uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The electrical conductivity distribution of the Hallandsas Horst, Sweden: a controlled source radiomagnetotelluric study
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
2011 (English)In: Near Surface Geophysics, ISSN 1569-4445, Vol. 9, no 1, p. 45-54Article in journal (Refereed) Published
Abstract [en]

We studied the behaviour of controlled source responses of 2 1/2D synthetic models based on controlled source tensor magnetotelluric (f=1-12 kHz) and radio magnetotelluric (f=14-250 kHz) data sets collected along profiles on the Hallandsas Horst, Southern Sweden, with a view to study the depth extent of possible near-surface fractures zones that might intersect a tunnel under construction. Based upon 2.5D forward modelling of the transverse electric (TE) and transverse magnetic (TM) mode radio magnetotelluric data, a simplified 2D model was constructed such that a dipping conductor was continued down to a depth of 140 m, which is the depth of the tunnel. Based on this extended model, we calculated both plane wave and controlled source responses for the frequency range 1-250 kHz corresponding to the source location in the study. Finally, we inverted both data sets under plane wave assumptions. When comparing synthetic controlled source and plane wave data in the frequency range 1-12 kHz, we find that the controlled source tensor magnetotelluric transfer functions generally deviate from the plane wave condition for frequencies less than 6 kHz. The phases are much more distorted than apparent resistivities. The TM mode phases, in particular, are generally distorted for frequencies less than 6 kHz. Regarding the vertical magnetic fields, we find that at all frequencies the real part of tippers are distorted by source effects but the tipper component along the profile direction is much less affected by the off-profile lying controlled source tensor magnetotelluric source than the tipper component orthogonal to the profile direction. Based upon synthetic model studies of combined controlled source tensor magnetotelluric and radio magnetotelluric responses, we find that determinant data are less distorted than individual TE- and TM-mode data. On the other hand, TE- and TM-responses have greater resolving power and, when used with care (selecting data that are weakly distorted by source effects), the corresponding models can resolve the conductor down to tunnel depths.

Place, publisher, year, edition, pages
2011. Vol. 9, no 1, p. 45-54
National Category
Earth and Related Environmental Sciences
Identifiers
URN: urn:nbn:se:uu:diva-148589DOI: 10.3997/1873-0604.2010049ISI: 000287461300004OAI: oai:DiVA.org:uu-148589DiVA, id: diva2:402559
Available from: 2011-03-08 Created: 2011-03-08 Last updated: 2011-03-08Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text
By organisation
Geophysics
Earth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 396 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf