Lesson 3: Glaciers

Question 1

Define warm based glaciers

Answer 1

-Occur in high altitude areas outside the polar regions
-Temp. of ice is closer to zero and mild summer temps. cause melting

Question 2

Example of warm based glacier

Answer 2

Alps

Question 3

Define cold based glaciers

Answer 3

-Occur in polar glacial environments
-Frozen onto the bedrock below and melting only occurs on the surface in the summer months

Question 4

Example of cold based glacier

Answer 4

Greenland
Antarctica

Question 5

Define glacier

Answer 5

Large bodies of ice which flow downhill under the influence of gravity

Question 6

How can glaciers be viewed as systems with inputs, stores, transfers and outputs?

Answer 6

Gain mass through the transformation of snow into ice and then flow downhill (in response to gravity) and eventually lose mass due to melting

Question 7

Define glacial budget

Answer 7

A glacier mass balance/annual budget is calculated using the total accumulation and ablation within a year

Question 8

What does a positive mass balance mean?

Answer 8

Accumulation greater than ablation - glacier increases in size

Question 9

What does a negative mass balance mean?

Answer 9

Ablation greater than accumulation - glaciers decreases in size

Question 10

Examples of accumulation processes

Answer 10

Avalanches
Rock debris
Meltwater
Aeolian deposition
Precipitation (mainly snow)

Question 11

Examples of ablation processes

Answer 11

Evaporation (sublimation)
Rock debris
Melting (water)
Break away of ice blocks and icebergs (calving)

Question 12

What is the equilibrium line?

Answer 12

When losses from ablation are balanced by gains from the accumulation in a glacier