One of the oddest phenomena to roll up on the shores of the Great Lakes has returned.

 

Ice balls -- frozen orbs formed in winter waves -- have again been spotted on Lake Michigan's beaches. Ken Scott, a photographer based in northern Michigan, captured images of them rolling across the beach near Suttons Bay on December 31 and posted a video to YouTube last week.

 

Scott estimated some of the ice balls were about 4 feet or 5 feet across and said the ones he saw were big enough to earn the name "ice boulders."

 

According to MLive, the boulders form when chunks break off the large sheets of ice on Lake Michigan's surface. The chunks are rounded and smoothed by waves constantly washing over them, and they grow larger as ice coats the boulders, freezing in thin layers.

 

On January 1, Scott returned to the spot where he shot video of the ice boulders, but they were gone, possibly blown up or down the shore when the wind shifted, he theorized. He said it takes "calculated luck" to see some of the amazing natural occurrences on the lake, such as last year's ice caves.