What are glaciers?
Systems with inputs,stores and outputs
What are the inputs of a glacier?
- snow
- condensation of water and vapour from the air
- sublimation
- parts of the rock collected when the glaciers carves away at the landscape
What are the stores in glaciers?
The main store is ice
- meltwater
- debris
What are the outputs of a glacier?
Ice melting
Surface snow melting and evaporating
Snow blown away by strong winds
What is a glacial budget?
The balance between a glaciers outputs and inputs
What is the geographical term for inputs?
Accumulation
What’s the geographical term for outputs?
Ablation
What does the budget show?
Whether the volume of water in the system has increased or decreased,determining if the front of the glacier moves forward or retreats back
What happens if theirs more accumulation than ablation?
It has a positive regime + glacier moves forwards
Why do glacial budgets change throughout the year?
More ablation during the warmer times
Change in global temperature
How do glaciers form?
- when snow first settles it has a loose fluffy consistency
- the weight of the snow on top turns the snow denser and more granular
- air is squeezed out and the particles of ice are compressed together
- water melts and refreezes in the air spaces making ice more dense
Why is a warm based glacier warm?
The base is warmer than the melting point due to the heat from the friction caused by the glacier moving or geothermal heat
Key features of a warm based glacier?
- melted ice at bottom acts as a lubricant,making it easier for the glacier to move downhill
- lots of movement = lots of erosion
Key features of a cold based glacier?
Little melting
Little movement
Not much erosion
