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
Climate, Dune, Lake and Seasonal Factors
Methods, Results and Research Students
References and Links to More Information


Dunes - Active foredunes

When the incipient foredune reaches a height of roughly 0.5 m (1.5 ft), the dune itself becomes an obstacle to the wind. The dune continues to grow as wind-blown sand from the beach is deposited on the dune. Vegetation such as American beachgrass (Ammophila breviligulata) grows up through the deposited sand to anchor the dune sand and cause further deposition.

Foredunes of 1-1.5 m height (3-5 ft) may be tall enough to trap all the wind-blown sand from the beach. At this point, inland dunes or structures do not receive wind-blown sand from the beach.

Two foredunes: the foredune closest to Lake Michigan is beginning to cut off the sand supply to the larger inland foredune.
(Hoffmaster State Park in December 2003.)

Foredunes continue to grow as long they receive wind-blown sand. Growth stops when the sand supply is cut off, either by a new foredune growing between the original foredune and the beach or when the lake level rises so that waves cover the beach.

Foredunes: previous page / next page / return to Hoffmaster dunes


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Last updated 03/23/10.