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AEOLIAN PROCESSES. AEOLIAN LANDFORMS. pertain to the activity of the winds and more specifically, to the winds' ability to shape the surface of the Earth and other planets. ERODE. TRANSPORT. DEPOSITS. WIND EROSION. SAND TRANSPORT. DEPOSTION. WIND EROSION. deflation
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AEOLIAN PROCESSES AEOLIAN LANDFORMS
pertain to the activity of the winds and more specifically, to the winds' ability to shape the surface of the Earth and other planets.
ERODE TRANSPORT DEPOSITS WIND EROSION SAND TRANSPORT DEPOSTION
WIND EROSION • deflation • turbulent eddy action of the wind • by abrasion
SAND TRANSPORT suspension saltation creep
SUSPENSION • Small particles are held in the atmosphere • suspend particles less than 0.2 millimeters in diameter
creep • rolling motion (traction) • Slow mass movement of soil downslope.
SALTATION • downwind movement of particles in a series of jumps or skips • lifts sand-size particles no more than one centimeter above the ground
DEPOSITION SAND SHEETS RIPPLES DUNES
SAND SHEETS • are flat • gently undulating sandy plots of sand surfaced by grains • form approximately 40 percent of eolian depositional surfaces
Normal ripples or impact ripples Megaripples Fluid drag ripples or aerodynamic ripples
Normal ripples or impact ripples • occur in the lower part of the lower flow regime sands with grain sizes between 0.3-2.5 mm • have straight or slightly sinuous crests approximately transverse to the direction of the wind.
Megaripples • occur in the upper part of the lower flow regime where sand with bimodal particle size distribution forms unusually long wavelengths of 1-25 m where the wind is not strong enough to move the larger particles but strong enough to move the smaller grains by saltation.
Fluid drag ripples or aerodynamic ripples • are formed with fine, well-sorted grain particles accompanied by high velocity winds which result in long, flat ripples.
DUNES • a hill of sand • occur in different forms and sizes, formed by interaction with the wind • Large dune fields are known as ergs.