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Strategic plan targets invasive species
The Superior Daily Telegram (11/17)
Douglas County’s Land Conservation Committee is forwarding a plan to the county board that takes aim at invasive species.
Mich. Clean Marina Program: Public-private partners work together to improve water quality
Grand Rapids Environmental News Examiner (11/9)
Partners from the public and private sector in Michigan are working together in a voluntary program to improve the quality of the Great Lakes.
Researchers seek funding for wind test site in Lake Michigan
Grand Rapids Environmental News Examiner (11/7)
In a recent article in The Muskegon Chronicle, it was reported that researchers at Grand Valley State University’s Michigan Alternative and Renewable Energy Center (MAREC) cited a lack of year-around data (on wind platform testing) needed by prospective development companies.
COMMENTARY: Senate needs to pass clean energy act to help Michigan
The Grand Rapids Press (10/26)
Senate Majority Leader Harry Reid was absolutely correct with his recent proclamation about the current condition of the Great Lakes State: "The State of Michigan," Reid declared from the Senate Floor, with a copy Time Magazine in his hand, "is in trouble."
First Nation women 'walk the environmental talk'
WeNews (10/23)
Tomorrow's global day of climate activism aims for media and political attention. First Nation women have another way. Since 2003, they've walked the shoreline of a Great Lake or major river, meditating on the needs of an unborn generation.
City making big push for water school
The Business Journal (10/23)
The push is on to convince the University of Wisconsin-Milwaukee that the best location for its new School of Freshwater Sciences is near the university’s existing Great Lakes Water Institute on East Greenfield Avenue.
What's going on in your neighborhood this month? Meet other people and learn together at recreational and educational events! Our new dynamic calendar is updated daily with current educational events.
2 | Three types of water level fluctuations
Water levels on the Great Lakes change seasonally each year and can vary dramatically over longer periods. Short-term changes are generally of greater magnitude than the monthly averages.
Short-term changesSome water level fluctuations are not a function of changes in the amount of water in the lakes, but are due to winds or changes in barometric pressure. These short-term fluctuations, often due to storms or ice jams, can last from a couple hours to several days and can be very dramatic.
One such phenomenon, known as wind set-up or storm surge, occurs
when sustained high winds from one direction push the water level up at one end of a
lake, which makes the level drop by a corresponding amount at the opposite end. Changes
in barometric pressure can add to this effect. When the wind abruptly subsides or
barometric pressure changes rapidly, the water often oscillates until it stabilizes again.
This oscillation is called seiche (pronounced "sayshe"). These events are most common on Lake Erie
due to its east-west orientation in an area of prevailing westerly winds and its generally
shallow western end.
See also: Great Lakes Facts and Figures
Seasonal changes
In the fall and early winter, when the air above the lakes is cold and
dry and the lakes are relatively warm, evaporation from the lakes is greatest.
Consequently, water levels decline to their seasonal lows.
As the snow melts in the spring, runoff to the lakes increases. Evaporation from the lakes is also least in the spring and summer when the air above the lakes is warm and moist and the lakes are cold. With more water entering the lakes than leaving, water levels rise to their peak in the summer. In the early fall, evaporation and outflows again begin to exceed the amount of water entering the lakes.
The range of seasonal water level fluctuations on the Great Lakes averages about 12 to 18 inches from winter lows to summer highs. Seasonal rises begin earlier on the more southern lakes that experience a slightly warmer climate. Lake Superior, the northernmost lake, is generally the last to peak, usually in August or September.
Long-term changes
Long-term fluctuations occur over periods of consecutive years.
Continuous wet and cold years will cause water levels to rise. Likewise, consecutive warm
and dry years will cause water levels to decline. Over the last century, the range from
extreme high to extreme low water levels has been nearly 4 feet for Lake Superior and
between 6 and 7 feet for the other Great Lakes.
Graphic: Lake profile showing wind set-up.
