川滇块体南部壳幔岩石圈三维精细速度结构与分层各向异性研究

川滇块体南部是全球构造运动和岩石圈变形最活跃的地区之一，是研究青藏高原隆升、变形和演化的重要窗口。但对于形成该地区低地形梯度、大规模的地表运动以及众多地质作用和岩石圈变形的方向转变的动力学过程及变形机制尚有争议，是地球动力学研究的热点。三维精细速度结构和地震波分层各向异性的研究是探讨地球内部构造特征、岩石圈变形和演化的重要手段。本项目基于国家固定台网、喜马拉雅一期台阵和申请人已经和拟将布设的34个流动台，采用背景噪声伴随成像中互相关经验格林函数对三维模型下的波形拟合，获取地壳和上地幔顶部三维瑞雷面波精细速度结构和壳幔岩石圈分层各向异性；联合接收函数计算的地壳平均各向异性，估计该地区各向异性在深度上的分布。结合地质学、地球运动学等研究成果，深入探讨川滇块体南部岩石圈结构、壳幔耦合状态和岩石圈变形及演化的动力学机制。本研究对进一步认识青藏高原形成机制和变形演化的动力学过程具有重要的科学意义。

The southern Chuandian Block is one of the regions with intense deformation and most active intra-continent seismicity in the Earth. It is the best region in studying the mechanisms for the buildup and evolution of the Tibetan plateau. Currently, the deformation mechanisms and the tectonic processes forming this low-gradient plateau margin, large-scale surface deformation and the rotation of geological process remain controversial. It is the a hot spot in geodynamics research. As a proxy of lithospheric deformation, the 3D fine velocity structure and layered anisotropy can be used to uncover the tectonic characteristics of the Earth and the mechanisms of continental lithospheric deformation and evolution. Therefore, We apply ambient noise adjoint tomography and receiver function analysis technique to develop a 3D refine Rayleigh wave velocity model and layered seismic anisotropy based on the large amount and high quality waveform data recorded by the seismic networks of the China Earthquake Administration and our temporary stations. Combined with the results from geology, geophysics and geodynamics, we will build a 3D structure of the southern Chuandian block to study lithospheric structure, the state of the crust-mantle coupling and the mechanism of the lithospheric deformation. This project will provide important insights on the mechanism of the formation and deformation evolution of the Tibetan Plateau.