CGRG Bibliography of Canadian Geomorphology
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Author : Godin, E.; Gray, G.T.; Masse, J.; and Fortier, D.
Date : 2008.
Title : Evolution of the thermal regime of permafrost in Gaspésie, Southern Quebec, Canada over the last 30 years.
Publication : International Arctic Change 2008 Conference. December 9-12, 2008. Quebec City, Quebec.
Issue : Conference Programme and Abstracts
Page(s) : 224.
Abstract
The Parc National de la Gaspésie at the northern extremity of the Appalachian Mountain Range in southern Québec exhibits multiple contemporary periglacial phenomena associated withboth contemporary and relic permafrost. Its relative accessibility allowed a long term study of the thermal regime of a 50 -60 m thick permafrost body beneath the 1270 m high summit of Mont Jacques Cartier Data from a 30 m long string of thermistors, installed in 1977 ina drill-hole in bedrock, beneath a 3 m thick layer of felsenmeers (Gray and Brown, 1979, 1982) has been since obtained on an almost annual basis. In 2007 a data-logger was connected to 7 of these thermistors, in an effort to provide detailed diurnal and seasonal geothermal data. Monitoring of the thermal regime of this permafrost body offers an excellent opportunity to detect the presence and propagation of warming, or cooling trends from the surface downwards towards the base of the permafrost, and to predict its long-term evolution. Gray and Brown (1979) evaluated the depth of the active layer to be around 5.7 m in 1977,with a permafrost thickness of 45 -60 m, based on extrapolation from the thermal gradient. Our preliminary analysis indicates that the active layer is now deeper and that the temperature of the permafrost has shown a general increase in temperature of 0.5°C down to a depth of 23 m. However at a depth of 26 m no change is as yet detectable. It appears from a preliminary analysis of the data between depths of 14 and 23 m, that both cooling and warming trends on a decennial or five year wavelength can be observed. An analysis of the historical regional air temperature recorded by Environment Canada and local air temperature measured by the staff of the Gaspésie National Park will be used to explore the thermal response of the permafrost in the last decades. However, since the permafrost responds not only to air temperature changes, but very much to changes in snow cover, it is essential that future monitoring of the geothermal regime be augmented by surface climatic and snow cover data. Such installations are being planned in the context of this study.
Bibliography of Canadian Geomorphology