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TitlePermafrost and peatland evolution in the northern Hudson Bay Lowlands, Manitoba
AuthorDyke, L D; Sladen, W E
SourceArctic vol. 63, no. 4, 2010 p. 429-441, Open Access logo Open Access
Alt SeriesEarth Sciences Sector, Contribution Series 20090273
PublisherThe Arctic Institute of North America
Mediapaper; on-line; digital
File formatpdf
NTS54F; 54K
AreaNorthern Hudson Bay Lowland; Wapusk National Park
Lat/Long WENS-94.0000 -92.5000 59.0000 57.0000
Subjectssurficial geology/geomorphology; Nature and Environment; permafrost; freezing ground; ground ice; ground temperatures; fens; peat; peatlands; peat analyses
Illustrationslocation maps; photographs; cross-sections; tables; graphs; plots
ProgramClimate Change Geoscience
Released2010 12 03
AbstractThe northern Hudson Bay lowland includes the largest area of frozen peat plateau bog in Canada. Polar bear denning habitat, caribou forage, carbon storage, and wetland drainage control provided by peat plateaus will be affected if post-Little Ice Age warming continues. Mapping and thermal modeling of frozen peat plateau stability indicate that permafrost peatlands are stable at a mean annual air temperature as warm as -3.5°C. In the peat plateaus of the northern lowland, permafrost can be absent at the peat plateau margins where peat plateaus border fens or lakes. Here, insulating snow accumulations permit thawed conditions at mean annual air temperatures colder than -3.5°C. Continued warming will result in expansion of thawed zones, subsidence at plateau margins, and even collapse of plateau surfaces, resulting in conversion to fen. This process has already occurred across north-central Manitoba, Saskatchewan, and Alberta since the end of the Little Ice Age, and there are signs that it is extending into the northern Hudson Bay lowland. Wave erosion of subsiding plateau borders at lake shorelines is also resulting in loss of peat plateau bog.

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