Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica
Permafrost is ubiquitous at high latitudes, and its thickness is controlled by important local factors like geothermal flux, ground surface temperature and thermal properties of the subsurface. We use airborne transient electromagnetic resistivity measurements to determine permafrost thickness on th...
Published in: | Exploration Geophysics |
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2020
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Online Access: | https://pure.au.dk/portal/da/publications/mapping-geothermal-heat-flux-using-permafrost-thickness-constrained-by-airborne-electromagnetic-surveys-on-the-western-coast-of-ross-island-antarctica(bf04d7c9-c9dd-4e63-96df-94581fec3613).html https://doi.org/10.1080/08123985.2019.1651618 http://www.scopus.com/inward/record.url?scp=85070954433&partnerID=8YFLogxK |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/bf04d7c9-c9dd-4e63-96df-94581fec3613 2023-10-29T02:32:06+01:00 Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica Foley, Neil Tulaczyk, Slawomir Auken, Esben Grombacher, Denys Mikucki, Jill Foged, Nikolaj Myers, Krista Dugan, Hilary Doran, Peter T. Virginia, Ross A. 2020-01 https://pure.au.dk/portal/da/publications/mapping-geothermal-heat-flux-using-permafrost-thickness-constrained-by-airborne-electromagnetic-surveys-on-the-western-coast-of-ross-island-antarctica(bf04d7c9-c9dd-4e63-96df-94581fec3613).html https://doi.org/10.1080/08123985.2019.1651618 http://www.scopus.com/inward/record.url?scp=85070954433&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Foley , N , Tulaczyk , S , Auken , E , Grombacher , D , Mikucki , J , Foged , N , Myers , K , Dugan , H , Doran , P T & Virginia , R A 2020 , ' Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica ' , Exploration Geophysics , vol. 51 , no. 1 , pp. 84-93 . https://doi.org/10.1080/08123985.2019.1651618 Antarctica electrical resistivity Geothermal flux permafrost MOUNT EREBUS TIME-DOMAIN MCMURDO VOLCANO SEA-ICE THICKNESS THERMAL-CONDUCTIVITY INVERSION FLOW ERUPTIVE HISTORY CLIMATE article 2020 ftuniaarhuspubl https://doi.org/10.1080/08123985.2019.1651618 2023-10-04T22:58:49Z Permafrost is ubiquitous at high latitudes, and its thickness is controlled by important local factors like geothermal flux, ground surface temperature and thermal properties of the subsurface. We use airborne transient electromagnetic resistivity measurements to determine permafrost thickness on the coast of Ross Island, Antarctica, which contains the active volcano Mt Erebus. Here, resistivity data clearly distinguish resistive permafrost from the electrically conductive fluid-saturated materials underlying it. For our study, we define permafrost as frozen material with a resistivity > 100 Ω·m; more conductive material contains a significant fraction of water or (more likely) brine. We observe that permafrost is very thin near the coast and thickens within several hundred metres inland to reach depths that are typically within the range of 300–400 m. We attribute the sharp near-shore increase in permafrost thickness to lateral heat conduction from the relatively warm ocean, possibly combined with seawater infiltration into the near-shore permafrost. We validate this result with a two-dimensional heat flow model and conclude that away from the thermal influence of the ocean, the local geothermal gradient and heat flux are about 45 ± 5 °C/km and 90 ± 13 mW/m 2 , respectively. These values are in line with published estimates in the vicinity of Mt Erebus and within the actively extending Terror Rift, but do not reflect a strong heat flow anomaly from volcanic activity of Mt Erebus. Measurements made previously in the McMurdo Dry Valleys, on the other side of McMurdo Sound, tend to be a few dozens of mW/m 2 lower, likely reflecting its different tectonic setting on the uplifted rift shoulder of Transantarctic Mountains. Our study demonstrates a new approach towards constraining geothermal flux in polar regions using airborne electromagnetic (AEM) data that can be relatively efficiently collected on regional scales where ice coverage does not exceed the penetration limits of the AEM device, which for the device ... Article in Journal/Newspaper Antarc* Antarctica Ice McMurdo Dry Valleys McMurdo Sound permafrost Ross Island Sea ice Aarhus University: Research Exploration Geophysics 51 1 84 93 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Antarctica electrical resistivity Geothermal flux permafrost MOUNT EREBUS TIME-DOMAIN MCMURDO VOLCANO SEA-ICE THICKNESS THERMAL-CONDUCTIVITY INVERSION FLOW ERUPTIVE HISTORY CLIMATE |
spellingShingle |
