1. GEOLOGY CMU Bill Palmer
Lecture 15
Glaciers

2. GEOLOGY
Glaciers-are slow moving rivers or sheets of ice that survive the summer melt. Found at high elevations in mountains or northern latitudes.

3. GEOLOGY Mountain Glaciers-exist in mountains and high elevations.
Flow from high to low-may be very steep
Associated with cirques (bowl shaped depressions on mountain sides)

4. GEOLOGY
Mountain Glaciers are rivers of ice.

5. GEOLOGY
Continental Glaciers-Cover large areas-Antarctica and Greenland. (over land not water so artic doesn’t qualify)

6. GEOLOGY
Continental Glacier

7. GEOLOGY
When glaciers move they create crevasses-large cracks in the ice. Crevasses may be 100s of meters long and 10s of meters deep.
When glaciers melt it is glacial retreat.
When pieces of a glacier break off and fall into the ocean it creates an iceberg.
Sea ice is just floating ice on ocean in Artic and Antarctic.

8. GEOLOGY
Crevasse
Iceberg
Sea Ice

9. GEOLOGY
Cirque-A owl shaped depression left on a mountaintop by a glacier
Horn-a pointed mountain peak with three cirques at base
U-shaped valley-scoured out by a glacier
Hanging Valley-when glacier cuts valley below a side valley

10. GEOLOGY
Cirque
Matterhorn
Hanging Valley
U-shaped valley

11. GEOLOGY Stuff Glaciers leave behind Fjords-steep cliffs into oceans
Glacial Till-Ground up rock and debris transported by glacier and left behind when glacier melts
Erratics-boulders left behind when a glacier melts

12. GEOLOGY
Fjords
Erratic

13. GEOLOGY Stuff Glaciers leave behind-Moraines
Terminal Moraine-at the end of the glacier
Lateral Moraine-on the sides of the glacier
Drumlins-long hills of glacial till formed by glaciers
Kettle-hole formed by glacier

14. GEOLOGY
Terminal Moraine
Lateral Moraine

15. GEOLOGY
Drumlin
Kettle

16. GEOLOGY Missouri was covered by a glacier about 10,000 years ago
Missouri River is southern limit of glacier
Formed by meltwater from glacier

17. GEOLOGY-Wrap-ups 1. What is a glacier?
2. What are four mountain structures associated with glaciers?
3. What is an erratic?
4. What is a drumlin?
5. How was the Missouri River formed?