A proposed history of permafrost development in Labrador-Ungava
The recent history of mapping permafrost distribution in Labrador-Ungava is reviewed and an attempt is made to assess the accuracy of the most recent maps. Relationships between ground temperature and other environmental conditions are then discussed. These two introductory sections provide the basi...
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Les Presses de l’Université de Montréal
1979
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Online Access: | http://id.erudit.org/iderudit/1000360ar https://doi.org/10.7202/1000360ar |
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fterudit:oai:erudit.org:1000360ar 2023-05-15T16:37:03+02:00 A proposed history of permafrost development in Labrador-Ungava Ives, Jack D. 1979 http://id.erudit.org/iderudit/1000360ar https://doi.org/10.7202/1000360ar en eng Les Presses de l’Université de Montréal Érudit Géographie physique et Quaternaire vol. 33 no. 3-4 (1979) http://id.erudit.org/iderudit/1000360ar doi:10.7202/1000360ar Tous droits réservés © Les Presses de l’Université de Montréal, 1979 text 1979 fterudit https://doi.org/10.7202/1000360ar 2022-09-24T23:14:18Z The recent history of mapping permafrost distribution in Labrador-Ungava is reviewed and an attempt is made to assess the accuracy of the most recent maps. Relationships between ground temperature and other environmental conditions are then discussed. These two introductory sections provide the basis for the main objective of the paper. A hypothesis of permafrost development is elaborated and rests upon two considerations: (1) that much of Labrador-Ungava is underlain by permafrost which is in approximate equilibrium with present-day conditions and that its distribution is largely controlled by vegetation cover rather than regional variations in climate, and (2) that patches of relic permafrost have been found widely throughout the southern section of the peninsula. It is proposed that, following disintegration and melt of the last ice sheet, permafrost developed over wide areas before tree species were able to migrate northwards. As the forest cover-types began to occupy areas comparable to those so occupied today ground thermal characteristics changed. This was caused not only by the direct effects of forest invasion but by the impact of the forest on the winter snow cover. As conditions more nearly approached those prevailing today, degradation of permafrost set in and the present relic patches are air that remains of this process. The hypothesis is supported by recent progress in palynological and vegetational history studies. These demonstrate that a tundra phase existed for 1000 to 2000 or more years between the time of ice sheet disappearance and establishment of the forest cover. L’évolution du pergélisol au Labrador-Ungava : une hypothèse historique. Dans cet article, on retrace d’abord l’évolution récente de la cartographie de cette région, puis on tente de vérifier l’exactitude des dernières cartes produites. On discute ensuite des relations entre la température du sol et les diverses caractéristiques du milieu. À partir de ces prémisses, on élabore une hypothèse de l’évolution du pergélisol qui ... Text Ice Ice Sheet permafrost Tundra pergélisol Érudit.org (Université Montréal) Géographie physique et Quaternaire 33 3-4 233 244 |
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Open Polar |
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Érudit.org (Université Montréal) |
op_collection_id |
fterudit |
language |
English |
description |
The recent history of mapping permafrost distribution in Labrador-Ungava is reviewed and an attempt is made to assess the accuracy of the most recent maps. Relationships between ground temperature and other environmental conditions are then discussed. These two introductory sections provide the basis for the main objective of the paper. A hypothesis of permafrost development is elaborated and rests upon two considerations: (1) that much of Labrador-Ungava is underlain by permafrost which is in approximate equilibrium with present-day conditions and that its distribution is largely controlled by vegetation cover rather than regional variations in climate, and (2) that patches of relic permafrost have been found widely throughout the southern section of the peninsula. It is proposed that, following disintegration and melt of the last ice sheet, permafrost developed over wide areas before tree species were able to migrate northwards. As the forest cover-types began to occupy areas comparable to those so occupied today ground thermal characteristics changed. This was caused not only by the direct effects of forest invasion but by the impact of the forest on the winter snow cover. As conditions more nearly approached those prevailing today, degradation of permafrost set in and the present relic patches are air that remains of this process. The hypothesis is supported by recent progress in palynological and vegetational history studies. These demonstrate that a tundra phase existed for 1000 to 2000 or more years between the time of ice sheet disappearance and establishment of the forest cover. L’évolution du pergélisol au Labrador-Ungava : une hypothèse historique. Dans cet article, on retrace d’abord l’évolution récente de la cartographie de cette région, puis on tente de vérifier l’exactitude des dernières cartes produites. On discute ensuite des relations entre la température du sol et les diverses caractéristiques du milieu. À partir de ces prémisses, on élabore une hypothèse de l’évolution du pergélisol qui ... |
format |
Text |
author |
Ives, Jack D. |
spellingShingle |
Ives, Jack D. A proposed history of permafrost development in Labrador-Ungava |
author_facet |
Ives, Jack D. |
author_sort |
Ives, Jack D. |
title |
A proposed history of permafrost development in Labrador-Ungava |
title_short |
A proposed history of permafrost development in Labrador-Ungava |
title_full |
A proposed history of permafrost development in Labrador-Ungava |
title_fullStr |
A proposed history of permafrost development in Labrador-Ungava |
title_full_unstemmed |
A proposed history of permafrost development in Labrador-Ungava |
title_sort |
proposed history of permafrost development in labrador-ungava |
publisher |
Les Presses de l’Université de Montréal |
publishDate |
1979 |
url |
http://id.erudit.org/iderudit/1000360ar https://doi.org/10.7202/1000360ar |
genre |
Ice Ice Sheet permafrost Tundra pergélisol |
genre_facet |
Ice Ice Sheet permafrost Tundra pergélisol |
op_relation |
Géographie physique et Quaternaire vol. 33 no. 3-4 (1979) http://id.erudit.org/iderudit/1000360ar doi:10.7202/1000360ar |
op_rights |
Tous droits réservés © Les Presses de l’Université de Montréal, 1979 |
op_doi |
https://doi.org/10.7202/1000360ar |
container_title |
Géographie physique et Quaternaire |
container_volume |
33 |
container_issue |
3-4 |
container_start_page |
233 |
op_container_end_page |
244 |
_version_ |
1766027353528467456 |