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After causing Hell to freeze over and stopping Niagara Falls in its tracks , the polar vortex gripping the US has led to another incredible natural phenomena - floating ice boulders.
The sub zero temperatures have brought huge, nuclear snowballs to the shores of Lake Michigan.
The incredible basketball sized - and bigger - 'ice balls' have been captured on film at Glen Arbor Township, Michigan, were they cover the entire shoreline.
Despite appearing as unnatural creations, the boulders are a regular feature of Lake Michigan when temperatures drop below freezing, and are formed by ice clumping together in a similar way to snowballs.
Meteorologist Joe Charlevoix explains: "[When] the water temperature on the Lake Michigan is just a little bit below freezing, so you get a small piece of ice that forms in the water and as waves move back and forth it adds additional water and freezes in layers.
"It gets bigger and bigger, and eventually you get big balls of ice, that are pushed to the shore by the wind."
Some locals have an alternative explanation however: "The creature that dwells within Lake Michigan lays eggs once every 10,000 (or so) years. Evacuate now while you still can!" joked Les Lukacs on the Glen Arbor Facebook page.
Polar vortex in pictures: Best photos of American 'big freeze'Show all 38 1 /38Polar vortex in pictures: Best photos of American 'big freeze' Polar vortex in pictures: Best photos of American 'big freeze' USA Sunlight streams through the windows of the Waterman Opera House, Nebraska
Polar vortex in pictures: Best photos of American 'big freeze' USA A city bench and other structures are covered in a thick layer of ice in Plattsmouth, Nebraska
Polar vortex in pictures: Best photos of American 'big freeze' USA Frozen water clings to the Grand Haven South Pier in Grand Haven, Michigan
Polar vortex in pictures: Best photos of American 'big freeze' USA Cold weather lingered in Michigan as many students returned to school for the first time this year, and roads were slippery with freezing rain and snow in the forecast that could cause more problems
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice covers the lights along the Grand Haven South Pier in Grand Haven, Michigan
Polar vortex in pictures: Best photos of American 'big freeze' USA An aerial view of the city of Chicago
Polar vortex in pictures: Best photos of American 'big freeze' USA Many visitors gathered to observe the falls in Niagara Falls, Ontario
Polar vortex in pictures: Best photos of American 'big freeze' USA The frozen mist from Niagara Falls coats the landscape around Prospect Point at Niagara Falls State Park making it a study in white
Polar vortex in pictures: Best photos of American 'big freeze' USA The US side of the Niagara Falls pictured in Ontario
Polar vortex in pictures: Best photos of American 'big freeze' USA The frigid air and 'polar vortex' that affected about 240 million people in the United States and southern Canada will depart during the second half of this week, and a far-reaching January thaw will begin
Polar vortex in pictures: Best photos of American 'big freeze' USA Prospect Point at Niagara Falls State Park in Ontario
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice chunks and water flow over the falls Niagara Falls, Ontario
Polar vortex in pictures: Best photos of American 'big freeze' USA The Chicago skyline is framed by icicles in Chicago, Illinois
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice forms on parts of a dock on West Grand Traverse Bay near the Great Lakes Maritime Academy in Traverse City, Michigan
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice covers power lines and after a high pressure water main broke in the sub-freezing winter weather in Dunwoody, Georgia
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice covers power lines and the street after a high pressure water main broke in the sub-freezing winter weather in Dunwoody, Georgia
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice builds up along Lake Michigan at North Avenue Beach in Chicago, Illinois
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice in the Mississippi River flows past the Gateway Arch in St. Louis
AP
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice builds up along Lake Michigan as temperatures dipped well below zero in Chicago
Polar vortex in pictures: Best photos of American 'big freeze' USA Chicago hit a record low of -16 degree Fahrenheit this morning as a polar air mass brought the coldest temperatures in about two decades into the city
Polar vortex in pictures: Best photos of American 'big freeze' USA The Chicago skyline is seen behind a large chunk of ice near North Avenue Beach
Polar vortex in pictures: Best photos of American 'big freeze' USA A beach front is covered in ice in Chicago, Illinois
Polar vortex in pictures: Best photos of American 'big freeze' USA A deadly blast of arctic air shattered decades-old temperature records as it enveloped the eastern United States
Polar vortex in pictures: Best photos of American 'big freeze' USA Homes are seen covered in snow and ice in Chicago
Polar vortex in pictures: Best photos of American 'big freeze' USA The Chicago skyline and a freezing Lake Michigan are seen from the Museum Campus in Chicago
Polar vortex in pictures: Best photos of American 'big freeze' USA A snow encrusted bicycle with wind chills nearing minus 30 Fahrenheit in downtown Chicago
Polar vortex in pictures: Best photos of American 'big freeze' USA A car partially covered in ice in Baltimore, where temperatures continue to remain well below freezing
Polar vortex in pictures: Best photos of American 'big freeze' USA The frozen shore of Lake Superior
Polar vortex in pictures: Best photos of American 'big freeze' USA A man prepares to remove his plow stuck in a snow bank as snow and wind swirls in St. Louis
Polar vortex in pictures: Best photos of American 'big freeze' USA Four homeless men warm themselves on a steam grate by the Federal Trade Commission, blocks from the Capitol, during frigid temperatures in Washington. A winter storm that swept across the Midwest this week blew through the Northeast, leaving bone-chilling cold in its wake
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice from the breath of Gail Davis forms around her face as she exercises by walking outside in Minneapolis
Polar vortex in pictures: Best photos of American 'big freeze' USA A man wears a face mask and heavy clothes while walking through downtown Springfield, in blowing and falling snow as a strong winter storm moves through the Midwest. Temperatures not seen in years are likely to set records in the coming days across the Midwest, Northeast and South, creating dangerous travel conditions and prompting church and school closures
Polar vortex in pictures: Best photos of American 'big freeze' USA Allan Umscheid, owner of Yards By Al in Lawrence feels the bitter wind and catches drifting snow on his face as he runs a snow blower
Polar vortex in pictures: Best photos of American 'big freeze' USA An exterior waterfall that froze overnight is seen at the National Museum of the American Indian in Washington
Polar vortex in pictures: Best photos of American 'big freeze' USA Ice forms on the shore of the East River due to unusually low temperatures caused by a polar vortex in New York
Polar vortex in pictures: Best photos of American 'big freeze' USA Dogs on a surface of frozen swimming pool
Polar vortex in pictures: Best photos of American 'big freeze' USA Snow covers an Abraham Lincoln statue in Hackley Park in Muskegon, Michigan
Polar vortex in pictures: Best photos of American 'big freeze' USA St. Simon's on the Sound Episcopal Church's fountains is frozen over in Fort Walton Beach, Florida
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