1. By: Alyssa, Elissa, Jessica, and Kristen

2. Questions To Think About
What is the difference between deflation and abrasion?
Pick a type of wind erosion and explain it.

3. The Process of Wind Erosion
Saltation
Deflation
Abrasion

4. Saltation
Saltation: it is the skipping and bouncing movement of sand-sized particles in the direction the wind is blowing.
Moving sand particles knock into each other, making other grains bounce and roll.
Areas that get strong winds experience saltation.

5. Deflation Deflation=the removal of fine sediment by wind
Desert Pavement= a surface consisting of pebbles and small broken rocks
Deflation Hollows= the depressions from the wind
Wind removes top layer
Leaves rock fragments
May cause desert pavement
Depressions come from wind scooping out scarce vegetation areas

6. Abrasion
Abrasion is the grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles.
This happens mostly in places that have strong winds, soft rocks, or loose sands.
Abrasion helps smooth out and shape rocks, like the one shown.

7. Wind deposition
Loess
Dunes
The Movement of Dunes

8. Loess Loess- very fine sediments deposited by the wind
Areas where loess is present
U.S. Midwest
Eastern edge of Mississippi Valley
Eastern Oregon and Washington

9. Dunes
Dunes: a mound of wind-deposited sand that keeps its shape even though it moves
When the wind hits an obstacle, it slows and drops the heavier material it was holding beforehand.
As there is more material building up, it is completely covered, forming a mound.
Dunes move in the direction of stronger winds but still keep their shape.
Dunes have a steep side, called a slip face, and a gently sloped side usually facing the wind.
Sand moves over the peak of the dune from the gently sloped side and thus forms a steep side.

10. The Movement of Dunes Move in the direction of winds
Different wind conditions produce various shapes and sizes
Has 1 sloped side and 1 steep sloped side
Steep side=slip face
Gently sloped side faces wind
Wind constantly transports material up gently sloped side
Sand moves over the peak of the dune, slides down slip face, creating steep slope

11. Answers to Questions
1q) What is the difference between deflation and abrasion? 1a) The difference between abrasion and deflation is that abrasion deals with the grinding and wearing away of rock surfaces, while deflation deals with the blowing away of dry soil particles. 2q) Pick a type of wind erosion and explain it. 2a) Example: Saltation is the movement of sand by short jumps and bounces that is caused by wind or water.