The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway
Magnetotelluric data, collected from 30 stations on Spitsbergen as part of a reconnaissance geothermal resource assessment along a profile with 0.5–3-km spacing in 0.003–1000-s period range, were used to develop a lithospheric-scale two-dimensional (2D) resistivity model, heretofore unavailable for...
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Norwegian Polar Institute
2015
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ftdoajarticles:oai:doaj.org/article:39c059ab37ab4d6b966d52aaae59e72a 2023-05-15T15:11:50+02:00 The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway Thomas I. Beka Maxim Smirnov Steffen G. Bergh Yngve Birkelund 2015-12-01T00:00:00Z https://doi.org/10.3402/polar.v34.26766 https://doaj.org/article/39c059ab37ab4d6b966d52aaae59e72a EN eng Norwegian Polar Institute http://www.polarresearch.net/index.php/polar/article/view/26766/pdf_60 https://doaj.org/toc/1751-8369 1751-8369 doi:10.3402/polar.v34.26766 https://doaj.org/article/39c059ab37ab4d6b966d52aaae59e72a Polar Research, Vol 34, Iss 0, Pp 1-12 (2015) Magnetotellurics 2D modelling lithosphere architecture geothermal Svalbard Environmental sciences GE1-350 Oceanography GC1-1581 article 2015 ftdoajarticles https://doi.org/10.3402/polar.v34.26766 2022-12-31T04:30:35Z Magnetotelluric data, collected from 30 stations on Spitsbergen as part of a reconnaissance geothermal resource assessment along a profile with 0.5–3-km spacing in 0.003–1000-s period range, were used to develop a lithospheric-scale two-dimensional (2D) resistivity model, heretofore unavailable for the region. Inverting the determinant of the impedance tensor in 2D, we found the smoothest model fitting the data within a specified tolerance level. We justified the model by perturbing it, performing sensitivity analysis and re-running the inversion with a different algorithm and starting models. From our final model, we constructed a crustal-scale stratigraphic framework, using it to estimate the depth of major geological features and to locate structural deformations. The 2D resistivity model indicates a shallow low resistive (<100 Ωm) Paleozoic–Mesozoic sedimentary sequence, varying laterally in thickness (2–4 km), obstructed by a gently dipping Permian–Carboniferous succession (>1000 Ωm) east of the Billefjorden Fault Zone. Underneath, a (possibly Devonian) basin is imaged as a thick conductive anomaly stretching >15 km downwards. Beneath a deformed Paleozoic–Mesozoic successions, an uplifted pre-Devonian shallow basement (>3000 Ωm) is revealed. We estimated a thin lithosphere, in the range of ca. 55–100 km thick, that could explain the area's elevated surface heat flow (ca. 60–90 mW/m2), consistent with the calculated depth of thermal lithosphere heat-base boundaries for a partially melting mantle. The model indicates a possible replenishment pathway of upward heat transport from the shallow convective mantle to the composite crustal conductive units. This is encouraging for low-enthalpy geothermal development. Article in Journal/Newspaper Arctic Billefjorden Polar Research Svalbard Spitsbergen Directory of Open Access Journals: DOAJ Articles Arctic Svalbard Norway Billefjorden ENVELOPE(16.417,16.417,78.563,78.563) Polar Research 34 1 26766 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Magnetotellurics 2D modelling lithosphere architecture geothermal Svalbard Environmental sciences GE1-350 Oceanography GC1-1581 |
spellingShingle |
Magnetotellurics 2D modelling lithosphere architecture geothermal Svalbard Environmental sciences GE1-350 Oceanography GC1-1581 Thomas I. Beka Maxim Smirnov Steffen G. Bergh Yngve Birkelund The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway |
topic_facet |
Magnetotellurics 2D modelling lithosphere architecture geothermal Svalbard Environmental sciences GE1-350 Oceanography GC1-1581 |
description |
Magnetotelluric data, collected from 30 stations on Spitsbergen as part of a reconnaissance geothermal resource assessment along a profile with 0.5–3-km spacing in 0.003–1000-s period range, were used to develop a lithospheric-scale two-dimensional (2D) resistivity model, heretofore unavailable for the region. Inverting the determinant of the impedance tensor in 2D, we found the smoothest model fitting the data within a specified tolerance level. We justified the model by perturbing it, performing sensitivity analysis and re-running the inversion with a different algorithm and starting models. From our final model, we constructed a crustal-scale stratigraphic framework, using it to estimate the depth of major geological features and to locate structural deformations. The 2D resistivity model indicates a shallow low resistive (<100 Ωm) Paleozoic–Mesozoic sedimentary sequence, varying laterally in thickness (2–4 km), obstructed by a gently dipping Permian–Carboniferous succession (>1000 Ωm) east of the Billefjorden Fault Zone. Underneath, a (possibly Devonian) basin is imaged as a thick conductive anomaly stretching >15 km downwards. Beneath a deformed Paleozoic–Mesozoic successions, an uplifted pre-Devonian shallow basement (>3000 Ωm) is revealed. We estimated a thin lithosphere, in the range of ca. 55–100 km thick, that could explain the area's elevated surface heat flow (ca. 60–90 mW/m2), consistent with the calculated depth of thermal lithosphere heat-base boundaries for a partially melting mantle. The model indicates a possible replenishment pathway of upward heat transport from the shallow convective mantle to the composite crustal conductive units. This is encouraging for low-enthalpy geothermal development. |
format |
Article in Journal/Newspaper |
author |
Thomas I. Beka Maxim Smirnov Steffen G. Bergh Yngve Birkelund |
author_facet |
Thomas I. Beka Maxim Smirnov Steffen G. Bergh Yngve Birkelund |
author_sort |
Thomas I. Beka |
title |
The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway |
title_short |
The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway |
title_full |
The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway |
title_fullStr |
The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway |
title_full_unstemmed |
The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway |
title_sort |
first magnetotelluric image of the lithospheric-scale geological architecture in central svalbard, arctic norway |
publisher |
Norwegian Polar Institute |
publishDate |
2015 |
url |
https://doi.org/10.3402/polar.v34.26766 https://doaj.org/article/39c059ab37ab4d6b966d52aaae59e72a |
long_lat |
ENVELOPE(16.417,16.417,78.563,78.563) |
geographic |
Arctic Svalbard Norway Billefjorden |
geographic_facet |
Arctic Svalbard Norway Billefjorden |
genre |
Arctic Billefjorden Polar Research Svalbard Spitsbergen |
genre_facet |
Arctic Billefjorden Polar Research Svalbard Spitsbergen |
op_source |
Polar Research, Vol 34, Iss 0, Pp 1-12 (2015) |
op_relation |
http://www.polarresearch.net/index.php/polar/article/view/26766/pdf_60 https://doaj.org/toc/1751-8369 1751-8369 doi:10.3402/polar.v34.26766 https://doaj.org/article/39c059ab37ab4d6b966d52aaae59e72a |
op_doi |
https://doi.org/10.3402/polar.v34.26766 |
container_title |
Polar Research |
container_volume |
34 |
container_issue |
1 |
container_start_page |
26766 |
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1766342617615826944 |