1. GLACIERS
CGF3M Nov. 5, 2013

2. What is a Glacier?
A Glacier is a mass of ice with the following characteristics:
It extends at least 1/10th of a sq. km
It originates on land
it moves, or shows evidence of having moved.
About 10% of the Earth’s surface is covered by ice.

3. years ago…
During the last ice age, 30% of the Earth’s surface was covered by ice.

4. 3 Types of Glaciers Continental Glaciers- (Ice Sheets)
these are the largest on Earth.
Found only in Antarctica and Greenland
contain 95% of the Earth’s ice
Ice caps are smaller than Continental Glaciers
The Antarctic Glacier covers an area larger than the US and Mexico combined!

5. 3 Types of Glaciers 2. Ice Shelves
Are attached to land but float on water
Can extend hundreds of kms from land
Up to 1 km thick

6. 3 Types of Glaciers 3. Alpine Glaciers
Occur at high elevations in mountainous regions
smallest type of glacier
There are several in Alberta and BC. Here is a picture of Victoria Glacier in Lake Louise, AB.

7. What Role do Glaciers Play in the Water Cycle?
Store 75% of the world’s fresh water
Release some water as they melt, transporting it to watersheds

8. How do Glaciers Form?
Glaciers are formed from snow, over hundreds of years. Firn- transition between snow and ice Accumulation- rate at which the glacier is growing Ablation- rate at which the glacier is shrinking

9. Surging Glacier in Alaska

10. Terminology
When a glacier flows rapidly, giant cracks called crevasses form.
As a glacier moves, it collects debris and carries it along or deposits it at the base of the glacier. This is called a moraine.

11. Calving- when large pieces of ice break off an ice shelf and create icebergs
The largest recorded iceberg (it broke off the Ross Ice Shelf in Antarctica) was sq. kms- the size of Jamaica!
See the largest witnessed calving in action in Greenland…

12. Antarctica
Read the article and explain what is happening to the Antarctic Ice Shelf