CGRG Bibliography of Canadian Geomorphology
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Author : Burn, C.
Date : 2010.
Title : Experimental rejuvenation of ice-wedge cracking at Illisarvik, western Arctic coast, Canada.
Publication : American Geophysical Union 2010 Fall Meeting, December 13-17, 2010. Moscone Convention Centre, San Francisco, California, U.S.A.
Issue :
Page(s) : C41C-02.
Abstract
The Illisarvik drained lake is a long-running field experiment to study terrain processes associated with aggradation of permafrost. The lake was drained in August 1978, and over the next ten winters thermal contraction cracks opened in the lake floor, and at one site an ice wedge 22 cm in width developed beneath a pronounced trough. Subsequently, growth of vegetation led to trapping of snow, higher winter ground temperatures, and cessation of cracking. Since 2000, the grass near the ice wedge has been cut in late summer and the winter snow cover has been reduced. As a result ground temperatures have declined, but cracking did not recur until 2005, and it has done so each winter since then. The active-layer depth at the site has decreased even though the vegetation has been trimmed due to the increased winter ground cooling. The thermal conditions for cracking at Illisarvik differ from the thresholds identified at sites with equilibrium permafrost, suggesting that in aggrading permafrost, critical conditions are not encountered only at the surface of permafrost. Deformation of the ground on either side of the wedge has been measured from the tilt and separation of benchmarks. At the ground surface the trough has increased in width by about 5 mm each year that cracking has occurred.
Bibliography of Canadian Geomorphology