Glaciers Carve Land and Move Sediments

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Glaciers Carve Land and Move Sediments

• Section 5.4

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Explore Glaciers pg 165

• What happened when the ice cube was dragged
  across the clay?
• What happened to the sand and gravel in the ice
  cube as it melted?

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Extent of Glaciers

• Glaciers are
• In mountain ranges around the world
• In land regions at North Pole and South Pole
• 10 of Earths surface TODAY
• Used to be 30 30,000 years ago

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2 Types of Glaciers

• Alpine Glaciers
• Called valley glaciers
• Can cause a V shaped mountain valley to become a
  U shaped valley
• If an alpine glaciers flows into an ocean, blocks
  can break off and form an iceberg!

• Continental Glaciers
• Called ice sheets
• Cover Greenland
• Cover Antarctica

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2 Types of Glaciers..continued

• Where do each of the two types of glaciers form?

• Alpine glaciers form in mountains and flow into
  valleys.
• Continental glaciers form on large landmasses
  (continents) near the poles (North/South).

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Glacier large mass of ice that moves over land

• Alpine Glacierwhat are the dark lines?
• These are rocks picked up by the glacier along
  its route.

Continental Glacier
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Why are the cracks shown near the surface of the
glacier and not at the bottom?

• At the bottom.The ice is under somuch pressure
  thatit flows instead ofcracking.not asmuch
  pressureon the top so itcracks.

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How is an alpine glacier like a plow?

• The glacier
• Scoops up rock and soil
• Picks rocks from the sides of valleys
• Sediment moves with it

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Whats left behind?

• Till the sediment left on the ground by a
  retreating glacier.
• Moraine a deposit or hill of till
• AND..

Moraine at Mono Lake, California, United States
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Whats left behind?

• Kettle Lakes bowl depression that was once
  filled in with ice that has melted after the
  glacier retreated.

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Section Review page 170

• 1. List 2 processes that cause glaciers to move.
• Gravity
• Water making the bottom slippery will cause
  flowing and sliding

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Section Review page 170

• 2. What are the two major types of glaciers and
  where are they found?
• Alpine and found in mountain valleys
• Continental and found in Antarctica and Greenland

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Section Review page 170

• 3. Describe the land features left behind by
  glaciers that have melted and shrunk.
• Glaciers leave
• U-shaped valleys
• Moraines
• Abrasions
• Till
• Kettle lakes

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Section Review page 170

• 4. Identify two ways in which the erosion
  effects of glaciers differ from those of rivers.
• a. Glaciers crush and move large rocks
• Rivers move smaller sediments
• b. Glaciers pile up moraines, etc
• Rivers create sandbars, meanders, and deltas

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Section Review page 170

• 5. How would glaciers be affected by changes in
  climate, such as global warming and global
  cooling?
• Warming melts glaciers and shrinks ice sheets
  (continental glaciers)
• Cooling causes glaciers to expand and form in new
  places.

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Section Review page 170

• 6. Regions near the equator are generally the
  warmest on Earth. However, in one small area of
  Africa, there are glaciers close to the equator.
  Form a hypothesis to explain why these glaciers
  exist.16
• IF there are glaciers in Africa near the equator,
  
• THEN they are in the high mountains
• BECAUSE high mountains could be cold enough for
  glaciers.