Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer
Abstract Ice wedge polygons on steep slopes have generally been described as being covered by periglacial sediments and, typically, the active layer on slopes becomes mobile during thaw periods, which can lead to solifluction. In West Greenland close to the ice margin, however, the active layer and...
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Online Access: | http://dx.doi.org/10.1002/ppp.2181 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2181 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2181 |
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crwiley:10.1002/ppp.2181 2024-06-02T08:07:30+00:00 Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer Schwarzkopf, Katharina Seitz, Steffen Fritz, Michael Scholten, Thomas Kühn, Peter 2023 http://dx.doi.org/10.1002/ppp.2181 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2181 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2181 en eng Wiley http://creativecommons.org/licenses/by-nc-nd/4.0/ Permafrost and Periglacial Processes volume 34, issue 2, page 194-207 ISSN 1045-6740 1099-1530 journal-article 2023 crwiley https://doi.org/10.1002/ppp.2181 2024-05-03T11:05:57Z Abstract Ice wedge polygons on steep slopes have generally been described as being covered by periglacial sediments and, typically, the active layer on slopes becomes mobile during thaw periods, which can lead to solifluction. In West Greenland close to the ice margin, however, the active layer and ice wedge polygons are stable despite their occurrence on steep slopes with inclinations of ≥30°. We conducted a soil survey (including sampling for soil analyses and radiocarbon dating) in the Umimmalissuaq valley and installed a field station ~4 km east of the current ice margin to monitor soil temperature and water tension at depths of 10, 20 and 35 cm of the active layer on a steep, north‐facing slope in the middle of an ice wedge polygon from 2009 to 2015. Thawing and freezing periods lasted between 2 and 3 months and the active layer was usually completely frozen from November to April. We observed simultaneous and complete water saturation at all three depths of the active layer in one summer for 1 day. The amount of water in the active layer apparently was not enough to trigger solifluction during the summer thaw, even at slope inclinations above 30°. In addition, the dense shrub tundra absorbs most of the water during periods between thawing and freezing, which further stabilizes the slope. This process, together with the dry and continental climate caused by katabatic winds combined with no or limited frost heave, plays a crucial role in determining the stability of these slopes and can explain the presence of large‐scale stable ice wedge polygon networks in organic matter‐rich permafrost, which is about 5,000 years old. This study underlines the importance of soil hydrodynamics and local climate regime for landscape stability and differing intensities of solifluction processes in areas with strong geomorphological gradients and rising air temperatures. Article in Journal/Newspaper Greenland Ice permafrost Permafrost and Periglacial Processes Tundra wedge* Wiley Online Library Greenland Permafrost and Periglacial Processes 34 2 194 207 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Ice wedge polygons on steep slopes have generally been described as being covered by periglacial sediments and, typically, the active layer on slopes becomes mobile during thaw periods, which can lead to solifluction. In West Greenland close to the ice margin, however, the active layer and ice wedge polygons are stable despite their occurrence on steep slopes with inclinations of ≥30°. We conducted a soil survey (including sampling for soil analyses and radiocarbon dating) in the Umimmalissuaq valley and installed a field station ~4 km east of the current ice margin to monitor soil temperature and water tension at depths of 10, 20 and 35 cm of the active layer on a steep, north‐facing slope in the middle of an ice wedge polygon from 2009 to 2015. Thawing and freezing periods lasted between 2 and 3 months and the active layer was usually completely frozen from November to April. We observed simultaneous and complete water saturation at all three depths of the active layer in one summer for 1 day. The amount of water in the active layer apparently was not enough to trigger solifluction during the summer thaw, even at slope inclinations above 30°. In addition, the dense shrub tundra absorbs most of the water during periods between thawing and freezing, which further stabilizes the slope. This process, together with the dry and continental climate caused by katabatic winds combined with no or limited frost heave, plays a crucial role in determining the stability of these slopes and can explain the presence of large‐scale stable ice wedge polygon networks in organic matter‐rich permafrost, which is about 5,000 years old. This study underlines the importance of soil hydrodynamics and local climate regime for landscape stability and differing intensities of solifluction processes in areas with strong geomorphological gradients and rising air temperatures. |
format |
Article in Journal/Newspaper |
author |
Schwarzkopf, Katharina Seitz, Steffen Fritz, Michael Scholten, Thomas Kühn, Peter |
spellingShingle |
Schwarzkopf, Katharina Seitz, Steffen Fritz, Michael Scholten, Thomas Kühn, Peter Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer |
author_facet |
Schwarzkopf, Katharina Seitz, Steffen Fritz, Michael Scholten, Thomas Kühn, Peter |
author_sort |
Schwarzkopf, Katharina |
title |
Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer |
title_short |
Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer |
title_full |
Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer |
title_fullStr |
Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer |
title_full_unstemmed |
Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer |
title_sort |
ice wedge polygon stability on steep slopes in west greenland related to temperature and moisture dynamics of the active layer |
publisher |
Wiley |
publishDate |
2023 |
url |
http://dx.doi.org/10.1002/ppp.2181 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2181 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2181 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice permafrost Permafrost and Periglacial Processes Tundra wedge* |
genre_facet |
Greenland Ice permafrost Permafrost and Periglacial Processes Tundra wedge* |
op_source |
Permafrost and Periglacial Processes volume 34, issue 2, page 194-207 ISSN 1045-6740 1099-1530 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1002/ppp.2181 |
container_title |
Permafrost and Periglacial Processes |
container_volume |
34 |
container_issue |
2 |
container_start_page |
194 |
op_container_end_page |
207 |
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1800752582366330880 |