SNOW STUDIES IN ANTARCTICA.
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
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The seasonal distribution of snow at the South Pole and its relationship to stratigraphy was investigated in pits dug beside a number of 4 year old accumulation stakes. Results show that conventional stratigraphic methods yield thoroughly reliable values of accumulation rates. Even hiatuses in accumulation can be idenfified from the intensity of sublimation of layers of depth hoar. Such hiatuses can be attributed generally to the prolonged absence of accumulation rather than to widespread scouring of pre-existing layers of snow. The bulk of the years accumulation is deposited as dunes during winter. Most dunes are subsequently transformed into linear sastrugi so that by winters end the amplitude of the surface relief frequently exceeds the thickness of snow accumulated annually. During the summer, however, these dunes and sastrugi are gradually worn down by a process of sublimation - deflation. This leveling of the surface relief is believed to be the significant factor in the formation of the remarkably uniform stratigraphy observed in pits at the South Pole. An examination of bullet crystals in precipitation at the South Pole indicates that combinations of bullets originate as primary growth structures and that individual bullets are formed as a result of the disintegration of these primary growth forms rather than by independent crystallization of pyramidally terminated columns. Three years measurements of snow accumulation on undulating surfaces around Byrd Station, Antarctica, indicate that the undulations are tending to be filled in. These results are discussed in the light of current knowledge of the origin and migration of such features. Author
- Snow, Ice and Permafrost