宽幅InSAR资料约束下的崩错-东巧共轭走滑断裂系现今运动机制研究

Research on the slip kinematics of the Bengco-Dongqiao conjugate strike-slip fault system, located in the central Tibetan Plateau, is important for understanding the outward growth of the Tibet. There is rare study focused on this before. We plan to apply and develop a technology named Wide-scan Sententinel-1 IW to work on this question. We try to analyze an overall deformation pattern for this conjugate strike-slip fault system. Besides, a set of the Sentinel-1 Interferometric Wide SAR data will be processed to achieve their Wide-scan InSAR time series results and also produce the error correction algorithm. The followings are our works: (1) We will use the principle of full rank matrix to improve the density and the stability of the coherent points, (2) The network method and high resolution ECMWF data assisted for atmospheric delay error correction, (3) the closed-phase loop method for correcting unwrapping phase error and, (4) The joint model was used to separate the long wave signal of fault deformation from orbit error. Finally, combined with GPS data, we will analysis the whole motion characteristics of conjugate strike-slip faults，investigate the strain accumulation of tectonic deformation in time and space. It is helpful to understand the characteristics of a series of conjugate strike slip faults developed in the middle part of the Qinghai Tibet Plateau

崩错-东巧共轭断裂带是青藏高原中部一系列共轭走滑断裂系的重要组成部分，目前对该共轭走滑断裂带运动学调节机制的研究相对较少。因此本申请选择崩错-东巧共轭走滑断裂系为研究对象，应用最新的Sentinel-1 IW 宽幅SAR数据，通过构建宽幅InSAR时序分析流程框架和误差校正算法，旨在提高宽幅InSAR对微小形变信息的提取精度。方法包括：1)以满秩矩阵原则提高相干点密度和信号稳定性; 2)利用小基线网络法和高分辨ECMWF大气数据辅助下校正宽幅干涉图中大气延迟误差; 3)闭合残差方法校正离散点相位解缠误差；4)利用联合解算模型分离长波长断裂形变信号与轨道误差信号。最终获取整个崩错-东巧共轭走滑断裂带的构造形变特征，并联合GPS资料分析崩错-东巧共轭走滑断裂系整体运动机制，研究该共轭走滑断裂系在时间和空间上的应变调节问题，有助于理解青藏高原中部发育的一系列共轭走滑断裂系的运动特征。

分布在拉萨地块和羌塘地块之间的众多V字型共轭走滑断裂系是青藏高原向东运动的主要调节构造。崩错-东巧共轭断裂系是一个具有代表性的，其构造环境的确定是了解西藏中部V形共轭走滑断裂系动力机制的基础性问题。本文利用Sentinel-1卫星三年的升降轨、SAR资料，研究了崩错-东巧共轭断层的变形速率。仅使用时间基线较长的干涉图来增加变形信号的比例。在大空间覆盖的Sentinel-1数据中，采用大气延迟误差校正和InSAR叠加策略来减小各种误差。InSAR结果表明，沿崩错断层东段和西段的断层平行变形速度分别为5±1mm/yr和2.5±1mm/yr。水平应变率结果表明，累积应变集中在崩错断裂东段和谷露裂谷。速度场和应变速率场表明，安多-蓬错断裂可能与崩错断裂配对形成新的共轭体系，并在崩错断裂和谷露裂谷之间发生构造转换。这些结果可以更好地解释崩错-东巧共轭断裂系的构造变形环境，并为整个高原内部的地壳动力学研究提供依据。