EQ2 Flashcards
Formation of glacial ice
Snow falls, is compressed into neve, transforms into glacial ice
What is neve?
crystalline/granular snow which has not yet been compressed into ice
How long may it take for snow to turn to ice in polar vs temperate areas
Can be 100 years in temperate and 4000 in Antarctica
what is glacier mass balance?
gains and losses of the ice store
What is accumulation?
Gains in the ice store. Caused by direct precipitation, avalanches
What is ablation?
Losses from the ice store. Caused by processes like melting, calving, evaporation
What is equilibrium point?
losses from ablation are balanced by gains from accumulation
What is glacial budget?
the difference between accumulation and ablation.
What happens if a glacier has a positive mass balance?
Accumulation exceeds ablation, so the glacier advances.
what are 3 factors affecting rate of movement?
altitude, slope, size
What is internal deformation?
Deformation of layers of ice or individual ice crystals
caused by the pressure from the weight of the ice. This causes some layers to move faster than others, so different parts of the glacier can be further advanced
What is basal slip?
meltwater beneath a glacier acts as a lubricant reducing friction. Can account for up to 75% of movement in warm-based glaciers
What is a positive feedback loop?
A process occurs, which leads to another process occurring, heightening the first process.
What are the types of glacial processes that alter landscapes?
Erosional, entrainment, transport and depositional
3 examples of erosional processes
Plucking, abrasion, meltwater erosion
