Glaciers

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Glaciers

• Ms. Cammarano

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What are Glaciers?

• A large, long-lasting mass of ice which forms on
  the land and moves down slope because of gravity.
  It forms from the compaction and
  re-crystallization of snow.
• They are found in polar regions
• 66.5 - 90 North and South Latitudes

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Ms. Cammarano Hiking Franz- Joseph Glacier in New
Zealand
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Glacier Ice
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Glacier Ice
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How do glaciers move

• Retreat More snow is melting than accumulating.
  The glacier moves backwards.
• Advance More snow accumulates than melts away.
  Gravity will advance the glacier.

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Glacier Retreat
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What do glaciers do to the landscape?

• They form U-shaped valleys, parallel scratches,
  and grooves in the bedrock. Rock become polished.

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Compare Pictures A and B
A
B
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Compare A and B

• What inference can be made as to what happened to
  the glacier from picture A to picture B?
• The glacier retreated.
• Why?
• More snow melted away then accumulated

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Glacier Sorting

• Glacier sediments are Unsorted
• The mass of snow picks up sediment of any size
  and shape and moves the sediment to another
  location (erosion and deposition).
• Example Like rolling a large snow ball to make
  a snowman, the snow ball picks up rocks, dirt,
  and grass.

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Snow Ball- Picking up different sediments
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Unsorted Glacier Sediment (Till)
Boulders
Pebbles
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Unsorted Glacier Sediment
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Appearance of Rocks

• Rocks will become scratched by the glacier
  because of abrasion.
• Striations Parallel scratches in the rock
• They will also become polished