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CH 7.3 Landscapes Shaped by the Wind. Humid areas can resist wind because the moisture holds the soil together. Desert soils are dry and have less vegetation to hold soil in place. Remember the Dust Bowl?. South Dakota before the Dust Bowl. South Dakota after the Dust Bowl. - PowerPoint PPT Presentation
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CH 7.3 Landscapes Shaped by the WindHumid areas can resist wind because the moisture holds the soil together.
Desert soils are dry and have less vegetation to hold soil in place.
South Dakota after the Dust Bowl
Remember the Dust Bowl?
South Dakota before the Dust Bowl
Deflation = lifting and removal of loose particles such as clay and silt.
Saltation = jumping or skipping along the surface.
The wind moves coarse particles along the surface of a desert by saltation.
http://www.weru.ksu.edu/new_weru/multimedia/movies/dust003.mpgWatch this closeup of Saltation!
Blowout = shallow depressions resulting from deflation.
Desert Pavement = surface layers of course pebbles and cobbles that are too heavy for the wind to move.
Wind Abrasion = when wind blown sand cuts and polishes exposed rock.
Can these be the result of wind erosion?
The wind rarely lifts sand more than a meter above the surface of the land.
Wind Deposits: When more is LOESS.
China
Loess = windblown silt that blankets a landscape.
Loess Hills State Forest, Iowa
Loess slides!
Loess crumbles!
The problem of having loess.
Loess sinks!New Madrid Seizmic Zone
Memphis TN
DUNES= sand deposited by winds in mounds or ridges.
Dunes occur in places where the wind encounters an obstruction.
This is a rock.
This is the Wind Direction
This is sand.
The sand builds up then slides.
http://www.fisica.ufc.br/hans/dunes.html
Barchan
NamibiaSanta Maria, CANamibia
Types of Sand Dunes
NamibiaMars
Types of Sand Dunes Longitudinal
Padre Island, TXNorth DakotaArabia
Types of Sand Dunes TransverseMojave, CABrazilNamibiaMorocco
Types of Sand Dunes ParabolicMoroccoNamibia
Types of Sand Dunes BarchanoidMars
LibiaNew Mexico
Mars
Types of Sand Dunes StarColoradoChinaAlgeria
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EXPLORATION LAB CH 7 Interpreting a Glacial Landscape
When you finish the lab, create study cards based on the information on pg 212 following the guidelines on your worksheet.
