Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica)
This study aims at understanding the spatial distribution and characteristics of the frozen and unfrozen terrain in an alluvial fan on Deception Island, which is an active strato-volcano located in the Bransfield Strait (South Shetland Islands)with recent eruptions in 1967, 1969 and 1970. The alluvi...
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Online Access: | http://hdl.handle.net/10451/27205 https://doi.org/10.1016/j.geomorph.2014.04.010 |
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ftunivlisboa:oai:repositorio.ul.pt:10451/27205 2023-05-15T13:37:42+02:00 Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) Goyanes, G. Vieira, Goncalo Caselli, A. Cardoso, M. Marmy, A. Santos, F. Bernardo, I. Hauck, C. 2017-03-17T10:58:07Z http://hdl.handle.net/10451/27205 https://doi.org/10.1016/j.geomorph.2014.04.010 eng eng Elsevier Geomorphology 225 (2014) 57–68 0169-555X http://hdl.handle.net/10451/27205 doi:10.1016/j.geomorph.2014.04.010 closedAccess Permafrost Geothermal Anomaly Active Volcano Deception Island South Shetlands Antarctica article 2017 ftunivlisboa https://doi.org/10.1016/j.geomorph.2014.04.010 2022-05-25T18:36:36Z This study aims at understanding the spatial distribution and characteristics of the frozen and unfrozen terrain in an alluvial fan on Deception Island, which is an active strato-volcano located in the Bransfield Strait (South Shetland Islands)with recent eruptions in 1967, 1969 and 1970. The alluvial fan is dominated by debris-flow, run-off and rock fall processes and permafrost occurs in several parts in the vicinity of anomalous geothermal heat flux. The aim is to assess the ways volcanic activity controls permafrost development and associated geomorphic dynamics using shallow subsurface, surface and air temperature measurements as well as thaw depth and electrical resistivity tomography (ERT) surveys. Results showa temperature increasewith depth in the lower part of the fan reaching 13 °C at 0.80mdepth,without the presence of permafrost. The shallowborehole located at this site showed a stable thermal stratification all year-round, with only the upper 0.20 m reacting to meteorological forcing. In the upper part of the alluvial fan and debris cones, c. 100mfromthe coast, frozen ground is present at c. 0.70mdepth. There, the shallowborehole shows a good coupling with air temperatures and the thermal regime favours the presence of permafrost. ERT shows the lowest resistivity values in the lower part of the alluvial fan and a highly resistivity zone in the upper sector of the fan and in the debris cones. These large variations in resistivity mark the presence of a saline water wedge from the sea into the fan, reaching frozen ground conditions about 100 m inland. It can be shown that the volcano-hydrothermal activity only inhibits frost development very locally, with frozen ground conditions occurring about 100 m away. info:eu-repo/semantics/publishedVersion Article in Journal/Newspaper Antarc* Antarctica Bransfield Strait Deception Island permafrost South Shetland Islands wedge* Universidade de Lisboa: repositório.UL Bransfield Strait Deception Island ENVELOPE(-60.633,-60.633,-62.950,-62.950) Showa ENVELOPE(39.582,39.582,-69.004,-69.004) South Shetland Islands Geomorphology 225 57 68 |
institution |
Open Polar |
collection |
Universidade de Lisboa: repositório.UL |
op_collection_id |
ftunivlisboa |
language |
English |
topic |
Permafrost Geothermal Anomaly Active Volcano Deception Island South Shetlands Antarctica |
spellingShingle |
Permafrost Geothermal Anomaly Active Volcano Deception Island South Shetlands Antarctica Goyanes, G. Vieira, Goncalo Caselli, A. Cardoso, M. Marmy, A. Santos, F. Bernardo, I. Hauck, C. Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
topic_facet |
Permafrost Geothermal Anomaly Active Volcano Deception Island South Shetlands Antarctica |
description |
This study aims at understanding the spatial distribution and characteristics of the frozen and unfrozen terrain in an alluvial fan on Deception Island, which is an active strato-volcano located in the Bransfield Strait (South Shetland Islands)with recent eruptions in 1967, 1969 and 1970. The alluvial fan is dominated by debris-flow, run-off and rock fall processes and permafrost occurs in several parts in the vicinity of anomalous geothermal heat flux. The aim is to assess the ways volcanic activity controls permafrost development and associated geomorphic dynamics using shallow subsurface, surface and air temperature measurements as well as thaw depth and electrical resistivity tomography (ERT) surveys. Results showa temperature increasewith depth in the lower part of the fan reaching 13 °C at 0.80mdepth,without the presence of permafrost. The shallowborehole located at this site showed a stable thermal stratification all year-round, with only the upper 0.20 m reacting to meteorological forcing. In the upper part of the alluvial fan and debris cones, c. 100mfromthe coast, frozen ground is present at c. 0.70mdepth. There, the shallowborehole shows a good coupling with air temperatures and the thermal regime favours the presence of permafrost. ERT shows the lowest resistivity values in the lower part of the alluvial fan and a highly resistivity zone in the upper sector of the fan and in the debris cones. These large variations in resistivity mark the presence of a saline water wedge from the sea into the fan, reaching frozen ground conditions about 100 m inland. It can be shown that the volcano-hydrothermal activity only inhibits frost development very locally, with frozen ground conditions occurring about 100 m away. info:eu-repo/semantics/publishedVersion |
format |
Article in Journal/Newspaper |
author |
Goyanes, G. Vieira, Goncalo Caselli, A. Cardoso, M. Marmy, A. Santos, F. Bernardo, I. Hauck, C. |
author_facet |
Goyanes, G. Vieira, Goncalo Caselli, A. Cardoso, M. Marmy, A. Santos, F. Bernardo, I. Hauck, C. |
author_sort |
Goyanes, G. |
title |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
title_short |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
title_full |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
title_fullStr |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
title_full_unstemmed |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
title_sort |
local influences of geothermal anomalies on permafrost distribution in an active volcanic island (deception island, antarctica) |
publisher |
Elsevier |
publishDate |
2017 |
url |
http://hdl.handle.net/10451/27205 https://doi.org/10.1016/j.geomorph.2014.04.010 |
long_lat |
ENVELOPE(-60.633,-60.633,-62.950,-62.950) ENVELOPE(39.582,39.582,-69.004,-69.004) |
geographic |
Bransfield Strait Deception Island Showa South Shetland Islands |
geographic_facet |
Bransfield Strait Deception Island Showa South Shetland Islands |
genre |
Antarc* Antarctica Bransfield Strait Deception Island permafrost South Shetland Islands wedge* |
genre_facet |
Antarc* Antarctica Bransfield Strait Deception Island permafrost South Shetland Islands wedge* |
op_relation |
Geomorphology 225 (2014) 57–68 0169-555X http://hdl.handle.net/10451/27205 doi:10.1016/j.geomorph.2014.04.010 |
op_rights |
closedAccess |
op_doi |
https://doi.org/10.1016/j.geomorph.2014.04.010 |
container_title |
Geomorphology |
container_volume |
225 |
container_start_page |
57 |
op_container_end_page |
68 |
_version_ |
1766096898942304256 |