Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica)
Autor(a) principal: | |
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Data de Publicação: | 2014 |
Outros Autores: | , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10451/27205 |
Resumo: | 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. |
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Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica)PermafrostGeothermal AnomalyActive VolcanoDeception IslandSouth ShetlandsAntarcticaThis 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.ElsevierRepositório da Universidade de LisboaGoyanes, G.Vieira, GoncaloCaselli, A.Cardoso, M.Marmy, A.Santos, F.Bernardo, I.Hauck, C.2017-03-17T10:58:07Z20142014-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10451/27205engGeomorphology 225 (2014) 57–680169-555X10.1016/j.geomorph.2014.04.010metadata only accessinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-08T16:17:53Zoai:repositorio.ul.pt:10451/27205Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:43:41.023646Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
title |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) |
spellingShingle |
Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica) Goyanes, G. Permafrost Geothermal Anomaly Active Volcano Deception Island South Shetlands 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) |
author |
Goyanes, G. |
author_facet |
Goyanes, G. Vieira, Goncalo Caselli, A. Cardoso, M. Marmy, A. Santos, F. Bernardo, I. Hauck, C. |
author_role |
author |
author2 |
Vieira, Goncalo Caselli, A. Cardoso, M. Marmy, A. Santos, F. Bernardo, I. Hauck, C. |
author2_role |
author author author author author author author |
dc.contributor.none.fl_str_mv |
Repositório da Universidade de Lisboa |
dc.contributor.author.fl_str_mv |
Goyanes, G. Vieira, Goncalo Caselli, A. Cardoso, M. Marmy, A. Santos, F. Bernardo, I. Hauck, C. |
dc.subject.por.fl_str_mv |
Permafrost Geothermal Anomaly Active Volcano Deception Island South Shetlands Antarctica |
topic |
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. |
publishDate |
2014 |
dc.date.none.fl_str_mv |
2014 2014-01-01T00:00:00Z 2017-03-17T10:58:07Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10451/27205 |
url |
http://hdl.handle.net/10451/27205 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Geomorphology 225 (2014) 57–68 0169-555X 10.1016/j.geomorph.2014.04.010 |
dc.rights.driver.fl_str_mv |
metadata only access info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
metadata only access |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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