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TitreThe thermal state of permafrost in Canada - results from the International Polar Year
AuteurSmith, S L; Lewkowicz, A G; Burn, C R; Allard, M; Throop, J L
SourceThermal state of frozen ground in a changing climate during the IPY, abstracts from the Third European Conference on Permafrost; par Mertes, J R (éd.); Christiansen, H H (éd.); Etzelmüller, B (éd.); 2010 p. 24
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090436
Réunion3rd European Conference on Permafrost (EUCOPIII); Longyearbyen Svalbard; NO; juin 14-18, 2010
ProvinceColombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon; Nunavut
SNRC1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Lat/Long OENS-141.0000 -50.0000 90.0000 41.7500
Sujetspergélisol; glace fossile; congélation du sol; types de terrain; analyse de terrains; analyses thermiques; températures au sol; géologie des dépôts meubles/géomorphologie
ProgrammeLes sciences de la Terre à l'appui de la caractérisation, à l'échelle nationale, des impacts des changements climatiques sur la masse continentale canadienne, Géosciences de changements climatiques
Résumé(disponible en anglais seulement)
The International Polar Year (IPY) provided the op-portunity for the Canadian permafrost community to conduct a coordinated program of permafrost obser-vations in order to define present permafrost condi-tions and their spatial and temporal variability. Can-ada¿s contribution to the multinational Thermal State of Permafrost project examines the ongoing impacts of climate change on permafrost conditions.
The Canadian permafrost monitoring network cur-rently consists of about 170 sites, with almost half of these established during the IPY to address geo-graphical gaps such as the eastern Arctic and the mountains of the Yukon Territory. The measurement sites span a diverse range of ecoclimatic and geo-logical conditions across northern Canada. An up-dated snapshot of the thermal state of permafrost was developed that indicates permafrost tempera-tures range from warmer than -2.5°C in the discon-tinuous zone to as cold as -15°C in the continuous zone (Table 1).
Ground temperature records 20 to 30 years long, available for a number of sites, indicate that perma-frost was generally warmer during IPY than the av-erage ground temperature for the entire record. In concert with regional air temperatures, permafrost has been warming across Canada for the past several decades with later warming occurring (since the early 1990s) in the eastern Arctic. Rates of perma-frost temperature increase are variable and are gen-erally greater in colder permafrost north of treeline where the upper 15 m of permafrost has warmed by up to 0.1°C per year. Latent heat effects in the southern discontinuous zone dominate the perma-frost thermal regime close to 0°C and allow perma-frost to persist for decades under a warming climate. Consequently, the spatial diversity of permafrost thermal conditions is decreasing over time.
The snapshot of permafrost thermal state generated by this project provides an improved baseline against which change can be measured. Essential in-formation has been generated for improved assess-ments of climate change impacts and predictions of future conditions. The project has also provided in-formation that can be utilized for: engineering de-sign of northern infrastructure; informed landuse planning decisions; development of adaptation strategies to deal with climate change.