Flashcards in Glacial Budget Deck (23)
What are glaciers?
Masses of ice which fill valleys and hollows.
Where do glaciers move?
Downhill under the force of gravity.
What 2 things does a glacier have?
Zone of accumulation.
Zone of ablation.
What is accumulation?
The input of snow and ice into the glacier.
What is ablation?
The output of water from a glacier as it melts.
What occurs in the upper part of the glacier?
More accumulation than ablation.
What zone is called the zone of the accumulation?
Upper part of the glacier.
What occurs in the lower part of the glacier?
More ablation than accumulation .
What zone is called the zone of the ablation?
Lower part of the glacier.
It may look like glaciers stay in the same place but what is happening?
Melting at the bottom end.
Growing at the top end.
What is the difference between the total accumulation and total ablation for one year?
The glacial budget.
What things depend on the glacial budget?
Amount of ice in glacier.
Whether its advancing or retreating.
What is a positive glacial budget?
When the accumulation exceeds the ablation .
Input exceeds output.
Describe positive features that glaciers should have?
Snout advances down the valley.
What is a snout of the glacier?
Bottom end of the glacier.
What is a negative glacial budget?
When ablation exceeds accumulation.
Output exceeds input.
Describe negative features that glaciers may have?
Snout retreats up the valley.
What happens if the amount of accumulation and ablation stays the same over a year?
Glaciers stays the same size.
Position of the snout doesn't change.
The glacial budget changed in both ___ ___ and ___ ____.
In the summer what occurs?
More ablation occurs then accumulation.
Because ice is melting due to warmth.
Negative glacial budget as glaciers retreat.
In the winter what occurs?
More accumulation occurs then ablation.
Because more snowfall and less melting.
Positive glacial budget as glaciers advance.
Since what year have glaciers had a negative glacial budget?