Glacial budgets Flashcards
What are the inputs of a glacier?
2
Snow, water and ice (precipitation).
Avalanches.
What are the processes of a glacier?
5
Sunlight - melting. Freezing. Eroding. Movement. Gelifluction (seasonal freeze-thaw).
What is the storage of a glacier?
Represented by the glacier itself.
E.g. ice sheet, cap, shelf.
What are the outputs of a glacier?
4
Water vapour.
Sublimation (direct change from ice to water vapour).
Calving (formation of icebergs).
Ablation (water in the liquid form - melting).
What is the zone of accumulation and where is it located?
In the upper part of the glacier.
Greater than ablation leading to growth in ice mass and potential glacial advance down the valley.
Cold months.
What is the zone of ablation and where is it located?
In the lower part of the glacier.
Greater than accumulation, leading to loss in ice mass and potential glacial loss up the valley.
Warmer months.
What is the line of equilibrium?
It separates net loss from net gain.
It also represents the snow line on the glacier.
When is accumulation more prominent?
When is ablation more prominent?
In winter - snow accumulates.
In summer - snow melts.
What is the net balance?
It’s the difference between the total accumulation and the total ablation during one year.
What in the seasonal net balance like in temperate glaciers?
There is a negative balance in summer when ablation exceeds accumulation.
There is a positive balance in winter when accumulation exceeds ablation.
What happens if the positive and negative budgets cancel each other out?
The glacier appears to be stationary.
The snout of the glacier remains in the same position, although ice is still advancing down the valley from the zone of accumulation into the zone of ablation.
When does glacial advance occur?
Accumulation is greater than ablation leading to growth in ice mass and potential glacial advance down the valley.
When does glacial retreat occur?
Ablation is greater than accumulation leading to a loss of ice mass and the potential retreat of the glacier up valley.
