Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research
Because of basal melting beneath the massive Antarctic ice sheet, permafrost probably comprises less than 25% of the Southern Circumpolar Region (c. ≥ 50°S latitude). Permafrost is pervasive in ice‐free areas of Antarctica and its offshore islands but is lacking in the sub‐Antarctic islands, except...
Published in: | Permafrost and Periglacial Processes |
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Online Access: | https://doi.org/10.1002/ppp.3430060105 |
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ftrepec:oai:RePEc:wly:perpro:v:6:y:1995:i:1:p:27-45 2023-05-15T13:59:51+02:00 Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research James G. Bockheim https://doi.org/10.1002/ppp.3430060105 unknown https://doi.org/10.1002/ppp.3430060105 article ftrepec https://doi.org/10.1002/ppp.3430060105 2020-12-04T13:31:03Z Because of basal melting beneath the massive Antarctic ice sheet, permafrost probably comprises less than 25% of the Southern Circumpolar Region (c. ≥ 50°S latitude). Permafrost is pervasive in ice‐free areas of Antarctica and its offshore islands but is lacking in the sub‐Antarctic islands, except possibly at the higher elevations. Based on limited data, the thickness of permafrost ranges from 100 to 1000m in ice‐free areas of Antarctica. The thickness of the active layer ranges between 50 and 150 cm in the Antarctic islands and maritime East Antarctica and 15 and 50 cm in interior Antarctica. Ground ice is restricted to rock glaciers and ice wedges; the rock glaciers, palsa and thermokarst reported in some areas originate from ice‐cored drift and not permafrost. Active and inactive patterned ground occurs throughout the region. Whereas sorted circles, nets, and stripes are common in the Antarctic islands and in maritime East Antarctica, ice‐ and sand‐wedge polygons are prevalent in ice‐free valleys of Antarctica. Altiplanation terraces may exist in the Antarctic islands and in maritime East Antarctica; however, landforms in interior Antarctica are controlled more by salt weathering than by cryogenic processes. Based‐on the presence of inactive rock glaciers, gelifluction lobes, and large‐scale patterned‐ground features, permafrost was probably present in the sub‐Antarctic islands during the last glaciation. Recommendations are made for future work in the region. Comme la base de la calotte glaciaire antarctique se trouve au point de fusion, le pergélisol occupe probablement moins de 25% de la région circumpolaire antarctique en entendant par là, la zone qui se trouve à une latitude supérieure à 50°S. Le pergélisol est continu dans les régions libres de glace de l'Antarctique et dans les ǐles voisines; il est absent dans les ǐles subantarctiques, sauf peut‐ětre en altitude. Sur la base de données limitées, l'épaisseur du pergélisol varie entre 100 et 1.000 m dans les régions libres des glace de l'Antarctique. L'épaisseur de la couche active varie entre 50 et 150cm dans les ǐles et dans l'Est maritime de l'Antarctique et entre 15 et 50cm à l'interieur de l'Antarctique. La glace de sol est limitée aux glaciers rocheux et aux coins de glace; les glaciers rocheus, les palses et le thermokarst mentionnés dans quelques régions troubent leur origine dans la présence de glace glaciaire enfouie et non dans celle de glace apparue dans le sol. Des sols polygonaux actifs et non actifs existent dans toute la région. Article in Journal/Newspaper Antarc* Antarctic Antarctica Antarctique* East Antarctica Ice Ice Sheet palsa palse* permafrost Thermokarst wedge* pergélisol RePEc (Research Papers in Economics) Antarctic East Antarctica The Antarctic Permafrost and Periglacial Processes 6 1 27 45 |
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Open Polar |
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RePEc (Research Papers in Economics) |
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unknown |
description |
Because of basal melting beneath the massive Antarctic ice sheet, permafrost probably comprises less than 25% of the Southern Circumpolar Region (c. ≥ 50°S latitude). Permafrost is pervasive in ice‐free areas of Antarctica and its offshore islands but is lacking in the sub‐Antarctic islands, except possibly at the higher elevations. Based on limited data, the thickness of permafrost ranges from 100 to 1000m in ice‐free areas of Antarctica. The thickness of the active layer ranges between 50 and 150 cm in the Antarctic islands and maritime East Antarctica and 15 and 50 cm in interior Antarctica. Ground ice is restricted to rock glaciers and ice wedges; the rock glaciers, palsa and thermokarst reported in some areas originate from ice‐cored drift and not permafrost. Active and inactive patterned ground occurs throughout the region. Whereas sorted circles, nets, and stripes are common in the Antarctic islands and in maritime East Antarctica, ice‐ and sand‐wedge polygons are prevalent in ice‐free valleys of Antarctica. Altiplanation terraces may exist in the Antarctic islands and in maritime East Antarctica; however, landforms in interior Antarctica are controlled more by salt weathering than by cryogenic processes. Based‐on the presence of inactive rock glaciers, gelifluction lobes, and large‐scale patterned‐ground features, permafrost was probably present in the sub‐Antarctic islands during the last glaciation. Recommendations are made for future work in the region. Comme la base de la calotte glaciaire antarctique se trouve au point de fusion, le pergélisol occupe probablement moins de 25% de la région circumpolaire antarctique en entendant par là, la zone qui se trouve à une latitude supérieure à 50°S. Le pergélisol est continu dans les régions libres de glace de l'Antarctique et dans les ǐles voisines; il est absent dans les ǐles subantarctiques, sauf peut‐ětre en altitude. Sur la base de données limitées, l'épaisseur du pergélisol varie entre 100 et 1.000 m dans les régions libres des glace de l'Antarctique. L'épaisseur de la couche active varie entre 50 et 150cm dans les ǐles et dans l'Est maritime de l'Antarctique et entre 15 et 50cm à l'interieur de l'Antarctique. La glace de sol est limitée aux glaciers rocheux et aux coins de glace; les glaciers rocheus, les palses et le thermokarst mentionnés dans quelques régions troubent leur origine dans la présence de glace glaciaire enfouie et non dans celle de glace apparue dans le sol. Des sols polygonaux actifs et non actifs existent dans toute la région. |
format |
Article in Journal/Newspaper |
author |
James G. Bockheim |
spellingShingle |
James G. Bockheim Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research |
author_facet |
James G. Bockheim |
author_sort |
James G. Bockheim |
title |
Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research |
title_short |
Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research |
title_full |
Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research |
title_fullStr |
Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research |
title_full_unstemmed |
Permafrost distribution in the southern circumpolar region and its relation to the environment: A review and recommendations for further research |
title_sort |
permafrost distribution in the southern circumpolar region and its relation to the environment: a review and recommendations for further research |
url |
https://doi.org/10.1002/ppp.3430060105 |
geographic |
Antarctic East Antarctica The Antarctic |
geographic_facet |
Antarctic East Antarctica The Antarctic |
genre |
Antarc* Antarctic Antarctica Antarctique* East Antarctica Ice Ice Sheet palsa palse* permafrost Thermokarst wedge* pergélisol |
genre_facet |
Antarc* Antarctic Antarctica Antarctique* East Antarctica Ice Ice Sheet palsa palse* permafrost Thermokarst wedge* pergélisol |
op_relation |
https://doi.org/10.1002/ppp.3430060105 |
op_doi |
https://doi.org/10.1002/ppp.3430060105 |
container_title |
Permafrost and Periglacial Processes |
container_volume |
6 |
container_issue |
1 |
container_start_page |
27 |
op_container_end_page |
45 |
_version_ |
1766268749402341376 |