COLD: Ice Movement

Question 1

Movement of cold based glaciers? (5)

Answer 1

• Occur in polar latitudes
• Glacier remains well below freezing
• Ice remains frozen to the bedrock
• Very little ice movement
• Limited erosion

Question 2

Movement of warm based glaciers? (4)

Answer 2

• Most glaciers outside of Antarctica and Northern ice-caps
• Water present throughout ice mass, acts as a lubricant
• Movement of between 20-200 metres a year
• Increases capacity of glacier to erode bedrock

Question 3

What is pressure melting point? (3)

Answer 3

• Temperature at which ice is on the verge of melting
• At the surface of glacier is at 0 degrees
• Lower within glacier because ice is under pressure, so melts easily

Question 4

What is internal flow? (2)

Answer 4

• Movement within glacier ice, resulting from stresses by force of gravity
• Ice crystals orientate themselves in direction of glacier’s overall movement

Question 5

What is basal slippage? (5)

Answer 5

• Sliding effect of glacier
• Increasing pressure in lower ice causes pressure melting
• Meltwater permits slippage of ice over obstacles
• Refreezes in lower pressure conditions on down glacier side
• Creep may occur when little or no regelation slip