Dear Tom,
We just returned from a visit to Myrtle Beach, S.C., and the high and low tide lines on the oceanfront sand were easy to see. Does a body of water as “small” as Lake Michigan also experience tides (when the sand isn’t covered by ice, that is)?
The Joynt Family
Dear Joynt Family,
All bodies of water, large and small, are affected by the gravitational pull of the moon and sun, and that applies to the Great Lakes as well. Lake Michigan does experience tides. However, they are minuscule compared to their ocean counterparts.
Tides on Lake Michigan range as much as 1.5 inches in height and, just as on ocean shores, they occur twice daily. Such small variations are masked by wave action at the beaches and by other short-period water-level fluctuations caused by wind and changes in air pressure.
One kind of fluctuation in water levels induced by air pressure is known as a seiche (pronounced saysh). On rare occasions, it can bring a sudden, dangerous rise of several feet on Chicago’s shores. ———-
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