It is difficult to detect the complicated 3D structures by only using a single grounded source, as it could only generate single direction current vector and will have distortion sometimes. Therefore, the authors use the electric dipole sources transient electromagnetic tensor method, which is suitable for detecting 3D structure. In combination with numerical models, the authors present the data with the tensor apparent resistivity It is found that in uniform half-space and layered earth, the coordinate invariant P2 has a good representation for the change of underground media. In 3D model, the coordinate invariant P2 and ellipse are formed by the coordinate invariant ρmin and ρmax, which are calculated for 3D resistivity models. The authors hold that profiles of LOTEM measurements across a 3D cube structure can be used to accurately reflect the changes of the 3D structure and sketch the anomaly boundary. All of these results provide theoretical guidance for further TEM data interpretation.
朱伟国, 席振铢, 韩雪. 复合电偶源瞬变电磁张量测量[J]. 物探与化探, 2016, 40(3): 534-540.
ZHU Wei-Guo, XI Zhen-Zhu, HAN Xue. A study of electric dipole transient electromagnetic tensor survey. Geophysical and Geochemical Exploration, 2016, 40(3): 534-540.
[1] 牛之琏. 时间域电磁法原理[M]. 长沙: 中南大学出版社, 2007: 8-10.
[2] 朴化荣.电磁测深法原理[M]. 北京: 地质出版社, 1990: 10-27.
[3] Strack K M. Exploration with deep transient electromagnetics[M]. Amsterdam:Elsevier, 1992.
[4] Spies B R, Eggers D E. The use and misuse of a pparent resistivity in electromagnetic methods[J]. Geophysics, 1986, 51(7): 1462-1471.
[5] 严良俊, 胡文宝, 陈清礼. 长偏移距瞬变电磁测深的全区视电阻率求取及快速反演方法[J]. 石油地球物理勘探, 1999, 34(5): 532-538.
[6] 白登海, Maxwell A Meju, 卢健,等. 时间域瞬变电磁法中心方式全程视电阻率的数值计算[J]. 地球物理学报, 2003, 46(5): 697-704.
[7] Bibby H M. The apparent resistivity tensor [J]. Geophysics, 1977, 42(6): 1258-1261.
[8] Bibby H M. Analysis of multiple source bipole dipole resistivity surveys using the apparent resistivity tensor[J]. Geophysics,1986, 51(4): 972-983.
[9] Bibby H M, Hohmann G W. Three dimensional interprettation of multiple-source bipole-dipole data using the apparent resistivity tensor[J]. Geophysical Prospecting, 1993, 41: 697-723.
[10] Li X, Pederson L B. Controlled source tensor magnetitellurics[J]. Geophysics, 1991, 56(9): 1456-1461.
[11] Caldwell T G, Bibby H M. The instantneous apparent resistivity tensor: a visualization scheme for LOTEM electric field measurements[J]. Geophysical Journal International, 1998, 135: 817-834.
[12] Caldwell T G, Bibby H M, Brown C. Controlled source apparent resistivity tensors and their relationship to the magnetotelluric impedance tensor[J]. Geophysical Journal International, 2003, 151: 755-770.
[13] 陈明生.电偶源瞬变电磁测深研究(一)——基本原理[J]. 煤田地质与勘探, 1999, 27(2): 55-59.
[14] 陈明生.电偶源瞬变电磁测深研究(五)——实测感应电压转换成垂直磁场[J].煤田地质与勘探, 1999, 27(5): 54-57.
[15] Szarka L, Menvielle M. Analysis of rotational invariants of the magneto telluric impedance tensor[J]. Geophysical Journal International, 1997,129:133-142.
[16] 米萨克 N 纳比吉安. 勘察地球物理电磁法(第一卷)[M].赵经祥, 王艳君,译.北京: 地质出版社,1992:7-40.
[17] Xiong Z H. Electromagnetic fields of electrical dipoles embedded in a stratified anisotropic earth[J]. Geophysics, 1989, 54: 1643-1646.
[18] Xiong Z H. Electromagnetic modeling three-dimensional structures by the methods of system iterations using equation[J]. Geophysics, 1992, 57(12): 1556-1561.
[19] Xiong Z H, Tripp A. A block iterative algorithm for 3-D electromagnetic modeling using integral equations with symmetrized substructures[J]. Geophysics,1995,60:291-295.
[20] Zhsanov M S, Fang S. Quiasi linear approximation in 3D electromagnetic modeling[J]. Geophysics.1996,61(3): 646-665.
[21] Hursan G, Zhsanov M S. Contraction integral equation method in three-dimensional electromagnetic modeling[J].Radio Science,2002, 37(6):1089-1101.
[22] 张辉, 李桐林, 董瑞霞, 等.利用高斯求积和连分式展开计算电磁张量格林函数积分[J].地球物理学进展,2004,20(3): 667-670.