What relationship between accumulation and ablation is necessary for a glacier to form?
In cold regions (either towards the poles or at high altitudes), more snow falls (accumulates) than melts (ablates) in the summer season. If the snowpack starts to remain over the summer months, it will gradually build up into a glacier over a period of years.
What happens when accumulation equals ablation?
The part of the glacier that has more ablation than accumulation is the ablation zone. Where ablation is equal to accumulation is the Equilibrium line altitude. The snowline at the end of the summer season is often used to demarcate the equilibrium line on satellite images of glaciers.
What is accumulation and ablation?
The accumulation area is situated at the upper part of a glacier where the precipitation is mainly accumulated, while the ablation area is placed in the lower part where the precipitation is expended (Figure 1). Usually, the upper part of a mountain glacier is actually a firn basin.
When ablation is greater than accumulation in a glacier What happens to it?
If ablation outpaces accumulation, mass balance is negative and a glacier shrinks. If the two processes result in no net gain or loss of snow and ice, the mass balance is zero and the glacier is in equilibriumequilibrium: a balanced state with no net gain or loss..
What does accumulation mean in geography?
The accumulation area of a glacier is the part always covered by snow, where snow and ice are added to the glacier system. The addition of snow and ice is called ‘Accumulation’ and can occur through direct snow fall, the accumulation of wind blown snow, and through firnification.
What happens in the ablation area?
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.
What is the boundary between the zone of ablation and zone of accumulation called?
the equilibrium line
The boundary between the accumulation and ablation zones is called the equilibrium line.
What happens in the accumulation zones?
On a glacier, the accumulation zone is the area above the firn line, where snowfall accumulates and exceeds the losses from ablation, (melting, evaporation, and sublimation). Part of the glacier where snow builds up and turns to ice moves outward from there.
What is the mean of accumulation?
Definition of accumulation 1 : something that has accumulated or has been accumulated an impressive accumulation of knowledge. 2 : the action or process of accumulating something : the state of being or having accumulated the steady accumulation of snow.
What processes happen in the zone of ablation?
What three processes contribute to ablation?
(1) combined processes (such as sublimation, fusion or melting, evaporation) which remove snow or ice from the surface of a glacier or from a snow-field; also used to express the quantity lost by these processes (2) reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches.