Thus
a glacier
has two zones: the area of accumulation where snow is retained, and the ablation area where more ice melts than accumulates.
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.
What is the zone of equilibrium?
The line or zone on a glacier's surface where a year's ablation balances a year's accumulation (cf. Firn line). It is determined at the end of the ablation season, and commonly occurs at
the boundary between superimposed ice
(q.v.) and glacier ice.
What are the 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.
Where is the zone of ablation?
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 equilibrium line of a glacier?
boundary
between the accumulation area and ablation area where the mass balance is zero
. glaciers.
Where can one find a glacier's equilibrium line?
The equilibrium line is
at the boundary of the accumulation area and the ablation area
, however, the elevation varies from year to year. The ice flows downhill from the accumulation zone towards the ablation zonewhere higher temperatures intensify the melting.
What happens if accumulation exceeds ablation?
The lower area of a glacier where the rate of ablation is higher than the rate of accumulation. Occurs over a time period when
accumulation averaged across the whole glacier exceeds ablation averaged across the whole glacier
. The glacier becomes larger and extends further. … The loss of ice or snow from a glacier.
What does a Cirque look like?
Cirques are
bowl-shaped, amphitheater-like depressions
that glaciers carve into mountains and valley sidewalls at high elevations. Often, the glaciers flow up and over the lip of the cirque as gravity drives them downslope.
What is snow 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.
What is the edge of a glacier called?
Terminus
. The lower-most margin, end, or extremity of a glacier. Also called Toe, End or Snout.
What are the three main parts of a glacier?
Head
: The uphill, top end of a glacier. Terminus: The downhill, bottom end of a glacier. Snowline: The area between the summer melting and accumulation area where the snow lasts from season to season. Brittle Zone: Crevasses are common in this zone.
What is the area where a glacier melts called?
The ablation zone
is the region where there is a net loss in glacier mass. … After a glacier melts, it often leaves behind a bowl- or amphitheater-shaped depression that ranges in size from large basins like the Great Lakes to smaller mountain depressions known as cirques.
What is the difference between a glacier's 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 causes glacier ablation?
As ice flows downhill, it either reaches warmer climates, or it reaches the ocean
. This causes various processes of melt, or ablation, to occur. … 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 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
.
