'Lake Michigan marbles' -- ice boulders that have people talking

Lake Michigan makes marbles.

As pictures of beach-ball-sized ice boulders went viral this week, the visitor center at Michigan's Sleeping Bear National Lakeshore got swamped.

"They've gotten a lot of phone calls," the park's chief of interpretation and visitor services, Lisa Myers, told the Los Angeles Times. "It's really spectacular."

Although this year’s "Lake Michigan marbles" are much bigger than usual, Myers said they're not a new phenomenon.

Ice chunks form along the shore, get churned back and forth by the waves and grow slowly in the just-below-freezing water, which also helps to smooth the boulders, she said.

[link to www.latimes.com]