1. Changing Earth’s Surface
Glaciers
Changing Earth’s Surface

2. 5 Agents of Erosion
Gravity
Running Water
Glaciers
Waves
Wind

3. Glaciers Glacier – any large mass of ice that moves slowly over land.
Two Types
Continental
Valley

4. Continental Glaciers
A glacier that covers much of a continent or large island.

6. Ice Age
Continental glaciers have covered larger parts of Earth’s surface.

8. Valley Glaciers
A long, narrow glacier that forms when snow and ice build up high in a mountain valley.

10. Valley Glaciers
Once the depth of the snow and ice reaches more than meters, gravity begins to pull the glacier downhill.

11. Valley Glaciers
Rate – a few centimeters to a few meters per day.

12. Glaciers Shape the Land
Erosion
Deposition

13. Glacial Erosion
Plucking – the process by which a glacier picks up rocks as it flows over the land.

14. Glacial Deposition
When a glacier melts, it deposits the sediment it eroded from the land, creating various landforms.

15. Till
The mixture of sediment that a glacier deposits directly on the surface.
Clay, silt, sand, gravel, and boulders

16. Deposition Landforms Moraine Terminal Moraine
The till deposited at the edges of a glacier forms a ridge.
Terminal Moraine
The ridge of till at the farthest point reached by a glacier
Long Island NY is a terminal moraine from the last ice age.

18. Deposition Landforms Kettle
A small depression that forms when a chunk of ice is left in glacial till.
Kettles often fill with water. Many found in Minnesota