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GEOREF RECORD

The first 20 years (1978-1979 to 1998-1999) of ice-wedge growth at the Illisarvik experimental drained lake site, western Arctic coast, Canada

J. Ross Mackay and C. R. Burn
The first 20 years (1978-1979 to 1998-1999) of ice-wedge growth at the Illisarvik experimental drained lake site, western Arctic coast, Canada
Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre (January 2002) 39 (1): 95-111

Abstract

In August 1978, a large tundra lake was drained to study the aggradation of permafrost into newly exposed lake-bottom sediments. Ice-wedge growth, which started in the first winter following drainage, had ceased in most of the lake bottom within about twelve years. The gradual cessation of thermal contraction cracking can be attributed to rapid vegetation growth, snow entrapment, an increase in winter ground temperatures, and a decrease in the linear coefficient of thermal contraction associated with freeze-thaw consolidation of the initially saturated lake-bottom sediments. The tilt and separation of markers in the active layer revealed gradual convergence towards the troughs even after ice-wedge growth had ceased. For the first few years the ice-wedge growth rate was up to 3 cm/a as determined by excavation, drilling, separation of the bottoms of benchmarks installed into permafrost, and divergence of free-floating inductance coils placed on the sides of ice wedges well below the bottom of the active layer. The vertical extent of most ice wedges was probably about 2 m, as deduced from the depths of ice-wedge cracks and the geometries of the wedge tops. Many thermal contraction cracks propagated upward to the ground surface from the tops of the ice wedges rather than downward from the ground surface. Small, upward facing, horizontal steps and vertical slickensided surfaces in permafrost on both sides of an excavated ice wedge near its top indicated that the adjacent permafrost had moved upward, relative to the wedge, from thermal expansion during the warming period.


ISSN: 0008-4077
EISSN: 1480-3313
Coden: CJESAP
Serial Title: Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre
Serial Volume: 39
Serial Issue: 1
Title: The first 20 years (1978-1979 to 1998-1999) of ice-wedge growth at the Illisarvik experimental drained lake site, western Arctic coast, Canada
Affiliation: University of British Columbia, Department of Geography, Vancouver, BC, Canada
Pages: 95-111
Published: 200201
Text Language: English
Summary Language: French
Publisher: National Research Council of Canada, Ottawa, ON, Canada
References: 33
Accession Number: 2002-029849
Categories: Geomorphology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: Polar Cont. Shelf Proj., Contrib. No. 002700
Illustration Description: illus. incl. sketch map
N69°15'00" - N69°30'00", W135°00'00" - W134°45'00"
Secondary Affiliation: Carleton University, CAN, Canada
Country of Publication: Canada
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute.
Update Code: 200211
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