3.1.4.3 Warm and Cold Based Glaciers Flashcards
2 ways of classifying glaciers
By thermal regime/ characteristics By morphology (size, shape and location)
2 types of glaciers (thermal regime)
Temperate (warm-based)
Polar (cold-based)
Where do temperate glaciers occur
E.g.
Areas with milder summers
Where relief is steeper
E.g the alps
How do temperate glaciers move
By basal flow
Surges
Creep
Extending/compressing flow
What do temperate glaciers release huge amounts of
Meltwater which acts as lubricant
What’s a temperate glacier more likely to do
Erode
Transport
Deposit material
Where do polar glaciers occur
E.g
In very cold areas where the temperature is below 0*c and is no melting
E.g Greenland, Antarctica
Which type of glaciers move slower
Why
Polar
Frozen to their beds
What’s the main way polar glaciers move
Internal flow
What occurs much less in polar glaciers
Erosion
Transportation
Deposition
What are the 5 main types of glaciers (morphology)
Niche glaciers Corrie/cirque glaciers Valley glaciers Piedmont glaciers Ice caps and ice sheets
What’s the smallest size glacier
Niche glaciers
What’s the larger size glacier
Ice caps and ice sheets
What are niche glaciers
Very small
Occupy hollows
What are Corrie glaciers
Glaciers occupying armchair shaped hollows in mountains
What do Corrie glaciers often do to feed valley glaciers
Overspill from their hollows
Where do valley glaciers flow from
What do they follow
Flow from highland areas where ice accumulates
Usually follow former river courses bounded by steep sides
When are piedmont glaciers formed
When valley glaciers extend onto lowland areas, spread out and merge
What do ice sheets not bury
High mountains called nunataks
What point of a glacier is warmer
Lowest depth
What causes melting point to reduce
Higher pressure
What does ice normally have as it moved downhill
Great rigidity and strength
How does ice behave under pressure moving downhill
As a plastic (mouldable) body
When ice is put under sudden compression or tension what does it do
Shear apart
What part of a glacier is the fastest
And what does this cause
The surface
Causing ice to break and crack producing crevasses
What parts moves slower
Base and sides
What happens to PMP as pressure increases
Decrease
