Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada
Abstract Near‐surface wedges of massive ice commonly outline polygons in tundra lowlands, but such polygons have been difficult to identify on hillslopes because soil movement flattens the ridges and infills the troughs that form beside and above the ice wedges. Over the past three decades, the acti...
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crwiley:10.1002/ppp.2113 2024-06-23T07:49:59+00:00 Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada Burn, Christopher R. Lewkowicz, Antoni G. Wilson, M. Alice Parks Canada Aurora Research Institute Natural Resources Canada Natural Sciences and Engineering Research Council of Canada 2021 http://dx.doi.org/10.1002/ppp.2113 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2113 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2113 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Permafrost and Periglacial Processes volume 32, issue 2, page 261-276 ISSN 1045-6740 1099-1530 journal-article 2021 crwiley https://doi.org/10.1002/ppp.2113 2024-06-13T04:21:02Z Abstract Near‐surface wedges of massive ice commonly outline polygons in tundra lowlands, but such polygons have been difficult to identify on hillslopes because soil movement flattens the ridges and infills the troughs that form beside and above the ice wedges. Over the past three decades, the active layer has thickened near the western Arctic coast of Canada and consequent thawing of ice wedges has been detected by remote sensing for flat terrain but not, generally, on hillslopes. Annual field surveys (1996–2018) at the Illisarvik field site of thaw depth and ground surface elevation show the mean subsidence rate above hillslope ice wedges has been up to 32 mm a −1 since thaw depth reached the ice‐wedge tops in 2007. Annual mean ground temperatures at the site are about −3.0°C beneath late‐winter snow depths characteristic of the ice‐wedge troughs but about −5.3°C under conditions of the intervening polygons. The rate of thaw subsidence is high for natural, subaerial disturbances because meltwater from the ice wedges runs off downslope. The rate is constant, because the thickness of seasonally thawed ground above the ice wedges and the ice content of the ground remain the same while the troughs develop. Observations of changes in surface elevation in northern Banks Island between the late 1970s and 2019 show troughs on hillslopes where none was previously visible. Development of these troughs creates regional thermokarst landscapes, distinct from the widely recognized results of thawing relict glacier ice, that are now widespread over Canada's western Arctic coastlands. Recognition of ice‐wedge occurrence and accelerated thaw subsidence on hillslopes is important in the design of infrastructure proposed for construction in rolling permafrost terrain. Article in Journal/Newspaper Arctic Banks Island glacier* Ice permafrost Permafrost and Periglacial Processes Thermokarst Tundra wedge* Wiley Online Library Arctic Canada Permafrost and Periglacial Processes 32 2 261 276 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Near‐surface wedges of massive ice commonly outline polygons in tundra lowlands, but such polygons have been difficult to identify on hillslopes because soil movement flattens the ridges and infills the troughs that form beside and above the ice wedges. Over the past three decades, the active layer has thickened near the western Arctic coast of Canada and consequent thawing of ice wedges has been detected by remote sensing for flat terrain but not, generally, on hillslopes. Annual field surveys (1996–2018) at the Illisarvik field site of thaw depth and ground surface elevation show the mean subsidence rate above hillslope ice wedges has been up to 32 mm a −1 since thaw depth reached the ice‐wedge tops in 2007. Annual mean ground temperatures at the site are about −3.0°C beneath late‐winter snow depths characteristic of the ice‐wedge troughs but about −5.3°C under conditions of the intervening polygons. The rate of thaw subsidence is high for natural, subaerial disturbances because meltwater from the ice wedges runs off downslope. The rate is constant, because the thickness of seasonally thawed ground above the ice wedges and the ice content of the ground remain the same while the troughs develop. Observations of changes in surface elevation in northern Banks Island between the late 1970s and 2019 show troughs on hillslopes where none was previously visible. Development of these troughs creates regional thermokarst landscapes, distinct from the widely recognized results of thawing relict glacier ice, that are now widespread over Canada's western Arctic coastlands. Recognition of ice‐wedge occurrence and accelerated thaw subsidence on hillslopes is important in the design of infrastructure proposed for construction in rolling permafrost terrain. |
author2 |
Parks Canada Aurora Research Institute Natural Resources Canada Natural Sciences and Engineering Research Council of Canada |
format |
Article in Journal/Newspaper |
author |
Burn, Christopher R. Lewkowicz, Antoni G. Wilson, M. Alice |
spellingShingle |
Burn, Christopher R. Lewkowicz, Antoni G. Wilson, M. Alice Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada |
author_facet |
Burn, Christopher R. Lewkowicz, Antoni G. Wilson, M. Alice |
author_sort |
Burn, Christopher R. |
title |
Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada |
title_short |
Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada |
title_full |
Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada |
title_fullStr |
Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada |
title_full_unstemmed |
Long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western Arctic Canada |
title_sort |
long‐term field measurements of climate‐induced thaw subsidence above ice wedges on hillslopes, western arctic canada |
publisher |
Wiley |
publishDate |
2021 |
url |
http://dx.doi.org/10.1002/ppp.2113 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2113 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2113 |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic Banks Island glacier* Ice permafrost Permafrost and Periglacial Processes Thermokarst Tundra wedge* |
genre_facet |
Arctic Banks Island glacier* Ice permafrost Permafrost and Periglacial Processes Thermokarst Tundra wedge* |
op_source |
Permafrost and Periglacial Processes volume 32, issue 2, page 261-276 ISSN 1045-6740 1099-1530 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/ppp.2113 |
container_title |
Permafrost and Periglacial Processes |
container_volume |
32 |
container_issue |
2 |
container_start_page |
261 |
op_container_end_page |
276 |
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1802640722975784960 |