Generelt Flashcards
What is needed for the formation of glaciers?
Low temperature
Sufficient snow fall
Favourable relief
What is important for the Low temperatures needed for the formation of glaciers?
The summer temp. - all snow from winter must not melt
Increase of distance to the poles - increased height in which snow can fall
What is important in relation to Sufficient snow fall in the formation of glaciers
If there is High evaporation+low precipitation there can be no ice sheets.
West coast are best (high precipitation).
Seasonal distribution of precipitation (snow is needed, not rain)
What is important in relation to the Favourable relief in the formation of glaciers?
There needs to be some sort of depression for the snow to accumulate.
(Also ex. Lee-side positions in mountains)
What happens with the compaction of snow?
The density changes (new snow lightest, glacier ice densest)
What is firn?
Old snow that has survived the summer.
Important for the formation of glaciers!
How is glacier ice defined? (?)
It is ice that deforms and moves under its own weight
How does the ice in the glacier move, and where is it thickest?
It moves from the middle, downwards and out.
It is thickest in the middle where the accumulation is
What is stagnant ice?
Ice that is no longer moving
What is 2 glacier types?
Continental ice sheets - mountains needed.
Instantaneous glacierization (several glaciers (ice domes) can affect each other)
What does glaciers globally affect?
Sea level changes
How does glaciers affect the globe?
Eustatic Sea level fluctuations - change in water volume (global Sea level changes?)
Isostasy
What is LGM?
Last glacial maximum (globally)
What is permafrost and the active layer?
Frozen ground (2+ years)
The active layer undergoes freezing/thawing cycles
