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An Efficient 3D Inversion of MT Data Using Approximate Sensitivities  

Han, Nu-Ree (Dept. of Civil, Urban and Geosystem Eng., Seoul National University)
Nam, Myung-Jin (Dept. of Petroleum and Geosystems Eng., The University of Texas at Austin)
Kim, Hee-Joon (Dept. of Environmental Exploration Eng., Pukyong National University)
Lee, Tae-Jong (Groundwater and Geothermal Resources Div., KIGAM)
Song, Yoon-Ho (Groundwater and Geothermal Resources Div., KIGAM)
Suh, Jung-Hee (Dept. of Civil, Urban and Geosystem Eng., Seoul National University)
Publication Information
Geophysics and Geophysical Exploration / v.10, no.4, 2007 , pp. 259-267 More about this Journal
Abstract
An efficient algorithm for inverting static-shifted magnetotelluric (MT) data has been proposed to produce a three-dimensional (3D) resistivity model. In the Gauss-Newton approach, computational costs associated with construction of a full sensitivity matrix usually make 3D MT inversion impractical. This computational difficulty may be overcome by using approximate sensitivities. We use four kinds of sensitivities in particular orders in the inversion process. These sensitivities are computed 1) analytically for an initial, homogeneous earth, 2) exactly for a current model, 3) approximately by the Broyden method, and 4) approximately using the previous adjoint fields. Inversion experiments with static-shifted synthetic and field MT data indicate that inversion results are highly dependent on characteristics of data and thus applying various combinations of sensitivities is helpful in obtaining a good image of the subsurface structure with reasonable computation time.
Keywords
3D; MT; inversion; approximate sensitivity;
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Times Cited By KSCI : 4  (Citation Analysis)
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1 Guptasarma, D., and Singh, B., 1997, New digital linear filters for Hankel $J_0\;and\;J_1$ transforms, Geophys. Prosp., 45, 745- 762   DOI   ScienceOn
2 Lee, T. J., Song, Y., and Uchida, T., 2007, Three-dimensional magnetotelluric surveys for geothermal development in Pohang, Korea, Butsuri-Tansa, 60   과학기술학회마을
3 Lee, T. J., Song, Y., and Uchida, T., 2007, Three-dimensional magnetotelluric surveys for geothermal development in Pohang, Korea, Mulli-Tamsa, 10, 44-49   과학기술학회마을
4 Mackie, R. L., and Madden, T. R., 1993, Three-dimensional magnetotelluric inversion using conjugate gradients, Geophys. J. Int., 115, 215-229   DOI   ScienceOn
5 McGillivray, P. R., Oldenburg, D. W., Ellis, R. G., and Habashy, T. M., 1994, Calculation of sensitivities for the frequencydomain electromagnetic problem, Geophys. J. Int., 116, 1-4   DOI
6 Newman, G. A., and Alumbaugh, D. L., 2000, Three-dimensional magnetotelluric inversion using non-linear conjugate gradients, Goephys., J. Int., 140, 410-424   DOI   ScienceOn
7 Ogawa, Y., and Uchida, T., 1996, A two-dimensional magnetotelluric inversion assuming Gaussian static shift, Geophys. J. Int., 126, 69-76   DOI   ScienceOn
8 Sasaki, Y., 2001, Full 3-D inversion of electromagnetic data on PC, Journal of Applied Geophysics, 46, 45-54   DOI   ScienceOn
9 Sasaki, Y., 2004, Three-dimensional inversion of static-shifted magnetotelluric data, Earth Planets Space, 56, 239-248   DOI
10 Siripunvaraporn, W., Egbert, G., Lenbury, Y., and Uyeshina, M., 2005, Three-dimensional magnetotelluric inversion: dataspace method, Physics of the Earth and Planetary Interiors, 150, 3-14   DOI   ScienceOn
11 Yee, K. S., 1966, Numerical solution of initial boundary value problems involving Maxwell's equation in isotropic media, IEEE Trans. Anten. Prop., AP-14, 302-307
12 Jones, A. G., 1988, Static shift of magnetotelluric data and its removal in a sedimentary basin environment, Geophysics, 53, 967-978   DOI
13 Zhdanov, M. S., Fang, S., and Hursan, G., 2000, Electromagnetic inversion using quasi-linear approximation, Geophysics, 65, 1501-1513   DOI
14 Lock, M. H., and Barker, R. D., 1996, Practical technique for 3D resistivity surveys and data inversion, Geophys. Prosp., 44, 499-523   DOI   ScienceOn
15 Sasaki, Y., and Meju, M. A., 2006, Three-dimensional joint inversion for magnetotelluric resistivity and static shift distributions in complex media, J. Geophys. Res., 111, B05101
16 deGroot-Hedlin, C., 1991, Removal of static shift in two dimensions by regularized inversion, Geophysics, 56, 2102-2106   DOI
17 Constable, S., and Weiss, C., 2006, Mapping thin resistors and hydrocarbons with marine EM methods: Insights from 1D modeling, Geophysics, 71, G43-G51
18 Unsworth, M. J., Travis, B. J., and Chave, A. D., 1993, Electromagnetic induction by a finite electric dipole source over a 2- D earth, Geophysics, 58, 198-214   DOI
19 Smith, J. T., 1996, Conservative modeling of 3-D electromagnetic fields, Part I: properties and error analysis, Geophysics, 61, 1308-1318   DOI   ScienceOn
20 Farquharson, C. G., and Oldenburg, D. W., 1999, Approximate sensitivities for multidimensional electromagnetic inversion, in Three-dimensional Electromagnetics, Oristaglio M. L., and Spies, B. R. (eds), SEG, 256-264
21 Torres-Verdin, C., and Bostick, F. X. J., 1992, Principles of spatial surface electric field filtering in magnetotellurics: Electromagnetic array profiling (EMAP), Geophysics, 57, 603-622   DOI
22 Lee, T. J., Song, Y., and Uchida, T., 2007, Three-dimensional magnetotelluric surveys for geothermal development in Pohang, Korea, Exploration Geophysics, 38
23 김희준, 남명진, 한누리, 최지향, 이태종, 송윤호, 서정희, 2004, MT 자료의 3차원 역산 개관, 물리탐사, 7, 207-212
24 이태종, 송윤호, Uchida, T., 2005, 포항 지열개발 지역 MT 탐사 자료의 2차원 및 3차원 해석, 한국지구시스템공학회지, 297-307
25 Siripunvaraporn, W., Egbert, G., and Lenbury, Y., 2002, Numerical accuracy of magnetotelluric modeling: A comparison of finite difference approximations, Earth Planets Space, 54, 721-725   DOI