Three-dimensional inversion of magnetotelluric resistivity model with galvanic distortion
文献类型：期刊论文
| 作者 | Li Xin1,2; Bai Deng-Hai1; Yan Yong-Li1; Ma Xiao-Bing1; Kong Xiang-Ru1 |
| 刊名 | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
 |
| 出版日期 | 2016-06-01 |
| 卷号 | 59期号:6页码:2302-2315 |
| 关键词 | Galvanic Distortion Static Shift 3-d Inversion Magnetotelluric |
| DOI | 10.6038/cjg20160632 |
| 文献子类 | Article |
| 英文摘要 | Galvanic distortion, which is caused by shallow small-scale inhomogeneities or topography, has long been recognized as an obstacle in magnetotelluric (MT) sounding studies. Removal of these distortions from the field-observed MT data is essential to obtain a reliable model of the subsurface electrical structure. In two-dimensional (2-D) situations, a number of impedance decomposition methods have been widely used for distortion removal. For data from three-dimensional (3-D) structures, however, the effects of galvanic distortion become far more complex and cannot be solved by these traditional methods. This paper proposes a method that employs the Nonlinear Conjugate Gradient algorithm (NLCG) to solve both the regional resistivity structures and the parameters of full galvanic distortion during iterations. The statistical distribution of galvanic distortion is firstly estimated by using the phase tensor method and suggests that the off-diagonal elements of the distortion tensor are quasi-symmetrically distributed around zero, and the diagonal elements are centralized around one. Using the prior information contained in the field data, we build a new objective function that takes the galvanic effects into consideration and adds an extra constraint on the distortion parameters. Furthermore, to ensure stability and efficiency of the algorithm, an adaptive regularized strategy is used to determine the trade-off factors between the data misfit term and the roughness terms of the resistivity model and galvanic distortion respectively. The synthetic model study suggests that conventional inversion approach cannot reasonably explain the distorted part of the synthetic data and will inevitably bring erroneous structures to the resistivity model. In contrast, our new inversion algorithm can reliably retrieve both the regional resistivity structures and galvanic distortion, irrespective of whether galvanic distortion is present or not. |
| WOS关键词 | NONLINEAR CONJUGATE GRADIENTS ; ALTYN TAGH FAULT ; IMPEDANCE TENSOR ; NEAR-SURFACE ; STATIC SHIFT ; PHASE TENSOR ; DECOMPOSITION ; SCATTERERS ; INDUCTION ; ALGORITHM |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000377628800032 |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/53429]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Li Xin,Bai Deng-Hai,Yan Yong-Li,et al. Three-dimensional inversion of magnetotelluric resistivity model with galvanic distortion[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2016,59(6):2302-2315. |
| APA | Li Xin,Bai Deng-Hai,Yan Yong-Li,Ma Xiao-Bing,&Kong Xiang-Ru.(2016).Three-dimensional inversion of magnetotelluric resistivity model with galvanic distortion.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,59(6),2302-2315. |
| MLA | Li Xin,et al."Three-dimensional inversion of magnetotelluric resistivity model with galvanic distortion".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 59.6(2016):2302-2315. |
入库方式： OAI收割
来源：地质与地球物理研究所
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