10.2 Wind Erosion and Deposition

What are some of the forces that help shape the landscape?

Saltation The skipping and bouncing movement of sand-sized particles in the direction that wind is blowing. The skipping and bouncing movement of sand-sized particles in the direction that wind is blowing.

Deflation The removal of fine sediment by wind. The removal of fine sediment by wind. Causes the formation of desert pavement (a surface that is made of pebbles and small, broken rocks.). Causes the formation of desert pavement (a surface that is made of pebbles and small, broken rocks.). Deflation hollows – the depressions in the landscape that the wind may scoop. Deflation hollows – the depressions in the landscape that the wind may scoop.

Abrasion The grinding and wearing down of rock surfaces by other rock or by sand particles. The grinding and wearing down of rock surfaces by other rock or by sand particles.

Describe three different ways that wind shapes landscapes. In saltation, sand skips and bounces in the direction of the wind. In deflation, fine sediment is removed by the wind. In abrasion, rock surfaces are worn down by other rock or sand particles.

Wind-Deposited Materials Wind carries sediment. Wind carries sediment. When wind slows it drops the heavier materials first. When wind slows it drops the heavier materials first.

Dunes Mounds of wind- deposited sand. Common in sandy deserts. Monterey Bay Dunes, Algodones Sand Dunes. Algodones Sand Dunes Monterey Bay Dunes

Movement of Dunes Move in the same direction the wind blows. Gentle slope side faces the wind. Other side is steep (slip face).

How are dunes an example of wind shaping landscapes? Dunes move in the direction of strong winds. Wind shapes the landscape by constantly shaping dunes. Wind constantly transports sand up the side of a dune and moves the sand over the crest, where the sand slides down the slip face of the dune.

Wind

Review Questions 1. Compare saltation with deflation. Saltation moves larger particles along the ground, while deflation picks up the removes finer sediments. 2. Explain the process of abrasion. Abrasion is the wearing down of rock surfaces by other rock or sand particles. In areas that have strong winds and loose sand, the collision of millions of sharp sand grains grinds and wears down rock surfaces.

3.How do dunes form? When wind encounters an obstacle, it slows down and drops its heaviest materials. These deposits of materials grow to form a mound. When these mounds are composed of sand, they are called dunes. 4.If you climbed up the steep side of a sand dune, did you most likely travel in the direction that the wind was blowing? No, the gently sloped side generally faces the wind. The steep side, or slip face, generally faces away from the wind. If you climb up the steep slope, you will generally be climbing against the wind.

5.Wind erodes particles in one area and deposits them elsewhere. Which would be deposited farthest from its source: sand or dust. Dust is the lighter material, so it would be carried farther by the wind than sand is.