Geomorphic processes

Question 1

Cold based glaciers (polar)

Answer 1

-Glaciers -> ice frozen to the bedrock so has very little movement
- Found in Antarctica and Greenland
-Internal deformation -> ice crystals slide on top of each other
Temperature at the base is lower than pressure melting point so there’s not melting at the base resulting in no basal sliding. Surface temp too cold for water to exist at any point if the year

Question 2

Warm based glaciers (Temperate)

Answer 2

-Meltwater under the glacier allows for movement
-Found in the Alps and Alaska
-20-200m /year movement
-Basal sliding and internal deformation
-Pressure melting also causes meltwater
Temperature at the base is higher than the pressure melting point so melting occurs and allows for basal sliding. Water in summer - may end up at the base via fluvio-glacial system

Question 3

Internal deformation

Answer 3

-Ice crystals slide past each other
-Parallel lines form
-Greatest at the base of a glacier
-Crevasses form

Question 4

Basal sliding

Answer 4

-Pressure between ice and obstacle
-Pressure causes melting
-Water flows around and re-freezes

Question 5

Rate of movement

Answer 5

-gravity and gradient
-Meltwater amounts
-Ice temperatures
-Ice mass
-Nature of bedrock = permeability

Question 6

Steep gradient

Answer 6

-Fast moving
-Thinner
-Crevasses form
-Extensional flow
-Seracs form

Question 7

Shallow gradient

Answer 7

-Slow moving
-Thicker
-Compressional flow
-Crevasses close

Question 8

Movement of glaciers

Answer 8

-Rotational flow
-Permeability of rock -> Impermeable = faster movement
-Slow at edges, fast in the centre

Question 9

Pressure melting point temperature of warm based glaciers

Answer 9

4 degrees Celsius