| Summary: | This thesis investigates the nature and distribution of ground ice occurrences on the central Fosheim Peninsula, Ellesmere Island, and assesses the potential for thermokarst in light of possible climatic warming. Field observations conducted in 1990 and 1991 involved geomorphological and cryostratigraphic examinations of twenty-eight ground ice sections exposed in retrogressive thaw slumps and ground probing radar surveys of two of the thaw slumps. Samples were taken of ground ice and sediments exposed in thaw slump headwalls for laboratory analysis. Samples were analyzed for moisture content, grain size distribution, and Atterberg limits. Gravimetric ice contents were calculated and an average ice content profile was constructed for the study area. Ground ice was found to be an important component of permafrost on the Fosheim Peninsula and was widely observed in Holocene marine sediments. The ice occurred in two stratigraphic settings at depths of one to five meters in silt and clay, and at ten meters or deeper beneath massive clay. Ice contents were generally found to increase rapidly with depth down to three meters, below which ice content was stabilized. Ground probing radar was found to be a useful tool for permafrost research, given its ability to discriminate between ice and soil, as well as between frozen and unfrozen water.
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