1. Wind

2. Key Terms for Wind
Define the following key terms in your science journal.
Sand Dune
Deflation
Loess

3. How Wind Causes Erosion
Wind by itself is the weakest form of erosion
Water, waves, moving ice, and mass movements have more effect on the land.
Wind is a powerful force in shaping the land in areas where there are few plants to hold soil in place.
Example:
Deserts- wind can easily move grains of dry sand
Wind causes erosion by deflation and abrasion

4. Erosion by… Deflation What is deflation? Abrasion
When wind removes surface materials
Main cause of erosion
Small particles are picked up and carried through air
Medium sized particles skip or bounce
Large particles slide or roll
Abrasion
Abrasion by wind-carried sand can polish rock but causes little erosion.

5. Wind Deposition Sand Dunes Many shapes and sizes Move over time
All sediment picked up by wind eventually falls to the ground
How? Why?
Wind slows down, sediment hits a boulder, etc.
Wind erosion and deposition may form sand dunes and loess deposits.
Sand Dunes
Many shapes and sizes
Move over time
Little by little the sand shifts with the wind to form different shapes
Roots can anchor dune in one place
Loess Deposits
Sediment is finer than sand- like particles of clay and silt
This fine wind-deposited sediment is call loess
Found in China, Nebraska, South Dakota, etc.