Scientists Confirm Existence of 40 Huge Craters at the Bottom of Lake Michigan

The Great Lake Craters

Researchers have recently confirmed the existence of sizable craters at the bottom of Lake Michigan, further deepening the mystery of these unexplained underwater formations. An area famous for its vast collection of 36 known shipwrecks, the lake’s deep bed reveals findings that have aroused the curiosity of researchers globally.

Experts studying the lakebed of the Wisconsin Shipwreck Coast National Marine Sanctuary initially spotted the bemusing circles during a mapping mission back in 2022, leaving them puzzled for the two following years. New comprehensive observations of the lake have since confirmed that these circles are indeed craters with further secrets to unravel. These remarkable findings serve as a reminder of the mysteries that lie beneath the seemingly familiar surfaces of our planet.

The Investigation

The peculiar formations were noticed by Russ Green, a maritime archaeologist and superintendent of the sanctuary, and his colleagues as they embarked on surveying the lakebed. The circles, deemed to be natural rather than man-made, suggested depressions in the bed, but required more research for a definitive conclusion.

However, it was not until local shipwreck hunter Brendon Baillod discovered the same enigmas during his own search for a sunken freighter that their actual depth was recognized. Baillod expressed that the craters measured between 20 and 40 feet (6 to 12 meters) deep. “There were dozens of them in our search grid,” he confirmed. “Most were 500 to 1,000 feet [150 to 300 m] in diameter and of irregular shapes.”

A joint effort between the original surveyors and scientists from the National Oceanic and Atmospheric Administration’s (NOAA) Great Lakes Environmental Research Laboratory (GLERL) led to the launch of a comprehensive survey in 2024. Their method, using a remotely operated vehicle, confirmed that the obscure circles are large, naturally-occurring craters.

Nature Does It Again

The evident group of approximately 40 craters is likely to grow, as there may be more yet to be discovered, says Steve Ruberg, a researcher at GLERL. Their formation is similar to sinkholes, caverns created by the dissolution of bedrock from below due to groundwater, which causes the surface layer to collapse. This teasing hypothesis is backed by the fact that part of Lake Michigan rests on limestone, a rock prone to dissolution.

Not all researchers are fully convinced that the craters are sinkholes, warning against labelling them without further investigation. Supporting this viewpoint, Brendon Baillod refers to them as craters instead, suggesting that they could have been formed due to upwellings of water from below or trapped hydrocarbon off-gasing.

Further curiosity is ignited by the lack of escaping water from the craters, which would commonly indicate groundwater circulation beneath the lakebed. Regardless, Ruberg predicts that this evidence may only be a matter of time. Besides, the craters are already proving to be important habitats for freshwater shrimp, small fish, and invasive quagga mussels, further highlighting their biodiversity value and role in the lake’s ecosystem.

The Mystery Persists

Regardless of the uncertainty surrounding their origin and the extent of their ecological impact, researchers are undaunted. The collective imagery and curiosity provoked by these underwater phenomena serve as a reminder of the enigmas that lie below the water’s surface. Further exploration and research will reveal more about these peculiar landmarks located in the deepest recesses of Lake Michigan. “We’ll be exploring them for years to come to learn more, and sort out how they got there and what role they play in Lake Michigan’s ecosystem,” claims Russ Green.