初至波层析成像的反演参数选取：以南海中央次海盆三维地震探测数据为例  

The selection of optimal inversion parameters for first-arrival seismic tomography: An application to 3D seismic data from the central sub-basin of the South China Sea

作　　者：王建[1,2] 赵明辉[1] 贺恩远[1,2] 张佳政[1] 丘学林[1] 

机构地区：[1]中国科学院边缘海地质重点实验室,中国科学院南海海洋研究所,广东广州510301 [2]中国科学院大学,北京100049

出　　处：《热带海洋学报》2014年第5期74-83,共10页Journal of Tropical Oceanography

基　　金：国家自然科学基金项目(91028002、41176053、41076029)

摘　　要：FAST(first arrival seismic tomography)软件是获取复杂地区三维深部结构的最常用工具之一,而反演参数选取是快速有效地获得真实合理的地震结构的关键环节。以南海中央次海盆三维地震探测数据为基础,采用先固定其中一个参数、选取另外一个参数、再综合选取的控制变量法,详细地介绍了FAST反演参数组合的选取过程。选取结果表明,反演参数组合(阻尼因子λ=2,平滑度权重因子sz=1,反演次数I=4)为南海中央次海盆三维地震结构的最佳反演参数,由此获得的最佳初步速度模型表明中央次海盆具有典型慢速扩张的洋壳结构。此项反演参数选取工作不仅为珍贝-黄岩海山链精细三维地震结构的正式模拟奠定了基础,同时为FAST软件在其他地区的应用提供了丰富的经验与借鉴。First arrival seismic tomography （FAST） is one of the most widely used seismic tomography tools to achieve complicated three-dimensional （3D） deep crustal structure. The selection of optimal inversion parameters for FAST is a key to obtain a reasonable velocity model effectively. Based on the 3D seismic survey data collected from the central sub-basin of the South China Sea （SCS）, the selection process of inversion parameters was illustrated in detail in this paper, using the control variate method, namely, selecting one parameter while fixing the other parameters, and then selecting the combination of all parameters comprehensively. The result showed that the combination of parameters （damping parameterλ=2, smoothness weighting parametersz=1, inversion numberI=4） was an assembly of optimal inversion parameters for the 3D seismic structure of the central sub-basin of the SCS. The preferred preliminary velocity structure acquired by this combination indicated that the central sub-basin could be classified as a typical slow-spreading oceanic crust. The research of choosing inversion parameters not only lays a foundation for further modeling of detailed 3D seismic structure of the Zhenbei-Huangyan seamount chain but also provides reference and experience for the application of FAST software in other potential areas.

关 键 词：初至波层析成像 反演参数 三维地震探测 中央次海盆 first ARRIVAL SEISMIC tomography (FAST) 

分 类 号：P631.443[天文地球—地质矿产勘探]