Erosion by Ice 2/4/15Erosion by Ice 2/4/15
12-3 pgs. 309-31512-3 pgs. 309-315
IN: Explain the processof saltation.IN: Explain the processof saltation.
Terms to Learn & ObjectivesTerms to Learn & Objectives
Terms:Terms:
glaciericebergcrevasseglacial driftstratified drifttillglaciericebergcrevasseglacial driftstratified drifttill
Objectives:Objectives:
•Summarize why glaciers are importantagents of erosion and deposition.•Summarize why glaciers are importantagents of erosion and deposition.
•Explain how ice in a glacier flows.•Explain how ice in a glacier flows.
•Describe landforms that are deposited anderoded by glaciers.•Describe landforms that are deposited anderoded by glaciers.
Glacier – an enormous mass of movingice.Glacier – an enormous mass of movingice.
How do glaciers form?How do glaciers form?
Glaciers are very heavy which means:Glaciers are very heavy which means:
They have the ability to move across theEarth’s surface.They have the ability to move across theEarth’s surface.
They are capable of eroding, moving, anddeposition large amounts of materials.They are capable of eroding, moving, anddeposition large amounts of materials.
Alpine GlaciersAlpine Glaciers
Form in mountainous areas.Form in mountainous areas.
Create U-shaped valleys.Create U-shaped valleys.
Yosemite Valley
Continental GlacierContinental Glacier
Huge continuous masses of ice thatcontinue to get larger.Huge continuous masses of ice thatcontinue to get larger.
Smooth and flatten the landscape.Smooth and flatten the landscape.
Ice Sheet of Greenland
Ice ShelfIce Shelf
An area where the ice is attached to theice sheet but is resting on open water.An area where the ice is attached to theice sheet but is resting on open water.
Icebergs – Large pieces of ice thatbreak off an ice shelf and drift into theocean.Icebergs – Large pieces of ice thatbreak off an ice shelf and drift into theocean.
Glaciers on the MoveGlaciers on the Move
When enough ice builds up on the slope,the ice begins to move downhill.When enough ice builds up on the slope,the ice begins to move downhill.
The thickness of the ice and the steepnessof the slope determine how fast a glacierwill move.The thickness of the ice and the steepnessof the slope determine how fast a glacierwill move.
An alpine glacier is estimated to bemoving forward at 5 meters per day.An alpine glacier is estimated to bemoving forward at 5 meters per day.
As the glacier moves, the rock piecesscrape and polish the surface rock.As the glacier moves, the rock piecesscrape and polish the surface rock.
Larger rocks embedded in the glaciergouge out grooves called striations.Larger rocks embedded in the glaciergouge out grooves called striations.
Crevasse – a large crack that formswhere the glacier picks up speed orflows over a high point.Crevasse – a large crack that formswhere the glacier picks up speed orflows over a high point.
Landform Carved by AlpineGlaciersLandform Carved by AlpineGlaciers
Cirques are bowl-like depressions where glacierice cuts back into the mountain walls.Cirques are bowl-like depressions where glacierice cuts back into the mountain walls.
Arêtes are jagged ridges that form between twoor more cirques cutting into the same mountain.Arêtes are jagged ridges that form between twoor more cirques cutting into the same mountain.
Horns are pyramid-shaped peaks that form whenthree or more cirques erode the mountain.Horns are pyramid-shaped peaks that form whenthree or more cirques erode the mountain.
Matterhorn, Switzerland
Landforms Carved by ContinentalGlaciersLandforms Carved by ContinentalGlaciers
Glacial drift – the material carried anddeposited by glaciers.Glacial drift – the material carried anddeposited by glaciers.
Stratified drift – rock material that hasbeen sorted and deposited in layersby water flowing from the melted iceof a glacier.Stratified drift – rock material that hasbeen sorted and deposited in layersby water flowing from the melted iceof a glacier.
Till – unsorted rock material that isdeposited directly by glacial ice whenit melts.Till – unsorted rock material that isdeposited directly by glacial ice whenit melts.
Moraines are ridges of till that formalong the edges of glaciers.Moraines are ridges of till that formalong the edges of glaciers.
1. Lateral Moraines 2. Ground Moraines 3. Terminal Moraines
OUT: Explain why continentalglaciers smooth thelandscape and alpineglaciers create a ruggedlandscape.OUT: Explain why continentalglaciers smooth thelandscape and alpineglaciers create a ruggedlandscape.