Wind Erosion and Deposition

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Wind Erosion and Deposition
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Erosion

• Erosion is the process that transports Earths
  weathered materials from one place to another by
  wind, water or ice.
• Winds erosional power is much less that water or
  ice but it can move particles uphill.

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Wind Erosion

• Moving air can pick up and transport sediments.
  This is called wind erosion.
• Wind erosion is more likely to occur in areas of
  little vegetative cover and rain.

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Types of Wind Erosion

• Suspension- small particles become airborne for
  long distances.
• Saltation - larger particles are pushed and
  bounced along the ground.This accounts for the
  most wind transport of sand.

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• Deflation is the lowering of the land due to the
  sediments being blown or carried away. Ex. Dust
  bowl
• In the 1930s the Great Plains experienced
  deflation and the areas are today called
  deflation blowouts.

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Wind Erosion continued

• As the wind carries sand this sand can sometimes
  become a process of erosion itself.
• Abrasion is when this sand rub against the
  surface of rocks or other materials.(not limited
  to wind)
• Pitted and grooved areas on a rock are known as
  ventifacts.

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Wind Deposition

• Wind deposition occurs when the wind can no
  longer carry the particles and it drops them.
• A dune is a pile of wind blown sand.

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Dune Types

• There are four types of dunes. They are
• Barchan- Most common- Needs constant wind in same
  direction
• Transverse- Strong winds same direction, abundant
  sand
• Parabolic - Common on coast, moderate winds, some
  veg.
• Longitudinal - wind blowing in two directions,
  limited sand.

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Dune Concerns

• A major concern near coastal areas is that dunes
  are being damaged and destroyed.
• The removal and disturbance of coastal dunes
  leads to
• an increase in beach erosion and
• nearshore flooding

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Dune Migration

• Dune migration is the erosion and deposition of
  an entire dune due to the direction of the wind.
• They can cover roads, houses or other structures
  like the miniature golf course in Kitty Hawk, NC.

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Loess

• A loess is a blanket of wind blown silt.