Geoelectrical modeling of shallow structures using parallel and perpendicular arrays

In this article we analyze the sensitivity of a geoelectrical modeling technique to image 2D shallow structures. Firstly, we extend a previously developed 2D method based on Rayleigh-Fourier expansions, in order to allow arbitrary locations for the electrodes and also 3D earth models. This method is...

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Autores principales: Bonomo, Néstor Eduardo, Osella, Ana María
Publicado: 2002
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13438832_v54_n5_p523_Bonomo
http://hdl.handle.net/20.500.12110/paper_13438832_v54_n5_p523_Bonomo
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spelling paper:paper_13438832_v54_n5_p523_Bonomo2023-06-08T16:10:41Z Geoelectrical modeling of shallow structures using parallel and perpendicular arrays Bonomo, Néstor Eduardo Osella, Ana María buried structure electromagnetic survey In this article we analyze the sensitivity of a geoelectrical modeling technique to image 2D shallow structures. Firstly, we extend a previously developed 2D method based on Rayleigh-Fourier expansions, in order to allow arbitrary locations for the electrodes and also 3D earth models. This method is an alternative to finite element and finite difference techniques and is especially suitable to model multilayered structures, with smooth irregular boundaries. Then, for simple 2D models we build up two synthetic pseudosections, one for electrode deployments parallel to a profile perpendicular to the strike, and other for deployments perpendicular to it. We analyze the advantages in using both pseudosections to model these structures. We also compare geoelectric results with the corresponding audiomagnetotelluric transverse electric and transverse magnetic responses. Finally, we perform a geoelectrical survey to image a shallow buried structure and show the goodness of the model fit obtained considering both pseudosections. For the examples studied here, we conclude that considering both pseudosections leads to a more accurate description of the structures. When a 2D anomaly is present, its effect on the perpendicular component is more focused, both in width and depth, than in the parallel component. Hence the perpendicular component helps to constrain the localization of the inhomogeneity. In addition, we find similarities between the geoelectric parallel and perpendicular responses and the corresponding audiomagnetotelluric transverse magnetic and transverse electric results, respectively. When inverting audiomagnetotelluric data using 2D codes, better resolution in the electrical imaging is obtained when both modes are considered; then it is expected that 2D imaging of geoelectric data including both arrays should lead to an optimization of the inversion process. Even more, if results of these inversions could be used in correlation with AMT results, it is clear that this kind of joint inversion should contribute to remove uncertainties allowing an improvement in the description of the actual structures. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. Fil:Bonomo, N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Osella, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2002 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13438832_v54_n5_p523_Bonomo http://hdl.handle.net/20.500.12110/paper_13438832_v54_n5_p523_Bonomo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic buried structure
electromagnetic survey
spellingShingle buried structure
electromagnetic survey
Bonomo, Néstor Eduardo
Osella, Ana María
Geoelectrical modeling of shallow structures using parallel and perpendicular arrays
topic_facet buried structure
electromagnetic survey
description In this article we analyze the sensitivity of a geoelectrical modeling technique to image 2D shallow structures. Firstly, we extend a previously developed 2D method based on Rayleigh-Fourier expansions, in order to allow arbitrary locations for the electrodes and also 3D earth models. This method is an alternative to finite element and finite difference techniques and is especially suitable to model multilayered structures, with smooth irregular boundaries. Then, for simple 2D models we build up two synthetic pseudosections, one for electrode deployments parallel to a profile perpendicular to the strike, and other for deployments perpendicular to it. We analyze the advantages in using both pseudosections to model these structures. We also compare geoelectric results with the corresponding audiomagnetotelluric transverse electric and transverse magnetic responses. Finally, we perform a geoelectrical survey to image a shallow buried structure and show the goodness of the model fit obtained considering both pseudosections. For the examples studied here, we conclude that considering both pseudosections leads to a more accurate description of the structures. When a 2D anomaly is present, its effect on the perpendicular component is more focused, both in width and depth, than in the parallel component. Hence the perpendicular component helps to constrain the localization of the inhomogeneity. In addition, we find similarities between the geoelectric parallel and perpendicular responses and the corresponding audiomagnetotelluric transverse magnetic and transverse electric results, respectively. When inverting audiomagnetotelluric data using 2D codes, better resolution in the electrical imaging is obtained when both modes are considered; then it is expected that 2D imaging of geoelectric data including both arrays should lead to an optimization of the inversion process. Even more, if results of these inversions could be used in correlation with AMT results, it is clear that this kind of joint inversion should contribute to remove uncertainties allowing an improvement in the description of the actual structures. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences.
author Bonomo, Néstor Eduardo
Osella, Ana María
author_facet Bonomo, Néstor Eduardo
Osella, Ana María
author_sort Bonomo, Néstor Eduardo
title Geoelectrical modeling of shallow structures using parallel and perpendicular arrays
title_short Geoelectrical modeling of shallow structures using parallel and perpendicular arrays
title_full Geoelectrical modeling of shallow structures using parallel and perpendicular arrays
title_fullStr Geoelectrical modeling of shallow structures using parallel and perpendicular arrays
title_full_unstemmed Geoelectrical modeling of shallow structures using parallel and perpendicular arrays
title_sort geoelectrical modeling of shallow structures using parallel and perpendicular arrays
publishDate 2002
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13438832_v54_n5_p523_Bonomo
http://hdl.handle.net/20.500.12110/paper_13438832_v54_n5_p523_Bonomo
work_keys_str_mv AT bonomonestoreduardo geoelectricalmodelingofshallowstructuresusingparallelandperpendiculararrays
AT osellaanamaria geoelectricalmodelingofshallowstructuresusingparallelandperpendiculararrays
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