GLACIAL LANDFORMSSHAPE MOUNTAINS

• Surface features

• subglacial

• erosional

• depositional

1) Glacier travel:Surface features

Crevasses: – V-shaped structures

found in the uppermost layer of the glacier. WHY?

– brittle deformation– Rarely > 20 m deep

Accumulation area isoften heavily crevassed

New Zealand

Direction of flow

Bergschrund:crevasse that separates

flowing ice from stagnant

ice at the head of a glacier

Glacier on ShorongYul-lha, Nepal

Icefall: steep, cracked and jumbled ice flows over a drop-off - fast moving!!!!

Khumbu Ice fall, Everest

Ogives:

alternate bands of light and dark ice on a glacier

Glacier des Bossons, French Alps

photo: MH

Séracs:

•Ice towers

•Formed by intersecting crevasses,•rapid flow •steep slopes

Penitentes: spiky columns of snow; formed in dry environments

Nev. Coropuna, Peruvian Andes

Moulins

water

Melt stream: Glacier can have streams on their surface!!

Very slushy and slippery!!

SUB-GLACIAL STREAMS

ICE CAVE AT BOTTOM OF GLACIER

Pastoruri, Peru

EROSIONAL LANDFORMSOVERVIEW

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.

HANGING GLACIER

Occur in tributary glaciers, cause spectacular waterfalls

ARÊTE

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

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

HORN

COL

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

GLACIAL POLISH

Result of abrasion by sand at bottom of glacier

STRIATIONS

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

•lines indicate the orientation of glacial flow.

NUNATAK

•Peak surrounded by glaciers but not itself glaciated

TARN

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

U-shaped valleys

• a glacially eroded

valley

• large, flat valley

bottom

ROCHE MOUTONNÉEsheepback , or sheep rock

large rock knob that resembles a grazing sheep

DEPOSITION LANDFORMS

•an accumulation of unconsolidated material deposited by glaciers

•unsorted material (different sizes of particles) particles deposited in moraines

•material has angular edges.

Moraines

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

TERMINAL OR END MORAINE

End morraine

unconsolidated material deposited along the sides of an alpine glacier.

LATERAL MORAINE

Lateralmorraine

MEDIAL MORAINE

When two alpine glaciers flow together, their lateral moraines join, forming a medial moraine

MORAINES: OVERVIEW

Medial Moraine

ERRATICS

Large boulders left by glaciers in areas where they obviously don’t belong.

Can be 10’s to 100’s of kilometers form point of origin

GLACIER LANDFORMS OVERVIEW