How do Glaciers Effect the Land

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How do Glaciers Effect the Land?

• By erosion deposition

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• Glacial erosion forms when glaciers sculpt, carve
  and carry away the land beneath them.
• Glacial deposition is created by deposition, or
  what a glacier leaves as it retreats or melts
  away.

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Glacial Erosion

• A glacier's weight and movement, can re-shape the
  landscape. (this takes hundreds or thousands of
  years)
• The ice erodes the land surface and carries the
  broken rocks and soil debris away.

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Types of Glacial Erosion

• Glacial Valleys Horns
• Fjords
• Cirques
• Aretes

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Glacial Valleys
Yo

• trough-shaped, with steep vertical cliffs where
  entire mountainsides were removed by glacial
  action.
• Ex Yosemite National Park. glaciers sheared
  away mountainsides, creating deep valleys with
  vertical walls. ?

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Hanging Valley

• Forms when small tributary glaciers join larger
  glaciers
• Since small glaciers are unable to erode down
  into the landscape very far a hanging valley
  formed.
• The larger the glacier, the deeper the valley it
  can erode.

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Look at the hanging valley!
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Fjords

• Long, narrow coastal valleys with steep sides
  rounded bottoms.
• Fjords form when a glacier erodes the land below
  sea level. When the glacier melts, the ocean
  water fills in the valley floor.

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Cirques

• Created when glaciers erode backwards into
  mountainsides, creating rounded hollows shaped
  like shallow bowls.

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Tarn Lake

• A tarn is a mountain lake or pool, formed in a
  cirque after the glacier melts.

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Aretes

• Jagged, narrow ridges created where the back
  walls of two cirque glaciers meet, eroding the
  ridge on both sides.

Arete ?
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Horns

• Created when several cirque glaciers erode a
  mountain until all that is left is a steep,
  pointed peak with sharp, ridge-like aretes
  leading up to the top.

Matterhorn in Switzerland?
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Types of Glacial Erosion
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Glacial Deposition

• Landforms are also created by deposition, or what
  a glacier leaves as it retreats or melts away.
• Kettle Lakes Kames
• Moraines Till Drumlins
• Erratic Boulders

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Till

• Material that is deposited as glaciers retreat,
  leaving behind mounds of gravel, small rocks,
  sand and mud.
• It is made from the rock and soil ground up
  beneath the glacier as it moves.

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Moraines

• Material a glacier picks up or pushes as it
  moves.
• They form along the surface and sides of the
  glacier.
• As a glacier retreats, the ice melts away from
  underneath the moraines, leaving long, narrow
  ridges that show where the glacier used to be.
• Glaciers don't always leave moraines behind,
  because sometimes the glacier's own meltwater
  carries the material away.

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Types of Moraines
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?Medial Moraine
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Kames

• Small steep-sided mounds of soil and gravel that
  form adjacent to the glacier.
• They form from streams flowing out of the glacier
  that carry rock and soil.

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Kettle lakes

• Form when a piece of glacier ice breaks off
  becomes buried by glacial till or moraine
  deposits.
• Over time the ice melts, leaving a small
  depression in the land, filled with water. very
  small, more like ponds than lakes.

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Erratic Boulders

• Glaciers pick up rocks as they slowly move along.
  The glaciers carry the rocks far away from
  their source.
• When glaciers melt they leave behind anything
  they pick up along the way (huge rocks, called
  erratic boulders)

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Drumlins

• long, streamlined tear-drop-shaped formations.
• They form when a glacier deposits material as it
  is flowing and then moves over it.
• Because they are deposited and shaped by glacier
  movement, all the drumlins left by a particular
  glacier will face the same direction.
• Often, groups of several thousand drumlins are
  found in one place, looking very much like
  whalebacks when seen from above.

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Drumlins
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Glacial Striations

• are scratches or gouges cut into the bedrock by
  process of glacial abrasion.