Wind, Ice, and Gravity Erosion

Wind Erosion Wind is an agent of erosion when it moves soil, sand, and rock particles. Wind erodes rock by: abrasion deflation

Types of Wind Erosion Abrasion: the grinding and wearing down of rock surfaces by other rock material Deflation: the removal of fine sediment by wind

Deflation

Landforms Caused by Wind Dunes: mounds of wind deposited sands

Landforms Caused by Wind Loess: thick deposits of windblown, fine-grained sediments Fine grains blown far and high. Deposited far from source. Builds up over thousands of years.

Ice Erosion Glacier: large mass of moving ice that form from the compacting of snow by natural forces Glacial Drift: general term for all materials carried and deposited by glaciers

Types of Glaciers Alpine Glacier: forms in a mountainous area, forms rough land features Continental Glacier: thick sheet of ice that spread over large areas, form smooth land features

Landforms Caused by Alpine Glaciers Cirque: bowl shaped depression at head of valley Arete: sharp ridges forming between two cirques Horn: when three or more aretes form a sharp peak

Landform Caused by Continental Glaciers Moraine: sediments carried and deposited at the edge of the glacier Esker: long ridge of sediment deposited from glacier

Glaciers http://www.brainpop.com/science/earthsystem/glaciers/ http://mrbdc.mnsu.edu/sites/mrbdc.mnsu.edu/files/public/mnbasin/flash/glaciers/glaciation_animation.html

Glaciers in Minnesota

Gravity Erosion Mass Movement: shifting of materials due to gravity Causes rock and soil to move downslope.

Slow Mass Movement Creep: extremely slow movement of material downhill

Fast Mass Movement Rockfall: loose rock falls down a steep slope Landslide: sudden and rapid movement of large amounts of material down a slope Mudflow: rapid movement of large amount of mud

http://www.phschool.com/atschool/phsciexp/active_art/mass_movement/index.html