基于图像特征的接收函数各向异性反演研究

项目名称： 基于图像特征的接收函数各向异性反演研究

项目编号： No.41474036

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 王卫民

作者单位： 中国科学院青藏高原研究所

项目金额： 110万元

中文摘要： 近年来基于横向各向同性（TI）介质假设通过接收函数反演获取地壳内的各向异性结构的方法得到了快速发展，它能够获得台站下不同深度的地壳分层速度结构、各向异性强度以及对称轴方向、倾角等各向异性参数，这是层析成像和剪切波分裂等各向异性研究方法所欠缺的。本项目拟通过把接收函数从传统的多道记录转换为时间-方位域的二维图像，研究利用小波变换优异的时-频局域化特征和多分辨分析能力，在压制干扰和噪声的基础上，将接收函数响应的主要特征用少量的数据集表示，在此基础上构建非线性反演目标函数，开展基于二维图像特征的非线性反演研究，实现利用接收函数高效可靠地获取地壳各向异性结构的目的。本项目将基于新发展的反演技术，利用接收函数响应研究青藏高原东北部地壳内部各向异性结构，为研究区壳幔形变、块体间相互作用及圈层耦合关系等提供地震学依据和约束。

中文关键词： 各向异性；接收函数；非线性反演；图像特征提取；小波变换

英文摘要： Under the conditions of TI medium, study of anisotropic structure in crustal inversed from receiver function has been rapid development in recent years. The method can be applied to study regions with complex anisotropic feature, from which we can constrain the lateral and depth distribution of anisotropy, as well as other important parameters, including the depth of crustal velocity discontinuity, the magnitudes of anisotropy , the orientation of symmetry axis and tilt of symmetry axis. The methods of anisotropic tomography and shear-wave split lack the ability to obtain such more anisotropic parameter. The project intends to convert the receiver function from the traditional multi-channel recording to a two-dimensional image of the time and back- azimuth domain. In the case, a small data set which contains main features and eliminate the noise of receiver function caused by anisotropy, can be extracted by wavelet transform with excellent - frequency localization features and multi-resolution analysis capabilities. And then the inverse objective function constructed by the small data set.The new inverse technique based on image feature will be developed to obtain anisotropy parameters from receiver function efficiently and reliably. The newly developed inversion method will used to obtain crustal anisotropic structure of the northeastern Tibetan Plateau by receiver function response, that provides the basis and constraints for the study of crust and mantle deformation, the blocks and spheres coupling interactions.

英文关键词： Anisotropy;receiver function;nonlinear inverse;image characteristics extraction;Wavelet transform