Wind SWBAT describe conditions that contribute to the likelihood that an area will experience wind erosion; identify wind-formed landscape features; describe how dunes form and migrate; explain the effects of wind erosion on human activities

What is unusual about the surface of these rocks? What do you think shaped these rocks?

Wind Erosion and Transport Two methods for wind to move sand Suspension Wind lifts and keeps the particles airborne for a long distance Saltation Particles bounce along the ground

Wind Erosion and Transport Where does wind erosion primarily occur? Wind erosion is most common in areas with little vegetative cover, semi-arid areas, as well as seashores or lakeshores

Wind Erosion and Transport Deflation The lowering of the land surface as a result of surface particles being removed by wind Abrasion Occurs when particles such as sand rub against the surface of rocks or other materials

Wind Erosion and Transport Why is sand such an effective agent of wind erosion? Sand is generally made up of quartz, which is a very hard mineral that can scratch away at surfaces Ventifacts Rocks shaped by wind blown sediments

Wind Deposition How is wind deposition similar to water deposition? They both erode sediments, and the sediments are dropped when they slow down Dune A pile of wind-blown sand that accumulates on an object

Dune Formation What conditions determine a sand dunes shape? Sand availability Wind velocity Wind direction Amount of vegetation

Dune Formation Barchan Transverse Parabolic Longitudinal Solitary, crescent-shaped dunes Form in flat areas with little vegetation Long series of ridges that are perpendicular to the wind Form in areas with lots of sand and strong steady winds Form in humid areas between clumps of plants U shaped Long series of ridges that are parallel to the wind Form in areas with limited sand and strong prevailing winds

Wind Deposition Loess Thick wind blown deposits of silt and fine sediment

Get Your Lab Notebooks In your groups complete the minilab on page 194 Title: Where does wind erosion occur Using the map on page 192, answer the 3 analyze and conclude questions in complete sentences. When you finish you may start the assessment questions 1-6 on page 197, you may work in your groups