青藏高原东缘及周边区域岩石圈各向异性和变形特征研究

项目名称： 青藏高原东缘及周边区域岩石圈各向异性和变形特征研究

项目编号： No.41274093

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 沈旭章

作者单位： 中国地震局兰州地震研究所

项目金额： 80万元

中文摘要： 青藏高原隆升机制研究中存在争议的一个焦点问题就是关于高原及其周边区域岩石圈的变形方式，这一问题是回答青藏高原隆升及地壳缩短过程中物质流向何处的关键。岩石圈各向异性的空间分布特征是岩石圈变形最重要的参数。由于接收函数对界面附近介质参数的变化及各向异性的分层特征较为敏感，而SKS波对介质内部平均各向异性较为敏感，因此二者具有互补优势。本申请充分利用这种优势，在已进行的数值试验基础上，拟研究远震接收函数和SKS横波分裂联合反演岩石圈变形特征参数的方法。并将该方法应用于青藏高原东缘及周边300多个宽频带固定台站和我们已经布设的高密度台阵资料，重点研究该区域岩石圈各向异性的深度分布特征，据此构建地震台站下方合理的岩石圈变形模型。

中文关键词： 青藏高原东北缘；接收函数；各向异性；近邻反演；地震波影区

英文摘要： The deformation of the lithosphere of Tibet and its adjacent is the focus of the study of the Tibet uplift, which is also the key to answer the questions-how does the Tibet uplift and where have the material produced by the crust shortenning go. The most important parameter of the deformation of lithosphere is the distribution of anisotropy in different depth. The receiver function is sensitive to the contrast of the velocity structure around the discontinuity or the depth characteristic of the anisotropy, while the SKS splitting is sensitive to the average anisotropy. So these two methods are complementary. Based on the numerical tests, we plan to invert the lithospheric anisotropic structure with neighbourhood algorithm method. The tele-seismic receiver functions and SKS splitting will be used to invert the lithospheric structure beneath more than 300 permanent stations and dense seismic array in the eastern margin of Tibet and its adjacent area. The depth characteristic of the lithospheric anisotropy will be given important consideration, then the reliable model of the lithosphere deforamtion will be constructed.

英文关键词： Northeast margin of Tibetan Plateau；Receiver function；Anisotropy；Neighboring inversion；Seismic wave shadow zone