Erosion by Glaciers

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Erosion by Glaciers
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A glacier is

• any large mass of ice that moves slowly over land

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Glaciers form

• in areas where more snow falls than melts.

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What are 2 types of glaciers?

• Continental Glaciers
• Valley Glaciers

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Continental Glaciers

• Def glacier that covers much of a continent
• Location Today
• Covers 10 of Earth
• Greenland and Antarctica
• Past Ice Ages when large parts of Earth were
  covered with Continental glaciers

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Valley Glaciers

• Def a long narrow glacier that forms when snow
  and ice builds up in a mountain valley
• Location Today
• Held in by sides of the mountain (Andes)
• Past Form U-shape valleys show where Valley
  glaciers once slid down from a mountain

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Continental Valley Glaciers

• Large masses of ice
• Move slowly on land
• Shape the land

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How do glacier shape the land?Glaciers move due
to the force of gravity.
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Plucking

• The process by which a glacier picks up rocks as
  it flows across the land.

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Abrasion

• As a glacier drags the rock along, the land is
  gouged scratched

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Till

• Deposits of sediments left behind as a glacier
  melts (clay, silt, sand, gravel, boulders)

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Moraine

• Ridge that forms by the till deposited at the
  edge of a glacier
• Example
• Long Island
• in NY is a
• terminal
• moraine

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Kettles

• Small depressions left in areas when chunks of
  ice are left in glacial till
• They fill in with water and form ponds or
• lakes
• Common in
• Minnesota

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• Brainpop on Glaciers and Ice Ages
• http//www.brainpop.com/science/earthsystem/glacie
  rs/