Lateral Variations of Ground Temperatures along Linear Disturbances in the Peatlands in the Regions of Discontinuous Permafrost
Abstract ID#: 34844
Michael Braverman1 & William L Quinton2
1INSPEC-SOL Inc, 651 Colby Drive, Waterloo, On N2V 1C2
Phone: 519 725-9328 Fax: 519 884-5256, Email: mbraverman@inspecsol.com
2Cold Regions Research Centre, Wilfrid Laurier University 75 University Avenue W Waterloo, ON Phone: 519-884-0710 ext. 3281, Email: wquinton@wlu.ca
In subarctic peatlands permafrost is found under peat plateaus, while fens and flat bogs remain permafrost free, thus creating heat source. In stable environment permafrost and permafrost free terrain are in thermal equilibrium, which is affected just by climatic fluctuations. At the same time, surface disturbance may initiate anomalous heat flow. In case of linear disturbance over peat plateaus, such as seismic lines, this flow is narrowly directed along the borders of the seismic line accelerating permafrost thaw. The objectives of this study was to assess the influence of the year round unfrozen water body (i.e. channel fen and flat bogs) on frozen peat plateau disturbed by seismic line, which was cut in winter 1985. The findings suggest that the presence of such heat source, such as channel fen and flat bog, in close proximity of the disturbed permafrost terrain has a profound effect on temperature distribution along the linear disturbance, causing accelerated thaw from the top as well as from the bottom of permafrost. The heat flux is coupled with mass flux and can be observed all year round, being on its peak during summer months.
The study was conducted in the Scotty Creek basin (at 61.31N and 121.30W), approximately 60 km SE from Fort Simpson, North West Territories. A number of geophysical surveys were performed to delineate permafrost, peat and mineral soil borders. Temperature and water level observations were carried out throughout two years period in order to understand the influence of heat storage on the temperature distribution along the seismic line and consecutive permafrost degradation.