Lake Michigan Coastal Dunes
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Lake Michigan Coastal Dune Home
Introduction to Lake Michigan Coastal Dunes
Features and Types of Dunes
Wind, Sand and Coastal Dunes
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Methods, Results and Research Students
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Basic Processes - Deposition


Deposition occurs when and where the wind velocity drops below the level needed to keep moving particles in motion.

Thus, the threshold velocity for a certain grain size indicates both the wind velocity above which the grains will begin to move and the wind velocity below which the grains will cease to move. (See Entrainment.)

Common reasons for deposition are:

  Example
Change in wind velocity Wind slows down as a storm ends.
Vegetation Beach grass slows down the wind speed near the ground.
Topography Wind velocity slows down on the lee slope of dune.


Sand moving from the southwest (bottom left corner of photo) is deposited among the beach grass of the foredune.
(Hoffmaster State Park in November 2005.)

 

 

 


Basic Processes : previous page / Return to Sand Movement page

 

 

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Last updated 03/23/10.