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Funding milestone reached for Aquatic Research Lab expansion
The Sault Ste. Marie Evening News (6/13)
Both houses of Michiganís legislature have approved nearly $9 million in funding for an expansion of Lake Superior State Universityís successful Aquatic Research Lab (ARL).

Students dive, document Sheboygan shipwreck
Sheboygan Press (6/13)
A team of budding nautical archaeologists from East Carolina University dove below the waves of Lake Michigan to discover what treasures lay hidden on the sandy bottom.

Island living and working at Thousand Islands Biological Station in Clayton
The Syracuse Post-Standard (6/8)
Many apply, but few are chosen for the limited number of scientific research positions each year at the Thousand Islands Biological Station (TIBS). The SUNY ESF research facility is located on Governor's Island in the St. Lawrence River in Clayton, NY.

Gems emerge in eel study
The Cornwall Standard Freeholder (5/31)
In Ontario, an ongoing study of American eel habitat on the St. Lawrence River has a preeminent biology professor and masters student charting some uncharted waters in fisheries research.

Lake Superior State celebrating 30 years of salmon releases
The Associated Press (5/29)
In Michigan, the Aquatic Research Laboratory at Lake Superior State University is celebrating three decades of raising and releasing Atlantic salmon in the St. Marys River.

TEACH Calendar of Events
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.
Water levels on the Great Lakes

table of contents
Introduction
Three types of water level fluctuations
History repeating itself: Hydrographs illustrate historical levels
How levels and flows are measured
Effects of lake level fluctuations
References and more information

Water levels on the Great Lakes

Click to see larger image. Water levels are part of the ebb and flow of nature.

The difference between the amount of water coming into a lake and the amount going out is the determining factor in whether the water level will rise, fall or remain stable. When several months of above-average precipitation occur with cooler, cloudy conditions that cause less evaporation, the levels gradually rise. Likewise, prolonged periods of lower-than-average precipitation and warmer temperatures typically result in lowering of water levels.

The recent decline of Great Lakes' water levels, now at lows not seen since the mid-1960s, is due mostly to evaporation during the warmer-than-usual temperatures of the past three years, a series of mild winters, and below-average snowpack in the Lake Superior basin.

Because the major factors affecting the water supply to the lakes--precipitation, evaporation and runoff--cannot be controlled or accurately predicted for more than a few weeks into the future, the influence of man-made regulation of lake levels is very limited. Nature has most of the control, adding water through snow and rain, and taking it away through evaporation.

Graphic: Lake Superior's south shore, April 2000.

Detailed Map: The Great Lakes-St. Lawrence River system


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