Mystery of dozens of giant circular structures at the bottom of Lake Michigan

The Great Lakes Environmental Laboratory (GLERL) of the National Oceanic and Atmospheric Administration (NOAA) has confirmed the existence of about 40 mysterious circular structures at the bottom of Lake Michigan in the US.

In 2022, NOAA experts were surveying the Great Lakes using sonar when they discovered circular structures on the bottom of Lake Michigan. These structures ranged in size from 91 to 183 meters, according to IFL Science on October 1.

NOAA survey ship and image of some calderas at the bottom of Lake Michigan. (Photo: noaa).

During a survey conducted in August, a NOAA team traveled to an area about 14 miles (22.5 kilometers) from Sheboygan, Wisconsin, to study and counted about 40 circular objects.

'A geological question arises: How did the structures form? Why are they there, especially embedded in the bedrock of the lake floor?' asks Wisconsin Maritime Museum Director Kevin Cullen.

Mr Cullen theorizes that these sinkholes are linked to underwater canyons formed by glaciers centuries ago.

However, Wisconsin shipwreck hunter Brendon Baillod suggests they may not be sinkholes, but rather calderas .

More research is needed in the future before it can be determined what the circles really are.