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Proactive disclosure Print version | Taking the Chill Off: Climate Change in the Yukon and Northwest Territories Fire and Ice
Destruction of the vegetation by fire results in warming of the ground surface and can lead to an increase in the depth of summer thaw. Rapid thawing on slopes with ice-rich soils can result in a detachment or flow of the thawed surface layer. Such slope failures, known as active layer detachment slides, occurred after extensive areas of the Mackenzie Valley were burned during drier than normal summers of 1994 and 1995. Deeper and larger landslides on permafrost slopes may also increase if the number of forest fires increases as climate warms. Slope failures occurring along river banks will increase the sediment load and could affect fisheries and destroy spawning beds. Material from landslides may also form a dam, altering the hydrologic regime and temporarily affect transportation routes. Aylsworth, J.M. and Duk-Rodkin, A., 1997. Landslides and permafrost in the Mackenzie Valley; in Mackenzie Basin Impact Study (MBIS), Final Report, Environmental Adaptation Research Group, Environment Canada, p. 118-122. Dyke, L.D., Aylsworth, J.M., Burgess, M.M., Nixon, F.M. and Wright, F., 1997. Permafrost in the Mackenzie Basin, its influences on land-altering processes, and its relationship to climate change; in Mackenzie Basin Impact Study (MBIS), Final Report, Environmental Adaptation Research Group, Environment Canada, p. 112-117 Peatlands within the permafrost region are an important store of carbon. Thawing or burning of permafrost-affected peatlands may result in an alteration of the carbon cycle and the concentration of atmospheric greenhouse gases.
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