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TitleThermal state of permafrost in North America - a contribution to the International Polar Year
AuthorSmith, 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
Year2010
Alt SeriesEarth Sciences Sector, Contribution Series 20090343
Documentserial
Lang.English
Mediapaper; on-line; digital
ProvinceBritish Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut
NTS1; 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
AreaAlaska; Canada; United States
Lat/Long WENS-164.0000 -50.0000 90.0000 41.7500
Subjectssurficial geology/geomorphology; environmental geology; permafrost; freezing ground; ground ice; ground temperatures; thermal analyses; environmental studies; environmental impacts; climate change
Illustrationslocation maps; tables; graphs; images
ProgramEarth Science for National Scale Characterization of Climate Change Impacts on Canada's Landmass, Climate Change Geoscience
AbstractA 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