1. Continental and Alpine
Glaciers
Continental and Alpine

2. All glaciers form . . .
All glaciers form when the annual snowfall in an area exceeds the annual snow melt
Over many years, the snow accumulates, compacts and turns to ice

3. Glaciers on the move Glaciers “advance” as they get bigger.
Advancing glaciers means that more snow and ice are building up than melting
Glaciers “retreat” as they get smaller.
Retreating glaciers are a sign that snow melt is greater than snow fall.

4. Glaciers and water
Approximately 10% of all land area is currently covered by glaciers
Remember: Only 30% of the Earth is land, so 10% of that is only 3% of the earth’s surface
Approximately 70% of all fresh water is held in glaciers

5. Continental glaciers cover vast land areas
Today they are only found near the poles in the Arctic and Antarctic

6. Former Ice sheets
The continental glaciers that covered this part of Ohio started in Canada
The dark line marks the terminal moraines – piles of till that mark the farthest point the glaciers reached

7. As glaciers move, they weather rock below them
Frost wedging happens below the ice as water seeps into cracks in the rock and refreezes.
When it refreezes, chunks of ice are broken off and stuck to the bottom of the glacier. This is known as plucking

8. Glaciers are agents of weathering, erosion, AND deposition
Glaciers transport plucked rocks long distances and deposit them as erratics.
Plucked rocks abrade the surface beneath the glacier

9. Till – deposited by moving ice
Glacial deposits
Till – deposited by moving ice
heterogeneous mixture; sizes are all mixed together
Moraines
Terminal moraines
Recessional moraines
Ground moraines
Stratified Drift - deposited by running water
Stratified drift is made of layers of different sized particles
Outwash plains
Drumlins
Eskers
Kames

10. New York has drumlins!
These long, low, teardrop shaped hills form under the moving glacier.
In western NY state, there is a region known as the Finger Lakes that contains hundreds of drumlin hills.
They have been observed forming under the ice in Antarctica

11. Glaciers can have tributaries too!
As smaller glaciers join a larger one, they create a complex system of valleys
At the bottom of the valley, the outwash plain is essentially the delta for the glacier where water runs out and drops its sediment.