Half a century of discontinuous permafrost persistence and degradation in western Canada
Abstract Long‐term field studies of permafrost change are needed to validate predictive models but few are possible because of a paucity of direct observations prior to the late 1970s. To help fill this knowledge gap, we resurveyed a transect of 68 sites, originally investigated in 1962, to evaluate...
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crwiley:10.1002/ppp.2017 2024-09-30T14:36:13+00:00 Half a century of discontinuous permafrost persistence and degradation in western Canada Holloway, Jean E. Lewkowicz, Antoni G. Government of Canada Natural Sciences and Engineering Research Council of Canada University of Ottawa Royal Canadian Geographical Society W. Garfield Weston Foundation 2019 http://dx.doi.org/10.1002/ppp.2017 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2017 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2017 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Permafrost and Periglacial Processes volume 31, issue 1, page 85-96 ISSN 1045-6740 1099-1530 journal-article 2019 crwiley https://doi.org/10.1002/ppp.2017 2024-09-03T04:26:21Z Abstract Long‐term field studies of permafrost change are needed to validate predictive models but few are possible because of a paucity of direct observations prior to the late 1970s. To help fill this knowledge gap, we resurveyed a transect of 68 sites, originally investigated in 1962, to evaluate change in the isolated patches and sporadic discontinuous permafrost zones between Keg River, Alberta (57.8°N) and Hay River, Northwest Territories (60.8°N). The goal was to establish the degree of permafrost degradation due to approximately 2°C of regional climate warming over the intervening 55 years, compounded at some sites by forest fire. By 2017–2018, permafrost had degraded at 36% of the 44 sites which exhibited it in 1962, but had persisted at a minimum of 50% with a further 14% potentially retaining permafrost. This is much less degradation than reported for a 1988–1989 survey of the same transect. Permafrost was maintained under thicker organic layers (86% > 40 cm) and at the majority of sites with fine‐grained substrates, while degradation occurred preferentially at sites with coarse soils and thinner organic layers. Forest fire did not enhance the degree of permafrost loss, but greater frost table depths were observed at some burned locations. This study demonstrates that while the trajectory of change is towards permafrost loss, thin permafrost in the discontinuous zone can be persistent, even when disturbed. It also underlines the importance of considering the range of landscape types when projecting the rate of future permafrost thaw. Article in Journal/Newspaper Hay River Northwest Territories permafrost Permafrost and Periglacial Processes Wiley Online Library Northwest Territories Canada Hay River ENVELOPE(-115.847,-115.847,60.787,60.787) Keg River ENVELOPE(-117.636,-117.636,57.750,57.750) Permafrost and Periglacial Processes 31 1 85 96 |
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Open Polar |
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Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract Long‐term field studies of permafrost change are needed to validate predictive models but few are possible because of a paucity of direct observations prior to the late 1970s. To help fill this knowledge gap, we resurveyed a transect of 68 sites, originally investigated in 1962, to evaluate change in the isolated patches and sporadic discontinuous permafrost zones between Keg River, Alberta (57.8°N) and Hay River, Northwest Territories (60.8°N). The goal was to establish the degree of permafrost degradation due to approximately 2°C of regional climate warming over the intervening 55 years, compounded at some sites by forest fire. By 2017–2018, permafrost had degraded at 36% of the 44 sites which exhibited it in 1962, but had persisted at a minimum of 50% with a further 14% potentially retaining permafrost. This is much less degradation than reported for a 1988–1989 survey of the same transect. Permafrost was maintained under thicker organic layers (86% > 40 cm) and at the majority of sites with fine‐grained substrates, while degradation occurred preferentially at sites with coarse soils and thinner organic layers. Forest fire did not enhance the degree of permafrost loss, but greater frost table depths were observed at some burned locations. This study demonstrates that while the trajectory of change is towards permafrost loss, thin permafrost in the discontinuous zone can be persistent, even when disturbed. It also underlines the importance of considering the range of landscape types when projecting the rate of future permafrost thaw. |
author2 |
Government of Canada Natural Sciences and Engineering Research Council of Canada University of Ottawa Royal Canadian Geographical Society W. Garfield Weston Foundation |
format |
Article in Journal/Newspaper |
author |
Holloway, Jean E. Lewkowicz, Antoni G. |
spellingShingle |
Holloway, Jean E. Lewkowicz, Antoni G. Half a century of discontinuous permafrost persistence and degradation in western Canada |
author_facet |
Holloway, Jean E. Lewkowicz, Antoni G. |
author_sort |
Holloway, Jean E. |
title |
Half a century of discontinuous permafrost persistence and degradation in western Canada |
title_short |
Half a century of discontinuous permafrost persistence and degradation in western Canada |
title_full |
Half a century of discontinuous permafrost persistence and degradation in western Canada |
title_fullStr |
Half a century of discontinuous permafrost persistence and degradation in western Canada |
title_full_unstemmed |
Half a century of discontinuous permafrost persistence and degradation in western Canada |
title_sort |
half a century of discontinuous permafrost persistence and degradation in western canada |
publisher |
Wiley |
publishDate |
2019 |
url |
http://dx.doi.org/10.1002/ppp.2017 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2017 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2017 |
long_lat |
ENVELOPE(-115.847,-115.847,60.787,60.787) ENVELOPE(-117.636,-117.636,57.750,57.750) |
geographic |
Northwest Territories Canada Hay River Keg River |
geographic_facet |
Northwest Territories Canada Hay River Keg River |
genre |
Hay River Northwest Territories permafrost Permafrost and Periglacial Processes |
genre_facet |
Hay River Northwest Territories permafrost Permafrost and Periglacial Processes |
op_source |
Permafrost and Periglacial Processes volume 31, issue 1, page 85-96 ISSN 1045-6740 1099-1530 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/ppp.2017 |
container_title |
Permafrost and Periglacial Processes |
container_volume |
31 |
container_issue |
1 |
container_start_page |
85 |
op_container_end_page |
96 |
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1811639339426250752 |