Topic 4: Glacial systems

Question 1

What is a glacier? Some important characteristics

Answer 1

• body of ice, minimum of 30 meters thick
• flows under its own weight, doesn’t need gravity to move
• acts as a freshwater bank, and is a part of the water system
• A large part of Earths albedo system - cools down the earth

Question 2

What are 3 sections of a glacier?

Answer 2

• zone of ablation
• equilibrium line
• zone of accumulation

Question 3

What is the zone of ablation? zone of accumulation?

Answer 3

Ablation: Where the glacier is loosing ice, melting (edges/front)

Accumulation: where snow falls, accumulates, and crystalizes into ice (center)

Question 4

What are the three ways to classify glaciers based on temperature?

Answer 4

Cold based: Ice is frozen to the bed, basal temperature below pressure melting point

warm based: basal temperatures at pressure melting point

polythermal: variable bed conditions result in both warm and cold based components

Question 5

What are the three ways to classify glaciers based on topography?

Answer 5

Plateau ice caps: cover plateaus and feed valley glaciers

ice sheets: Not constrained by topography, motion driven by mass balance

valley glaciers: Strongly controlled by topography