Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines

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In previous works, we presented 2-D and 3-D magnetotelluric modelling methods based on Rayleigh-Fourier expansions. These methods are an alternative to finite-element and finite-difference techniques and are especially suitable for modelling multilayered structures, with smooth irregular boundaries....

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Autores principales: Martinelli, P., Osella, A.
Formato: Artículo publishedVersion
Publicado: 2003
Materias:
Daily variations
Geo-electromagnetic induction
Non-uniform inducing fields
Source effects
coastal morphology
electromagnetic method
induced polarization
magnetotelluric method
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0956540X_v155_n2_p623_Martinelli
https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_0956540X_v155_n2_p623_Martinelli_oai
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id I28-R145-paper_0956540X_v155_n2_p623_Martinelli_oai
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spelling I28-R145-paper_0956540X_v155_n2_p623_Martinelli_oai2024-08-16 Martinelli, P. Osella, A. 2003 In previous works, we presented 2-D and 3-D magnetotelluric modelling methods based on Rayleigh-Fourier expansions. These methods are an alternative to finite-element and finite-difference techniques and are especially suitable for modelling multilayered structures, with smooth irregular boundaries. Here we generalize the 2-D method for the calculation of the electromagnetic response of 2-D structures to arbitrary, spatially non-uniform 2-D and 3-D inducing magnetic fields. These fields are characteristic of low- and high-latitude regions. We calculate the response to different 2-D and 3-D sources, of a 2-D structure representative of the conductivity distribution which could be found at a coastline, which includes deep conductive anomalies in the lower crust and upper mantle. Then, we investigate source effects, comparing these responses to that obtained for a uniform source. These effects become noticeable for periods greater than approximately 6 h and increase with the period of the source. They are highly dependent on the morphology of the source and also on the orientation of the external field relative to the strike direction of the structure. In various cases, they totally mask the uniform source response. Fil:Osella, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. application/pdf http://hdl.handle.net/20.500.12110/paper_0956540X_v155_n2_p623_Martinelli info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar Geophys. J. Int. 2003;155(2):623-640 Daily variations Geo-electromagnetic induction Non-uniform inducing fields Source effects coastal morphology electromagnetic method induced polarization magnetotelluric method Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_0956540X_v155_n2_p623_Martinelli_oai
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-145
collection Repositorio Digital de la Universidad de Buenos Aires (UBA)
topic Daily variations
Geo-electromagnetic induction
Non-uniform inducing fields
Source effects
coastal morphology
electromagnetic method
induced polarization
magnetotelluric method
spellingShingle Daily variations
Geo-electromagnetic induction
Non-uniform inducing fields
Source effects
coastal morphology
electromagnetic method
induced polarization
magnetotelluric method
Martinelli, P.
Osella, A.
Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines
topic_facet Daily variations
Geo-electromagnetic induction
Non-uniform inducing fields
Source effects
coastal morphology
electromagnetic method
induced polarization
magnetotelluric method
description In previous works, we presented 2-D and 3-D magnetotelluric modelling methods based on Rayleigh-Fourier expansions. These methods are an alternative to finite-element and finite-difference techniques and are especially suitable for modelling multilayered structures, with smooth irregular boundaries. Here we generalize the 2-D method for the calculation of the electromagnetic response of 2-D structures to arbitrary, spatially non-uniform 2-D and 3-D inducing magnetic fields. These fields are characteristic of low- and high-latitude regions. We calculate the response to different 2-D and 3-D sources, of a 2-D structure representative of the conductivity distribution which could be found at a coastline, which includes deep conductive anomalies in the lower crust and upper mantle. Then, we investigate source effects, comparing these responses to that obtained for a uniform source. These effects become noticeable for periods greater than approximately 6 h and increase with the period of the source. They are highly dependent on the morphology of the source and also on the orientation of the external field relative to the strike direction of the structure. In various cases, they totally mask the uniform source response.
format Artículo
Artículo
publishedVersion
author Martinelli, P.
Osella, A.
author_facet Martinelli, P.
Osella, A.
author_sort Martinelli, P.
title Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines
title_short Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines
title_full Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines
title_fullStr Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines
title_full_unstemmed Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines
title_sort modelling electromagnetic responses of 2-d structures due to spatially non-uniform inducing fields. analysis of magnetotelluric source effects at coastlines
publishDate 2003
url http://hdl.handle.net/20.500.12110/paper_0956540X_v155_n2_p623_Martinelli
https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_0956540X_v155_n2_p623_Martinelli_oai
work_keys_str_mv AT martinellip modellingelectromagneticresponsesof2dstructuresduetospatiallynonuniforminducingfieldsanalysisofmagnetotelluricsourceeffectsatcoastlines
AT osellaa modellingelectromagneticresponsesof2dstructuresduetospatiallynonuniforminducingfieldsanalysisofmagnetotelluricsourceeffectsatcoastlines
_version_ 1809356915683098624

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