CGRG Bibliography of Canadian Geomorphology
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Author : Burn, C.R.
Date : 1998
Title : Field investigations of permafrost and climatic change in northwest North America.
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) : 107-120.
Abstract
Yukon Territory, adjacent portions of Northwest Territories, and Alaska contain a continental range of permafrost conditions. The response of permafrost to climatic change is recorded in the cryostratigraphy of late Pleistocene and Holocene sediments, with an early Holocene thaw unconformity being a widespread and prominent feature. More recently, temperature profiles from deep boreholes show an inflection associated with near-surface warming of 2° to 4°C since the Little Ice Age. Simultaneously, the southern limit of permafrost has moved northwards. In order to understand the present climate:ground temperature system, an analytical solution has been verified to relate the annual mean ground surface temperature to the annual mean permafrost surface temperature under equilibrium conditions. Ground surface temperatures have been obtained from air temperatures using n-factors. The solution assumes that heat transfer in the active layer is only by conduction. The relations show that the impact on permafrost temperatures of changes in snow cover and soil moisture conditions may surpass the effect of changes in air temperature per se. Observations from the sporadic permafrost zone indicate the persistence of permafrost despite recent warming. This is due to minimal snow cover on residual peat landforms, and to latent heat in ice-rich ground. The persistence further complicates interpretation of the response of permafrost to climate change.
Bibliography of Canadian Geomorphology