RISE UP/GEAR UP

The science behind the spinning ice circle

This is likely how that ‘utterly gorgeous’ spinning ice circle formed…

The ice circle might have been formed by a “corkscrew motion” caused by melting ice and a slow current. An ice circle that formed over the weekend in the Middle Fork Snoqualmie river was a curiosity not only to those who photographed it, but to scientists fascinated by the phenomenon.

“They’re super weird, super cool and utterly gorgeous,” David Montgomery, a University of Washington Professor of Geomorphology. “I’ve never seen one in real life, and I study rivers.”

Montgomery said there are two ways he believes the ice circle could have formed.
Sometimes, he said, ice circles form at bends of a river as eddies push floating ice against a spin at the river’s bank, Montgomery said. But they have formed on straight stretches of water, too.

Montgomery thinks that is likely due to a corkscrew-like force on the ice, which is caused by melting ice and the current.

See photos and read full article in The Seattle Times.