What does ablation of a glacier mean?
(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.
What happens in a zone of ablation in a glacier?
Ablation zone—the part of the glacier where summer melting exceeds winter accumulation. This includes not only the total melting of the snow cover of the last winter but also a layer of glacier ice. A deficit of mass appears in that area. The zone lies at lower altitudes of the glacier surface.
Where is the ablation zone?
In large parts of Antarctica, melting underneath the base of floating ice shelves and calving from the margin of the glaciers dominate over surface melt. The lower part of the glacier generally loses more mass from ablation than it receives from accumulation. This part of the glacier is the ablation zone.
What is the zone of accumulation in a glacier?
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). The annual equilibrium line separates the accumulation and ablation zone annually.
What is ablation?
Ablation is a procedure to treat atrial fibrillation. It uses small burns or freezes to cause some scarring on the inside of the heart to help break up the electrical signals that cause irregular heartbeats. This can help the heart maintain a normal heart rhythm. The heart has 4 chambers.
What is a zone of ablation in geology?
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 processes happen in the zone of ablation quizlet?
What processes happen in the zone of ablation? Ice gradually is lost, due to a combination of melting, sublimation, and calving.
Where is the brittle zone of the glacier?
upper 150 feetThe zone of brittle flow, the upper 150 feet of glacial ice, lacks this pressure and reacts in-elastically to the bedrock features, forming elongated cracks called crevasses which fluctuate with the glacier's flow.
What is the terminal face of a glacier?
The terminus is the end of a glacier, usually the lowest end, and is also often called a glacier toe or snout. Early glacier explorers pose in front of the terminus of Bradfield Glacier, which spans the border between Alaska and Canada.
What is zone of accumulation and zone of ablation?
The zone where there is net accumulation (where there is more mass gained than lost) is the accumulation zone. 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.
What are the three zones of a glacier?
During movement there are three parts of the glacier: The zone of basal sliding; the zone of plastic flow; and the rigid zone. The rigid zone is brittle and sometimes is broken into crevasses. Ice sheets move with these three zones but often spread laterally rather than flow downslope.
What are the two zones of a glacier?
This is called the accumulation zone, and is typically covered in snow year-round. The glacier is in constant motion as the ice in the accumulation zone flows down to lower altitudes, into what is called the ablation zone. The ablation zone is the lower part of the glacier where more snow is lost than accumulates.