Erosion Through Wind, Water, Glaciers, and Gravity

Erosion Erosion is the the transportation of weathered material by a mobile agent, such as water, wind, gravity or ice (glaciers). In other words, Erosion MOVES sediments.

Wind Erosion Deflation: lifting and removal of lose particles such as clay and silt. Abrasion: is the mechanical scraping of a rock surface by friction between rocks and moving particles during their transport.

Loess and Sand Dunes Loess is wind blown angular silt that formed from weathering by glaciers or volcanic ash. Sand dunes form on beaches and in deserts when blowing sand is obstructed.

Sand Dunes Dunes can tell you which way the wind was blowing. Windward: Direction wind is blowing from (shallow slope) Leeward: Steep slope where sand is deposited.

Wind Break-Line of trees used to prevent wind erosion.

Glacial Erosion Glacier: A thick, flowing ice mass that forms over the land from the accumulation, compaction, and recrystallization of snow. Glaciers move!!!

Glacial Erosion Glaciers bring rocks and debris with them when they move and these rocks are left behind when the glacier melts. Glacial sediment is called Till. Till is poorly sorted. Wind-blown glacial silt is called loess.

Glacial Erosion

Erratic-Large boulder deposited by a melting glacier.

U-Shaped Valley carved by a glacier

Cirque- A steep, bowl structure