| Seasonal
Changes |
| There is a
distinctive seasonal pattern to Lake Michigan coastal dunes because
wind, vegetation and surface conditions change throughout the year.
The illustration below shows how a foredune changes through one year.
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Summer
The foredune does not change
much during the summer because most summer winds are too weak to move
sand. |
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Autumn
Strong westerly winds in
autumn storms move sand from the beach to the foredune where it is
trapped by vegetation. |
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Winter
Strong winter winds move
sand and snow from the beach to the foredune. The wind-blown sand
travels further across the dune as the dune vegetation is buried.
Frozen dune slopes can have steep angles. |
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Spring
As snow and ice melt, new
sand deposits settle down on dune slopes. Vegetation such as American
beach grass sends shoots up through the deposits. |
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Illustrations
by Jody Brown |
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