1. Erosion & Deposition by Ice
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Erosion & Deposition by Ice
Show ice age video clip.
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2. 2 Types of Glaciers Continental Alpine
Cover large areas, like continents
Due to cold global climates
Alpine
Cover mountain tops and sides
Due to Orographic effect
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3. GLACIERS - VALLEY AND CONTINENTAL
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4. Glaciers Form when snow accumulation is greater than snow melting
Cause a build up of ice
Glacial movement is similar to streams (fastest in center)
Create "U" shaped valleys with nearly vertical walls and flat bottom
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7. Glaciers in North America over the past 2.0 x 106 years
Ice covered most of New York several times in the “recent” past
Most recently about 11,000 – 15,000 ybp.
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9. The last major glacial period
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10. Erosion by Glaciers Glaciers remove and carry sediments
Ice can be thousands of feet thick and thus very powerful.
Surface materials (like soil) are easily removed.
Sediments at the bottom of the ice act like sandpaper and scour the bedrock.
Continental and alpine glaciers have different erosional (and depositional) characteristics.
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14. Glaciers
Create features like striations
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16. Glaciers ….glacial polish
Where rocks within a glacier grind against bedrock
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17. Deposition by Glaciers
Mixed sized sediment drops vertically as glacier melts
Unsorted sedimentation
Sediments often scratched (striations)
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18. Glacial Deposition
This sediment is made of a variety of particle sizes
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19. Deposition by Glaciers
The large rocks left behind by glaciers are called glacial erratics
Large rocks not broken into small particles
Often different in composition than the bedrock upon which they sit
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20. NY Erratic
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21. Erratics in our area
  Based on this image, where did the erratics and other non -native rock in Harpursville come from?
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22. Deposition by Glaciers
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Deposition by Glaciers
Glacial till
Unsorted glacial sediment
Ranges from clay sized particles to boulders
stratified (sorted) sediment consists of glacial sediments carried by meltwater and deposited in an outwash plain
• view images to show these features
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23. Till- Sierra Nevadas
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24. A wide variety of landscape features are created by glaciation
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25. These features are most often associated with alpine glaciations:
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27. Drumlins- Oval shaped Moraine
Drumlin-Cranes Beach MA
Drumlins- Oval shaped Moraine
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29. Esker- Rivers on ice bore a hole in the ice and flow under the sheet
Esker- Rivers on ice bore a hole in the ice and flow under the sheet. Rocky material builds up and the stream bed is left behind as a ridge of rubble.
Esker-MN
Esker-WI—Note boulders carries by water
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30. Esker- NE WA
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31. Kettles- Large block of ice separates and becomes surrounded with debris
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32.  How is a valley created by a glacier similar to and different from a valley created by a stream?
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33. U Shaped Valleys- Yosemite Valley-
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34. Hanging Valley- Yosemite Natl Park, CA
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35. Holgate Glacier
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36. Glaciers Fusing Yukon Canada
Terminus
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37. Iceberg Calving
Terminus
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38. Portimoreino
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39. Jones Beach NY is part of an outwash plain
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40. Glaciers Video Awsome!
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