Beneath Lake Michigan, Around 40 Strange And Circular Structures Can Be Found

In recent years, the National Oceanic and Atmospheric Administration’s (NOAA) Great Lakes Environmental Research Laboratory (GLERL) has discovered around 40 circular structures at the bottom of Lake Michigan.
In 2022, researchers at NOAA were surveying the Great Lake when they spotted strange circular depressions in the lakebed using sonar. The depressions, ranging from 91 meters (300 feet) to 183 meters (600 feet) across, caught the attention of a shipwreck hunter at about the same time, though scientists only recently had a chance to get a better look at them.
Undertaking an expedition in August 2024, the team found around 40 of the marks, presumed to be sinkholes, around 22.5 kilometers (14 miles) southeast of Sheboygan stretching in a line towards Port Washington.
“There were dozens of them in our search grid,” Brendon Baillod, the shipwreck hunter who saw them in 2022, told Live Science. “Most were 500 to 1,000 feet [152 to 309 meters] in diameter and of irregular shapes.”
The sinkholes likely formed through usual geological processes.