CGRG Bibliography of Canadian Geomorphology
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Author : French, H.M.; and Egorov, I.E.
Date : 1998
Title : Twentieth Century variations in the southern limit of permafrost near Thompson, northern Manitoba, Canada.
Publication : Permafrost, Seventh International Conference, June 23-27, Yellowknife, Canada. Edited by: A.G. Lewkowicz and M. Allard. Université Laval, Centre d'études nordiques, Collection Nordicana.
Issue : 57:
Page(s) : 297-304.
Abstract
Air temperatures for varying periods from 1910-1993, recorded from a number of weather stations in Manitoba, have been analyzed together with ground temperature data collected from 4 closely spaced sites at Thompson between 1969-1976. The predicted mean annual air temperature for Thompson has increased over the period 1910-1993 by approximately 0.5 -1.0°C. Geocryological parameters, such as predicted freezing and thawing indices, indicate that during this 80+ yr period, short-term (i.e. decade-duration) permafrost must have formed and degraded at the southern limit of sporadic permafrost in response to short term climatic fluctuations. This may explain why the marginal permafrost at one of the Thompson sites degraded during the 1968-197676 period and the two non permafrost sites showed slight warming. New residential buildings, constructed in the 1990's on permafrost-free subdivision lots which initially possessed permafrost in the 1960's, are a second indication that permafrost bodies are degrading under present conditions.
Bibliography of Canadian Geomorphology