EROISION BY ICE

INTRODUCTION

• Glacier- an enormous mass of slow moving ice
• ~ Capable of eroding, moving, and depositing large amounts of rock material

GLACIERS-RIVERS OF ICE

• Glaciers are created by snow that is deeply packed and becomes ice crystals
• They form in polar regions and where there is high elevation
• Gravity causes them to move slowly like ""rivers of ice""
• There are 2 types they are Alpine and Continental

ALPINE GLACIERS

• Form in mountainous areas
• One common type is a valley glacier
• ~ Gravity pushes down the glaciers making big ""U"" shaped valleys

CONTINENTAL GLACIERS

• Continuous masses of ice that spread across entire continents
• ~ Covers most of Antartica
• About 10,000 years ago a continental glacier covered most of North America
• In some spots they were several kilometers thick

GLACIERS ON THE MOVE

• Slides 2 ways
• ~ Sliding-bottom ice melts
• ~ Flowing-ice crystals grow over each other
• Glacier movement is caused by climate
• ~ Colder temperatures cause glaciers to grow

LANDFORMS CARVED BY GLACIERS

• Continental glaciers smooth the landscape by scraping and eroding
• Alpine glaciers carve out rugged features

DEFINITIONS

• Horns-sharp pyramid-shaped peaks
• ~ Forms when 3 or more glaciers erode
• Cirques-bowl-shaped depressions
• Arêtes-jagged ridges that forms between cirques

DEFINITIONS CONTINUED

• U-Shaped Valleys-forms when a glacier erodes and makes a river valley
• Hanging Valleys-smaller glacier valleys that join deeper main valleys

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