Ablation zone or ablation area refers to the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass due to melting, sublimation, evaporation, ice calving, aeolian processes like blowing snow, avalanche, and any other ablation.
The term "ablation zone" describes the area on glaciers and ice sheets where ice is lost through various processes like melting, sublimation, wind-driven removal, and calving.