南北地震带地壳S波分裂参数的空间分布与构造意义

南北地震带是青藏、华南、华北等一级块体构造边界汇聚的区域，中国大陆最活跃的地震活动带。项目研究区包含青藏高原东北缘、东缘和东南缘，内有多种典型地质构造现象，区域深部构造、介质变形及其与地震活动的关系尚未弄清。项目拟收集、整理和使用数千个地震台站资料，采用近场地震记录的S波分裂分析方法，开展南北地震带上地壳各向异性空间分布形态与构造意义研究。项目将获得南北地震带上地壳地震各向异性全域分布图像，在此基础上讨论不同类型的断裂、造山带、构造单元内部与构造边界的上地壳各向异性分布形态的构造指示意义，分析与识别结构诱发各向异性与应力诱发各向异性，成像基于S波分裂资料约束的主压应力方向空间分布，探讨上地壳介质变形，探索S波分裂参数分布、变化及其地震活动的关联性。项目研究结果可为区域深部构造、物质运移、动力学模拟等研究领域提供重要约束和参考。

The North-South seismic zone is the convergent tectonic boundary of the first-order blocks, such as the Tibetan plateau block, the South China block and the North China block, as well as the most active seismic zone within Chinese mainland. There geologically are various typical tectonic phenomena in the study area, where are distributed with the northeast margin, the east margin and the southeast margin of Tibetan plateau. It is not clear that the regional deep tectonics, the medium deformation and their connections to seismicity. This study tries to collect, sort and use the seismic data of thousands of seismic stations. With the S-wave splitting analysis on local seismic records, it will investigate the spatial distribution of seismic anisotropy in the upper crust and its tectonic implications in the North-South seismic zone. This project will image the spatial distribution of seismic anisotropy in the upper crust in the study area. It will discuss the characteristics of seismic anisotropy and the significances to tectonics in the areas of the different types of faults and orogenic belts, as well as the interior and the boundary of tectonic units. This project also study the recognitions on the structure-induced anisotropy and stress-induced anisotropy, image the spatial distribution of principal compressive stress direction based on the S-wave splitting data, discuss the deformation of the upper crust, explore the distribution and the variations of the S-wave splitting parameters, and their connections to seismicity. The results of this project could provide with anisotropic constraints and references to the studies of the regional deep tectonics, material migration and dynamic simulation.