According to LiveScience, scientists used sonar equipment to locate approximately 40 strange craters beneath Lake Michigan. These remarkable formations, extending between 500 and 1,000 feet in diameter, were discovered during a survey of the Wisconsin Shipwreck Coast National Marine Sanctuary. The craters, which are southeast of Sheboygan, Wisconsin, were confirmed in August 2024 by researchers from NOAA’s Great Lakes Environmental Research Laboratory (GLERL) and maritime archaeologist Russell Green.
Local shipwreck hunter Brendon Baillod first noticed the depressions while looking for a sunken vessel. He described them as irregularly shaped and 20 to 40 feet deep and said they could be generated by trapped gas or water upwelling. Kevin Cullen of the Wisconsin Maritime Museum argued that the craters could be linked to old underwater gorges caused by glaciers or sinkholes, given Lake Michigan’s partly limestone formation. However, no groundwater movement has been recorded in the craters thus far.
According to GLERL’s Steve Ruberg, further research may yet reveal water circulation beneath the lakebed. Freshwater prawns, tiny fish and invasive quagga mussels have all been identified in the craters. The craters remain a geological enigma, with researchers planning additional investigations to better understand their creation and influence on Lake Michigan’s ecosystems.
