1. Wind Erosion Explain how wind causes deflation and abrasion.
Distinguish how loess and dunes form.

2. Wind Erosion
Different types of erosion.

3. Wind Erosion
Question: How would wind and other types of erosion be different?
Air usually cannot pick up heavy sediments.
Wind carries sediments over large areas.
Wind can place dust high into the atmosphere and thousands of miles away.

4. Wind Erosion
Deflation erosion: Wind erodes loose sediment, such as silt and sand.

5. Wind Erosion
Abrasion Erosion: When windblown sediment strikes rock, the surface of the rock gets scraped and worn away.

6. Wind Erosion
Question: What process do we use that is similar to wind abrasion?
Sandblasting: Machines that use sand and water under high pressure to clean dirt from stone, concrete, or brick.

7. Sandblasting

8. Wind Erosion Sand storms: Most sand storms occur in deserts.
Wind blown sand grains form a low cloud.

9. Reducing Wind Erosion Plant vegetation.
Question: What is the best way to slow or stop wind erosion?
Plant vegetation.

10. Reducing Wind Erosion
Reduce wind erosion by planting wind breaks.

11. Reducing Wind Erosion
Windbreaks: As the wind hits the trees, its energy of motion is reduced. It is no longer able to lift particles.

12. Reducing Wind Erosion
Roots: Especially along sea coast and deserts. Plants with fibrous root systems help stop wind erosion.

13. Deposition by Wind These sediments are eventually deposited.
Question: What happens to sediments that are blown away by wind?
These sediments are eventually deposited.

14. Deposition by Wind

15. Deposition by Wind Loess: Fine-grained sediments deposited by wind.
Many farmlands in the midwest have fertile soil that developed from loess.

16. Deposition by Wind Dune: A mound of sediment drifted by the wind.
Air drops sediment when its energy decreases. Sediment starts to build up behind the object.

17. Deposition by Wind Moving dunes: A sand dune has two sides.
The side facing the wind has a gentler slope. The side away from the wind is steeper.

18. Deposition by Wind
Moving dunes: Unless dunes are planted with grasses, most dunes will move away from the direction of the wind.
Some dunes are known as traveling dunes because they move rapidly across desert areas.