As of Thursday, ice cover extended across 88 percent the Great Lakes according to the federal government's Great Lakes Environmental Research Laboratory in Ann Arbor, the Associated Press reported.
"That arctic vortex came down, and the ice just kept going," said George Leshkevich, a physical scientist with the federal lab, the AP reported.
Sections of the lakes, which hold nearly one-fifth of the freshwater on the world's surface, harden almost every winter, according to the AP. That freezing keeps the Coast Guard's fleet of nine icebreakers busy clearing paths for vessels hauling essential cargo such as heating oil, salt and coal.
In the past four decades, the average ice cover has receded 70 percent, scientists say, probably in part because of climate change, the AP reported.
Buffalo, N.Y, got nearly 43 inches of snow in January, but this month just 13 inches have fallen, a decline resulting largely from the freeze-over of Lake Erie even though Lake Ontario has remained largely open, said forecaster Jon Hitchcock of the National Weather Service, according to the AP.
At Apostle Islands National Lakeshore in Wisconsin, the rock-solid cover has allowed around 35,000 visitors to trudge miles over Lake Superior to explore caves featuring dazzling ice formations, the AP reported It's the first time in five years the lake surface has been firm enough to allow passage.
"Seeing them like this is almost a once-in-a-lifetime experience," Superintendent Bob Krumenaker told the AP.
There's even an (apparently) tongue-in-cheek Facebook page inviting people to join a convoy of snowmobiles, cars and other vehicles on a nearly 80-mile trek across Lake Michigan though its waters remain partly open and experts warn the ice can be dangerously unstable, the AP reported.
"If it freezes, and you miss this chance, when will it happen again?" the page says, according to the AP. "Feel free to invite more folks!"
