR observations, whose patterns of deformation distribution are consistent with the results constrained by USGS earthquake rupture model. Finally, the characteristics of the three-dimensional deformation field indicate that the event is dominated by normal motion with slightly right-lateral strike-slip component.