ON THE EFFECT OF STRONG DENSITY LAYERING ON METAMORPHISM OF SEASONAL SNOWCOVER

Recent studies by the authors in the Bridger Mountains near Bozeman, MT and at the South Pole have indicated the presence of peculiar metamorphism processes which can be significant under certain conditions. Normally temperature gradient metamorphism is the predominant process which produces the kinetic growth forms widely recognized in alpine snow. However, the authors have observed that in low density snow adjacent to a dense layer such as a thick melt-freeze curst or wind crust, the less dense snow appeared to lose mass and strength over the period of the winter prior to snow becoming isothermal in the spring. This was observed to happen even when the temperature gradient in this region was insignificant. Further observations have been made by the authors at the South Pole