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

被引:108
作者
Mackay, JR
Burn, CR
机构
[1] Carleton Univ, Dept Geog & Environm Studies, Ottawa, ON K1S 5B6, Canada
[2] Univ British Columbia, Dept Geog, Vancouver, BC V6T 1Z2, Canada
关键词
D O I
10.1139/E01-048
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
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.
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页码:95 / 111
页数:17
相关论文
共 34 条
[1]  
[Anonymous], PROBLEMS CRYOLITHOLO
[2]  
BERG T. E., 1966, Antarctic Res. Ser. (Am. geophys. Union)., V8, P61
[3]  
BLACK RF, 1974, PUBLICATIONS GEOMORP, P247
[4]  
BURGESS M, 1982, P 4 CAN PERM C CALG, P3
[5]   EVIDENCE FOR RECENT TEMPERATURE-INDUCED WATER MIGRATION INTO PERMAFROST FROM THE TRITIUM CONTENT OF GROUND ICE NEAR MAYO, YUKON-TERRITORY, CANADA [J].
BURN, CR ;
MICHEL, FA .
CANADIAN JOURNAL OF EARTH SCIENCES, 1988, 25 (06) :909-915
[6]  
BURN CR, 2000, ILLISARVIK BIBLIO
[7]  
CHAMBERLAIN EJ, 1978, P 3 INT C PERM EDM A, V1, P622
[8]  
GRECHISHCHEV SE, 1980, 3RD INT C PERM EDM 1, P259
[9]  
GRECHISHCHEV SE, 1976, BASIS METHOD PREDICT
[10]  
HOBBS PV, 1974, ICE PHYSICS