Glaciers

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Glaciers

• Changing Earths Surface

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5 Agents of Erosion

• Gravity
• Running Water
• Glaciers
• Waves
• Wind

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Glaciers

• Glacier any large mass of ice that moves slowly
  over land.
• Two Types
• Continental
• Valley

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Continental Glaciers

• A glacier that covers much of a continent or
  large island.

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Ice Age

• Continental glaciers have covered larger parts of
  Earths surface.

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Valley Glaciers

• A long, narrow glacier that forms when snow and
  ice build up high in a mountain valley.

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Valley Glaciers

• Once the depth of the snow and ice reaches more
  than 30-40 meters, gravity begins to pull the
  glacier downhill.

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Valley Glaciers

• Rate a few centimeters to a few meters per day.

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Glaciers Shape the Land

• Erosion
• Deposition

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Glacial Erosion

• Plucking the process by which a glacier picks
  up rocks as it flows over the land.

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Glacial Deposition

• When a glacier melts, it deposits the sediment it
  eroded from the land, creating various landforms.

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Till

• The mixture of sediment that a glacier deposits
  directly on the surface.
• Clay, silt, sand, gravel, and boulders

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Deposition Landforms

• Moraine
• The till deposited at the edges of a glacier
  forms a ridge.
• Terminal Moraine
• The ridge of till at the farthest point reached
  by a glacier
• Long Island NY is a terminal moraine from the
  last ice age.

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Deposition Landforms

• Kettle
• A small depression that forms when a chunk of ice
  is left in glacial till.
• Kettles often fill with water. Many found in
  Minnesota

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