Wind. Wind is different than water when it comes to erosion. Why? Wind can carry small materials...
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Transcript of Wind. Wind is different than water when it comes to erosion. Why? Wind can carry small materials...
Wind is different than water when it comes to erosion.
Why?
Wind can carry small materials uphill/upslope
Generally, most of the movement of materials by wind occurs in areas of low precipitation, and minimal plant growth
Rule of Thumb
Desert pavement is what is left when steady winds have removed small particles and leave
larger particles
Abrasion is the process of wind blown particles wearing away at surfaces of rocks and other
features
Flute-like textures on the rock, possibly caused by wind abrasion, are clearly visible.
This process works because most of the sand particles are made of quartz that is
quite hard
Polishing of rocks can take place because of this process
Sandblasting and Abrasion
• Wind can only lift sand to about 1 meter high - results in “Mushroom Rock”
• Frosted or Pitted sediments – rocks with flat sides
Wind Deposition
Sand and sediments accumulate around objects that break the flow of wind
Vegetation helps do this!
SAND DUNESare ridges of wind deposited sand
- Usually 3 to 15 metres high, but can reach 180 metres
- A continuously changing dune is ACTIVE Corbis Digital Stock
Dune conditions are dependent on the following
Availability of sandWind velocityWind direction
Vegetation present
2.) PARABOLIC DUNES- crescent-shaped but with the concave side on the windward side- usually elongated- may develop in associated with deflation hollows
Wind direction
3.) TRANSVERSE DUNES• low sand ridge at right angles to the wind direction• may form because of large amounts of sand
wind
4.) LONGITUDINAL DUNES
• low sand ridges parallel to the wind direction• may form because of a limited amount of sand• also known as seif dunes
wind
Loess
Silt and clay particles that are deposited by the wind
Wisconsin is a state that has large buildups of loess
LOESS• Finely textured sediment wind-blown long distances
• Wind-blown glacial debris formed large deposits