One of five glacier zones used to categorize areas on glaciers in terms of ice temperature and melting. The ablation zone is the area below the equilibrium line below which there is a net loss of ice over the year. The superimposed ice zone exists above this line.

The area of a glacier where mass is lost through melting or evaporation at a greater rate than snow and ice accumulate.

On a glacier, the zone of ablation occurs where summer loss of snow through melting, evaporation, and sublimation exceeds winter accumulation on the surface. A zone of ablation, because it is below the firn line, can be identified in the summer by an expanse of bare ice or firn. The annual equilibrium line separates the accumulation and ablation zone annually.

The area of tissue removed during refractive surgery; needs to approximate the pupil size to avoid post-op glare and halos

is the area of tissue that is removed during laser surgery.