Glacial ice

Question 1

Lower zone

Answer 1

• Zone of plastic flow
• Steady pressure
• Meltwater resulting from pressure + friction with bedrock = more rapid flow (plastic)
• Depth in glacier, meltwater point of ice is raised slightly = increased pressure
• Moulds like plastic
• Doesn’t flow in a uniform way
• Different speeds

Question 2

Upper zone

Answer 2

• Rigid zone
• Great rigidity and strength
• Brittle, which breaks apart to form crevasses
• Moves in a uniform way at the same speed.