Antarctica electrical resistivity Geothermal flux permafrost MOUNT EREBUS TIME-DOMAIN MCMURDO VOLCANO SEA-ICE THICKNESS THERMAL-CONDUCTIVITY INVERSION FLOW ERUPTIVE HISTORY CLIMATE Foley, Neil Tulaczyk, Slawomir Auken, Esben Grombacher, Denys Mikucki, Jill Foged, Nikolaj Myers, Krista Dugan, Hilary Doran, Peter T. Virginia, Ross A. Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica |
topic_facet |
Antarctica electrical resistivity Geothermal flux permafrost MOUNT EREBUS TIME-DOMAIN MCMURDO VOLCANO SEA-ICE THICKNESS THERMAL-CONDUCTIVITY INVERSION FLOW ERUPTIVE HISTORY CLIMATE |
description |
Permafrost is ubiquitous at high latitudes, and its thickness is controlled by important local factors like geothermal flux, ground surface temperature and thermal properties of the subsurface. We use airborne transient electromagnetic resistivity measurements to determine permafrost thickness on the coast of Ross Island, Antarctica, which contains the active volcano Mt Erebus. Here, resistivity data clearly distinguish resistive permafrost from the electrically conductive fluid-saturated materials underlying it. For our study, we define permafrost as frozen material with a resistivity > 100 Ω·m; more conductive material contains a significant fraction of water or (more likely) brine. We observe that permafrost is very thin near the coast and thickens within several hundred metres inland to reach depths that are typically within the range of 300–400 m. We attribute the sharp near-shore increase in permafrost thickness to lateral heat conduction from the relatively warm ocean, possibly combined with seawater infiltration into the near-shore permafrost. We validate this result with a two-dimensional heat flow model and conclude that away from the thermal influence of the ocean, the local geothermal gradient and heat flux are about 45 ± 5 °C/km and 90 ± 13 mW/m 2 , respectively. These values are in line with published estimates in the vicinity of Mt Erebus and within the actively extending Terror Rift, but do not reflect a strong heat flow anomaly from volcanic activity of Mt Erebus. Measurements made previously in the McMurdo Dry Valleys, on the other side of McMurdo Sound, tend to be a few dozens of mW/m 2 lower, likely reflecting its different tectonic setting on the uplifted rift shoulder of Transantarctic Mountains. Our study demonstrates a new approach towards constraining geothermal flux in polar regions using airborne electromagnetic (AEM) data that can be relatively efficiently collected on regional scales where ice coverage does not exceed the penetration limits of the AEM device, which for the device ... |
format |
Article in Journal/Newspaper |
author |
Foley, Neil Tulaczyk, Slawomir Auken, Esben Grombacher, Denys Mikucki, Jill Foged, Nikolaj Myers, Krista Dugan, Hilary Doran, Peter T. Virginia, Ross A. |
author_facet |
Foley, Neil Tulaczyk, Slawomir Auken, Esben Grombacher, Denys Mikucki, Jill Foged, Nikolaj Myers, Krista Dugan, Hilary Doran, Peter T. Virginia, Ross A. |
author_sort |
Foley, Neil |
title |
Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica |
title_short |
Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica |
title_full |
Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica |
title_fullStr |
Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica |
title_full_unstemmed |
Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica |
title_sort |
mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of ross island, antarctica |
publishDate |
2020 |
url |
https://pure.au.dk/portal/da/publications/mapping-geothermal-heat-flux-using-permafrost-thickness-constrained-by-airborne-electromagnetic-surveys-on-the-western-coast-of-ross-island-antarctica(bf04d7c9-c9dd-4e63-96df-94581fec3613).html https://doi.org/10.1080/08123985.2019.1651618 http://www.scopus.com/inward/record.url?scp=85070954433&partnerID=8YFLogxK |
genre |
Antarc* Antarctica Ice McMurdo Dry Valleys McMurdo Sound permafrost Ross Island Sea ice |
genre_facet |
Antarc* Antarctica Ice McMurdo Dry Valleys McMurdo Sound permafrost Ross Island Sea ice |
op_source |
Foley , N , Tulaczyk , S , Auken , E , Grombacher , D , Mikucki , J , Foged , N , Myers , K , Dugan , H , Doran , P T & Virginia , R A 2020 , ' Mapping geothermal heat flux using permafrost thickness constrained by airborne electromagnetic surveys on the western coast of Ross Island, Antarctica ' , Exploration Geophysics , vol. 51 , no. 1 , pp. 84-93 . https://doi.org/10.1080/08123985.2019.1651618 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1080/08123985.2019.1651618 |
container_title |
Exploration Geophysics |
container_volume |
51 |
container_issue |
1 |
container_start_page |
84 |
op_container_end_page |
93 |
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1781053179213905920 |