Showing papers on "Accumulation zone published in 1978"

The engineering significance of glacier ice-thrusting

Abstract: Field evidence in Saskatchewan indicates that glaciotectonic processes result in a significant change in the shear strength properties of the sediments and the boundary conditions for the groundwater regime. Glacier ice-thrusting resulting in the deformation and shearing of bedrock and glacial sediments appears to be widespread throughout southern Saskatchewan and probably elsewhere where continental glaciers overran clay shale or weakly cemented bedrock. Theoretical considerations indicate that wherever a glacier is forced into compressive flow by physical features that tend to decrease flow downstream, shearing thrust planes develop in the ice causing brecciation, slickensides, overthrust faulting, and drag folding of sediments that have been carried up into the ice. The conditions required to produce this phenomenon include upslope movement of the glacier over a concave surface and net ablation in the glacier regime. Three examples of the engineering implications of this process are included where mass...

Study of the Mass Balance of Small Glaciers in Khumbu Himal during the Summer Monsoon Season

Abstract: Glaciological observations were made for the study of the glacier mass balance in the Nepal Himalayas, which is characterized by the simultaneous occurrence of considerable accumulation and ablation during the summer monsoon season. The upward change of the glacier surface level and the considerable amount of deposited snow due to the summer snowfall were observed at the end of summer over the whole area of the glaciers by means of stake measurements and stratigraphic observations respectively. On the other hand, the mass balance from July to September is calculated in consideration of the ice amount to be superimposed on the glacier ice of sub-zero temperature. The growth of the superimposed ice contributed to the positive mass balance in the upper-middle part of the glacier, while the mass balance during the same period was negative in the lower part. The total of the sum mer balance for the whole area of each observed glacier is concluded to have been positive. Such a positive summer balance is attributed mainly to the accumulation in late summer.

The Glacio-Climatological Study on the Kai-gata Glacieret, Mt. Chokai (2)

Abstract: A ground based photogrametric survey and a triangular survey were progressed during the latter half of the ablation season of 1975 in succession with two simplified surveys in Octobers 1973 and 1974 for the shape and size measurements of the Kai-gata Glacieret, Mt. Chokai which is reported in the previous paper (Tsuchiya, 1977). Similitaneously the measurements of the movement of this glacier (a small niche type glacier) are carried out.The Kai-gata Glacieret became to its minimum size in 1972, then it became to larger size with perennial snow but mostly glacier ice in 1973, and it became to the maximum size and contained two year ice in 1974 during recent several decades. The distance of movement of this glacier during the latter half of the ablation season in 1974 was of 0.5-1 m but within the instrumental errors in measurement. In the case of 1975, it became to mostly two years ice mass and moved about 20m on the stage of decreasing of its size and thickness.The slope at the front of the glacier was 48°, 78° and 90° or more in 1973, 1974 and 1975 respectively, and a part of the ice wall appearently advanced during the period of August-October in 1975, namely the extent of the movement was larger than the ablation.