GLACIAL LANDFORMS SHAPE MOUNTAINS

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GLACIAL LANDFORMSSHAPE MOUNTAINS

• Surface features
• subglacial
• erosional
• depositional

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1) Glacier travelSurface features

• Crevasses
• V-shaped structures found in the uppermost layer
  of the glacier. WHY?
• brittle deformation
• Rarely gt 20 m deep

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Accumulation area is often heavily crevassed
Direction of flow
New Zealand
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Bergschrund crevasse that separates flowing ice
from stagnant ice at the head of a glacier
Glacier on Shorong Yul-lha, Nepal
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Icefall steep, cracked and jumbled
ice flows over a drop-off - fast moving!!!!
Khumbu Ice fall, Everest
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Ogives alternate bands of light and dark ice on
a glacier
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• Séracs
• Ice towers
• Formed by intersecting crevasses,
• rapid flow
• steep slopes

Glacier des Bossons, French Alps photo MH
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Penitentes spiky columns of snow formed in dry
environments
Nev. Coropuna, Peruvian Andes
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Moulins
Melt stream Glacier can have streams on their
surface!!
water
Very slushy and slippery!!
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SUB-GLACIAL STREAMS
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ICE CAVE AT BOTTOM OF GLACIER
Pastoruri, Peru
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EROSIONAL LANDFORMS OVERVIEW
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CIRQUE

• a semicircular or amphitheater -shaped bedrock
  feature created as glaciers scour back into the
  mountain.
• This is where the snow and ice forming the
  glacier first accumulates.

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HANGING GLACIER
Occur in tributary glaciers, cause spectacular
waterfalls
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ARÊTE

• steep-sided, sharp-edged bedrock ridge formed by
• two glaciers eroding away on opposite sides of
  the ridge

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HORN

• a pyramid-shaped mountain
• peak created by glaciers
• eroding away at different sides
• of the same mountain.

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COL

• a low spot or pass along a cirque or an arete.

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GLACIAL POLISH
Result of abrasion by sand at bottom of glacier
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STRIATIONS

• result of individual particles embedded in the
  glacier scratching the underlying bedrock.

• lines indicate
• the orientation of
• glacial flow.

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NUNATAK

• Peak surrounded by glaciers
• but not itself glaciated

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TARN

• a glacial lake produced by scouring
• often found in cirques.

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U-shaped valleys

• a glacially eroded
• valley
• large, flat valley
• bottom

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ROCHE MOUTONNÉE
sheepback , or sheep rock large rock knob that
resembles a grazing sheep
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DEPOSITION LANDFORMS
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Moraines

• an accumulation of unconsolidated material
• deposited by glaciers
• unsorted material (different sizes of particles)
• particles deposited in moraines
• material has angular edges.

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TERMINAL OR END MORAINE

• deposited at the snout end
• of a glacier
• marks the furthest advance of
• a glacier
• caused as a glacier retreats

End morraine
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LATERAL MORAINE

• unconsolidated material
• deposited along the
• sides of an alpine glacier.

Lateral morraine
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MEDIAL MORAINE
When two alpine glaciers flow together, their
lateral moraines join, forming a medial moraine
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MORAINES OVERVIEW
Medial Moraine
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ERRATICS
Large boulders left by glaciers in areas where
they obviously dont belong. Can be 10s to
100s of kilometers form point of origin
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GLACIER LANDFORMS OVERVIEW