All Waves Are Not Created Equal
FORT MYERS, FL - All waves are not created equal. The waves encountered in the Great Lakes differ from those found in the nation's oceans. One of the main differences is the Great Lakes waves do not get as large as those in the ocean, because the Great Lakes have a smaller surface area and are shallower.
"But don't let that fool you," says Scudder Mackey, Ph.D., an environmental consultant in the Chicago area. "Especially in the central parts of the lakes, storms can be quite severe and the waves can become quite large.
The size of waves in the Great Lakes depends on the strength of the wind and the distance the wind blows across the water. "So strong winds traveling long distances generate large waves," Mackey explained. "The orientation of the lake matters, as well. For example, Lake Michigan, which has a north-south orientation, can experience very large wave activity from winds coming out of the north or south."
Because the lakes are shallower, the waves are have shorter wave lengths and are steeper, especially in shallow-water areas. This, combined with storms that can blow up quickly with little warning, creates hazardous conditions for Great Lakes boaters and coastal property owners.
The Great Lakes are the largest fresh-water bodies in the world, accounting for 23 percent of the world's fresh water supply.
Mackey and other scientists say climate change is affecting the Great Lakes as well as the oceans. "Long-term models are predicting more frequent and significant storm events on the Great Lakes, which will generate more significant waves," he explained. "That's going to be of importance to boaters and coastal property owners over the next 15-30 years."
Another change scientists are observing is a general warming in the winter months - the ice is forming later in the fall and disappearing earlier in the spring. This is a problem because the ice provides natural stabilizing shore protection. The less ice cover, the greater the potential for waves to cause damage on the shoreline.
Many of the Great Lakes' coastlines are highly developed, and there is a significant amount of economic activity associated with them. "Coastal residents and business owners on Great Lakes shorelines may want to consider how these more frequent and severe storms will impact their homes and businesses in the future," Mackey said.
(Printed courtesy of the American Shore and Beach Preservation Association.)
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