By: Alyssa, Elissa, Jessica, and Kristen

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.