Warm/cold glaciers

Question 1

Temperate glacier (alpine or valley)

Answer 1

Melt in summer, the meltwater acts as lubricant and reduces friction. Erosion, deposition and transportation occur at an increased rate as the glacier is moving more. (AKA Warm based glaciers)

Mainly move by basil sliding as the base melts (because base temp is above pressure melting point)

Question 2

Cold based glaciers - Polar (ice sheets/Caps)

Answer 2

These glaciers occur when the temperature is permanently below 0 degrees and therefore no melting occurs. They are frozen to their beds and movements is internal and slow . Don’t move by basil sliding instead they move by internal deformation. Move around 1-2 cm a day.

Question 3

Pressure melting point

Answer 3

Melting point of ice is 0 degrees at the surface of the ice. This can vary. The base of the glacier may be warmer due to the pressure exerted from the mass of the glacier. This means the base of the glacier can melt even though the surrounding temps are below 0 degrees. (Relevant to temperate glaciers)

Question 4

Relegation

Answer 4

Due to pressure and increased temps , ice melts and moves over and around obstacles. Then it refreezez when pressure is reduced on the downside of the obstacle

Question 5

Bed deformation

Answer 5

This movement is accomplished by the deformation of soft sediment or weak rock beneath a glacier

Question 6

Internal deformation (cold based glaciers)

Answer 6

The ice crystals within the glacier orientate themselves in the direction of ice movement. This allows the ice crystals to slide past one another. 2 types of internal deformation (intergranular + Laminar)

Question 7

Intergranular internal deformation (cold based glaciers)

Answer 7

Individual grains of ice slide past one another

Question 8

Laminar internal deformation (Cold-based glaciers)

Answer 8

Layers of ice crystals slide over each other