Analyzing channel currents near the Marquette Lake Superior shoreline

Studying dangerous currents with new technologies may save more lives as science helps forecast when and where these currents form.

Michigan State University Extension, Michigan Sea Grant, Michigan Department of Environmental Quality and the National Weather Service coordinated a series of Dangerous Currents Workshops in three different locations in Michigan in June. The workshops helped increase knowledge about dangerous currents by educating local, state and federal parks personnel, emergency responders, volunteers, researchers, educators and others about Great Lakes beach hazards.

Keith Cooley, with the National Weather Service, presented findings from an analysis of channel currents along the Lake Superior shoreline at Picnic Rocks in Marquette, where 15 lives have been lost since 1963. Channel currents in this area move parallel to the shore and are caused by the squeezing of water between the shore and Picnic Rocks. This action causes the current to speed up in this area. Channel currents can also be found at Hogs and Washington Islands in Lake Michigan, Saddlebag Island in Lake Huron, and at Presque Isle in Lake Erie.

Two years ago, Michigan Sea Grant assisted the City of Marquette in obtaining a grant through the Great Lakes Observing System to secure an acoustical Doppler current meter. This meter was placed in the water at Picnic Rocks and since then, Cooley has been analyzing the data from the meter since its deployment.

Some of the results, thus far, indicate that channel currents occur when the winds are blowing from the north, northwest, and the south directions. Waves with a northerly or southerly component tend to cause hazardous current speeds, especially when the wave heights are 2 to 5 feet. Future analysis of these channel currents will continue throughout this summer in hopes of developing a predictive model to forecast these currents.

The Michigan Coastal Zone Management Program – MDEQ, provided financial assistance for these workshops through a grant from the National Oceanic and Atmospheric Administration, and U.S. Department of Commerce. The Michigan Coastal Zone Management Program partners with local governments, non-profit organizations and universities to promote wise management and prudent use of the cultural and natural resources within our coastal boundary.

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