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U-M divers retrieve 8,900-year-old piece of wood from Lake Huron
Annarbor.com (12/12)
University of Michigan researchers announced they have found a 5 1/2 foot long, pole-shaped piece of wood that is 8,900 years old in Lake Huron.
Internationally renowned ‘Ocean Doctor’ to speak in Grand Rapids
MLive.com (2/3)
Known as the “Ocean Doctor,” David Guggenheim will speak in Grand Rapids, Mich., about the many similarities between the threats to the oceans and to our Great Lakes.
SSC students taking part in marine science bowl
Arenac County Independent (1/31)
Teams of Michigan high school students will be heading to Ann Arbor this weekend to take part in the annual Great Lakes Bowl, a quiz event that focuses on questions about marine and freshwater systems and biology.
No aquarium for Windsor
CBC News (1/31)
Aquariums in Cleveland, Toledo, and Chicago prove to be too much competition for Windsor.
Clarkson receives $1.4 million to study contaminants in Great Lakes fish
North Country Now (1/31)
Clarkson University has received $1.4 million to monitor formerly untraceable contaminants to water supply by studying the effects on fish in each of the Great Lakes.
Great Lakes scientists educate communities; put research to work
Great Lakes Echo (1/26)
At the Lake Superior Estuarine Research Reserve, scientists study the usual Great Lakes issues – invasive species, pollution, habitat loss, and climate change. This research is then taken directly to the community, addressing local issues.
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.
4 | How levels and flows are measured
Water levels are measured and recorded at many locations around the Great Lakes and on their connecting channels.
The National Ocean Service of the National Oceanic and Atmospheric Administration (NOAA) presently operates 31 water level gages on the Great Lakes and 18 gages on the connecting channels. In Canada, the Canadian Hydrographic Service maintains 29 water level gages on the Great Lakes and 27 on the St. Lawrence River. Other agencies, including the U.S. Army Corps of Engineers, New York Power Authority and Ontario Power Generation, also operate recording gages at various locations on the lakes.
See also: Map of Great Lakes Water Level Gauging Stations
Great Lakes water levels are officially measured from the International Great Lakes Datum 1985 (IGLD 1985). This datum is referenced to sea level, as measured at Rimouski, Quebec, near the mouth of the St. Lawrence River. Because the crust of the earth in the Great Lakes region is continuously rising with respect to sea level, and the rate of movement is not uniform throughout the region, the IGLD must be updated every 25 to 30 years.
See also: FAQ about the International Great Lakes Datum
The rate of flow, or discharge, in a river or Great Lakes connecting channel is determined by measuring the channel depth and width, and the velocity of the flow. Measurements can be made by boat, from a bridge, or from a cableway strung across the river. With sufficient measurements of flow over a range of water levels, mathematical relationships can be developed between levels and discharges for various points along the connecting channels and the St. Lawrence River. These equations are essential to the coordination of outflow data, particularly related to hydroelectric power usage of Great Lakes waters.
Graphics: Water level gaging station; measuring outflows at the Niagara Cableway.
