CHICAGO (AP) — Geologists in Illinois are launching a helicopter survey of sand in Lake Michigan in the Chicago area.

Beginning as early as Wednesday, a low-flying helicopter will haul what appears to be a giant, mechanical Hula-Hoop carrying a large electromagnetic array. The helicopter will be used from Kenosha to the Illinois-Indiana state line, the Chicago Tribune (http://trib.in/2mMDomY ) reported.

The Illinois State Geological Survey hopes to figure out where the lake's sand has gone.

"In some areas, there's not enough sand and, in other places, there's too much," said Diane Tecic, program director of the Illinois Department of Natural Resources' Coastal Management Program. "What we realized is we don't have all the information that we need to make decisions and find actual solutions that are going to work (to fix this issue)."

Equipment on the helicopter will diagram the landscape of the lake floor by using electromagnetic signals. Researchers will be able to get a clearer picture of the lake's profile and better understand its composition.

"That's a really important baseline," state geologist Ethan Theuerkauf said. "This particular technology will tell you not only where sand is, but the thickness of those deposits."

Over the past 200 years, man-made infrastructure such as piers and harbors has disrupted the natural, southward drift of sand from Wisconsin to Indiana, the process that formed the Indiana Dunes over thousands of years.

A survey conducted last year by the Alliance for the Great Lakes, a Chicago-based nonprofit, found that the issue has cost coastal communities in Illinois roughly $3 million a year as they dredge harbors and import sand for beaches.

"We need to work on understanding our coastline," Tecic said. "We have really important recreational assets, natural habitats and economics along Lake Michigan. And all of that is threatened by the way the sand is moving."

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Information from: Chicago Tribune, http://www.chicagotribune.com