ablation

The loss of snow and ice from a glacier by melting and evaporation. It is the opposite of accumulation.

Ablation is most significant near the snout (foot or end) of a glacier, since temperatures tend to be higher at lower altitudes. The rate of ablation also varies according to the time of year, being greatest during the summer. If total ablation exceeds total accumulation for a particular glacier, then the glacier will retreat.