3.2 Wind Erosion and Deposition

By: Alyssa, Elissa, Jessica, and Kristen

What is the difference between deflation and abrasion?

Pick a type of wind erosion and explain it.

Questions To Think AboutSaltation

Deflation

Abrasion

The Process of Wind Erosion

SaltationSaltation: 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.

Deflation=the removal of fine sediment by windDesert Pavement= a surface consisting of pebbles and small broken rocksDeflation Hollows= the depressions from the windWind removes top layerLeaves rock fragmentsMay cause desert pavement Depressions come from wind scooping out scarce vegetation areasDeflation

AbrasionAbrasion 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.

6 Loess

Dunes

The Movement of DunesWind deposition

LoessLoess- very fine sediments deposited by the wind

Areas where loess is present U.S. Midwest Eastern edge of Mississippi Valley Eastern Oregon and Washington

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.

Move in the direction of windsDifferent wind conditions produce various shapes and sizesHas 1 sloped side and 1 steep sloped sideSteep side=slip faceGently sloped side faces windWind constantly transports material up gently sloped sideSand moves over the peak of the dune, slides down slip face, creating steep slopeThe Movement of Dunes

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.Answers to Questions