Glaciers & ErosionGlaciers & Erosion

Glaciers: What are they?Glaciers: What are they?

very powerful agent of erosionvery powerful agent of erosionmass of moving icemass of moving ice

How are glaciers formed?How are glaciers formed?

when snow and ice accumulate to a great when snow and ice accumulate to a great enough thickness and move down slope enough thickness and move down slope due to gravity.due to gravity.

Types of Glaciers:Types of Glaciers:

Alpine Glacier- formed in mountainous Alpine Glacier- formed in mountainous regions.regions.

Continental Glaciers- covers large land Continental Glaciers- covers large land areas. (Greenland & Antarctica)areas. (Greenland & Antarctica)

Norris & Taku Glaciers, Tongass National Norris & Taku Glaciers, Tongass National Forest, Alaska.Forest, Alaska.

How do glaciers move?How do glaciers move?

on average, glaciers only move approx. on average, glaciers only move approx. 100 meters per year…some more, some 100 meters per year…some more, some less.less.

Basal SlipBasal Slip

Internal Plastic FlowInternal Plastic Flow

Glacial Features and Landforms:Glacial Features and Landforms:

crevassescrevasses

icebergsicebergs

cirquecirque

arêtesarêtes

hornhorn

hanging valleyhanging valley

Canol Mountain Cirque GlacierCanol Mountain Cirque Glacier

Hanging Valley National ParkHanging Valley National Park

New ZealandNew Zealand

Glacial Features Left From Deposition:Glacial Features Left From Deposition:

erraticserratics

morainesmoraines

kettleskettles

great lakesgreat lakes

salt lakessalt lakes

fjordsfjords

Erratic from a glacial Erratic from a glacial ice sheet, Canada.ice sheet, Canada.

Fjord- formed from glacier filling up with sea Fjord- formed from glacier filling up with sea water.water.