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TitreThermal state of permafrost in North America - a contribution to the International Polar Year
AuteurSmith, S L; Romanovsky, V E; Lewkowicz, A G; Burn, C R; Allard, M; Clow, G D; Yoshikawa, K; Throop, J
SourcePermafrost and Periglacial Processes vol. 21, 2010 p. 117-135, https://doi.org/10.1002/ppp.690
Année2010
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090343
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1002/ppp.690
Mediapapier; en ligne; numérique
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-164.0000 -50.0000 90.0000 41.7500
Sujetspergélisol; congélation du sol; glace fossile; températures au sol; analyses thermiques; etudes de l'environnement; effets sur l'environnement; Changement climatique; géologie des dépôts meubles/géomorphologie; géologie de l'environnement
Illustrationslocation maps; tables; graphs; images
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)
A snapshot of the thermal state of permafrost in northern North America during the International Polar Year (IPY) was developed using ground temperature data collected from350 boreholes.More than half thesewere established during IPY to enhance the network in sparsely monitored regions. The measurement sites span a diverse range of ecoclimatic and geological conditions across the continent and are at various elevations within the Cordillera. The ground temperatures within the discontinuous permafrost zone are generally above -3°C, and range down to -15°C in the continuous zone. Ground temperature envelopes vary according to substrate, with shallow depths of zero annual amplitude for peat and mineral soils, and much greater depths for bedrock. New monitoring sites in the mountains of southern and central Yukon suggest that permafrost may be limited in extent. In concert with regional air temperatures, permafrost has generally been warming across North America for the past several decades, as indicated by measurements from the western Arctic since the 1970s and from parts of eastern Canada since the early 1990s. The rates of ground warming have been variable, but are generally greater north of the treeline. Latent heat effects in the southern discontinuous zone dominate the permafrost thermal regime close to 0°C and allow permafrost to persist under a warming climate. Consequently, the spatial diversity of permafrost thermal conditions is decreasing over time.
GEOSCAN ID261528