CGRG Bibliography of Canadian Geomorphology
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Author : Coultish, T.L.; and Lewkowicz, A.G.
Date : 2002.
Title : Palsa development in Wolf Creek, Yukon Territory.
Publication : Special CGRG Session. Annual Meeting of the Canadian Association of Geographers – Ontario Division. University of Western Ontario, London, Ontario. October 25-26, 2002.
Issue :
Page(s) :
Abstract
Thirty-seven palsas were examined in Wolf Creek, Yukon Territory (60º30’N, 135º13’W, 1235 m a.s.l.). Cryostratigraphic analyses and aerial photographic interpretation were undertaken to investigate the origin and longevity of the palsas, and to assess their utility as climatic indicators. Aerial photographs from 1946 to 2001 showed that the palsas have been aggrading and degrading continually over the past 55 years, and are continuing to do so. Calculated rates of maximum aggradation and degradation were 4 and 6 palsas per decade respectively. The development of palsas in Wolf Creek appears to be influenced by non-climatic factors, which mask potential climatic effects. In particular, the construction and destruction of beaver dams along the stream can significantly alter water levels. High water can cause the degradation of palsas through thermal erosion, whereas new palsas can grow in areas where beaver ponds have drained. The climate at the palsa site is sufficiently cold (MAT of –4ºC from 2001-02) suggesting that the palsas would not be highly sensitive to climate at present. As a result of the additional influence of non-climatic factors, it is concluded that the palsas in Wolf Creek could be used as indicators only of very considerable future climate warming.
Bibliography of Canadian Geomorphology