ablation Loss of snow and ice from a glacier by sublimation , melting, and evaporation. Ablation also results from the calving of icebergs, and avalanches . In temperate and sub-polar regions melting is the most important process in ablation, whereas in the Antarctic the most important ablation process is calving. The rate of loss varies with the meteorological factors of air temperature, relative humidity, wind speed, and insolation , together with aspect and the nature of the surface. In snowfields, ablation ...