glacial landform

Evidence for GlaciersEvidence for GlaciersErraticsErraticsStriationsStriationsPolished BedrockPolished Bedrock

Erratic

ErraticErratic Boulder-sized rock Boulder-sized rock

dumped by a dumped by a glacierglacier

Rock is different Rock is different type than type than surrounding rockssurrounding rocks

Striations

Striations/ Chatter marksStriations/ Chatter marks Grooves carved Grooves carved

into bedrockinto bedrock Formed by Formed by

abrasive action of abrasive action of cobbles and cobbles and pebbles carried at pebbles carried at bottom of glacierbottom of glacier

Direction of Direction of scratches shows scratches shows direction glacier direction glacier movedmoved

Glacial polishGlacial polish Smooth rock Smooth rock

surfacessurfaces Created as glaciers Created as glaciers

flow over bedrockflow over bedrock

Glacial Pavement….Glacial Pavement….

Luis María Benítez.

Source unknown

ZONE OF

ACCUMULATION

ZONE OF

ABLATION

The Upper Grindelwald Glacier and the Schreckhorn, in the Bernese Oberland, Switzerland.

Adrian Pingstone

crevassecrevassessA great fissure or A great fissure or

crack in a glacier.crack in a glacier. They can be more than 30 m deep They can be more than 30 m deep

The Perito-Moreno Glacier, Argentina

TOP LAYER OF GLACIER CAN FRACTURE…..BRITTLE BEHAVIOR

FROMS CREVASSES

http://www.chmouel.com/geeklog/gallery/gallery_individual.php/argentina/8.html

Original valley (V-shaped)

Glaciers come and alter landforms

Glaciers retreat and newfeatures appear

Landscape Features- Landscape Features- Valley GlaciersValley Glaciers

CIRQUESCIRQUES: : semi-circular shaped bedrock feature semi-circular shaped bedrock feature created as a glacier scours back toward the mountaincreated as a glacier scours back toward the mountain

ARÊTESARÊTES: : steep-sided, sharp-edged bedrock ridgesteep-sided, sharp-edged bedrock ridge formed by two glaciers eroding away formed by two glaciers eroding away

on opposite sides of a ridgeon opposite sides of a ridge

CIRQUE

TARN

TARNS:TARNS:glacial lakes glacial lakes produced by glacial scouringproduced by glacial scouringoften found in cirquesoften found in cirques

HORNSHORNS:: 3 or more cirques adjacent to one 3 or more cirques adjacent to one

anotheranother

Hanging Valley

ARÊTE CIRQUE

HANGING VALLEY

U-SHAPED VALLEY

U-shaped valley

tilltillUnsorted and Unsorted and unstratified rock unstratified rock material deposited material deposited dirtectly by glacial dirtectly by glacial ice.ice.

Landforms made from Landforms made from glacial till are called glacial till are called moraines. moraines.

Glacial till sediment, in some places hundreds of feet thick, covers most of New York State.

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All the ‘stuff’ that’s pushed out of the way by the glacier gets piled up in a big heap,

called moraine.

Terminal moraine

Lateral moraine

Medial moraine

Lateral moraine

Dirk Beyer

Lateral moraine

Image by Michael Collier

Medial MoraineMedial Moraine

MorainesMoraines Chugach Chugach

Mountains, Mountains, AlaskaAlaska

Image by Bruce Molnia, Terra

Photographics

MORAINESMORAINES: material left behind : material left behind when glacier recedeswhen glacier recedes

Kettle Lake

Till

Drumlins

Terminal MoraineGlacial Stream

Moraine-dammed lake

Outwash

plain

Esker

Drumlin

drumlins

Kettle Lakes

eskereskerA long, winding A long, winding ridge formed ridge formed when sand and when sand and gravel fill gravel fill meltwater meltwater tunnels tunnels beneath a beneath a glacier.glacier.

Eskers

kamekame A small, cone-A small, cone-shaped hill of shaped hill of stratified sand stratified sand and gravel and gravel formed at a formed at a glacial front by glacial front by meltwater meltwater carrying carrying sediment off sediment off the glacier’s the glacier’s surface.surface.

http://www.env.duke.edu/eos/geo41/gla2.htm

KAME (WISCONSIN)

Have sorted sediments

outwashoutwash

When a When a glacier glacier melts, melts, its rock its rock load load remains remains in nearly in nearly the the same same place as place as in the in the glacier.glacier.

Outwash plainOutwash plainAn outwash An outwash plain will be plain will be crossed by crossed by many many meltwater meltwater streams. streams.