1. Glaciers and Long Island
How are
Glaciers and Long Island
related?

2. Glaciers Snowfall exceeds melting. High altitudes and polar regions.
Gravity moves mass downhill.
Firn = very dense snow layer.

5. Continental Glaciers Ice sheets that cover continents.
Kilometers thick.
Only 2 exist:
- Greenland and Antarctica

7. Valley Glaciers Begins in a cirque = bowl-shaped basin at mountaintop.
Crevasses = cracks in the glacier.

9. Erosion U-shaped Valleys Cirques, Aretes and Horns.
Hanging Valleys - from tributary

17. Erosion
Striations = parallel scratches on bedrock... from rocks on bottom of glacier
Polish = fine material rubs rock smooth.

18. Striations

19. Polish

20. Deposition Moraines - Unsorted pile of debris = till
Erratics = large isolated boulders.
Drumlins = long, low mounds of till with teardrop shape.
Outwash Plain (sorted) = sediments that are “washed out” in front of glacier.

22. Erratic

23. Central Park, NYC

24. Drumlin

25. Lakes
Kettle Formation:

26. Kettle Lakes

28. Glacial Lake
Forms when ice dams a stream.

31. Ice Age Glacier Limit