I’m going to have to research these some more – so beautiful! Has anyone reading this ever come across a rotating ice circle, or spinning ice disc? Or know of a scientific name for it?
Spinning ice discs are rare geometric beauties that seem to form when a river eddy catches a pan of frazil (ice needles just cold enough to stick to each other) and swirls it until it forms a perfect circle. The unfrozen eddy underneath has no reason to stop rotating, of course, so the ice circle spins as well. I’m guessing the phenom would occur within a tiny window of temperature fluctuation, since colder water would freeze solid and warmer water would not allow the frazil to cluster. Hmm. (Information about the circle near Devon available here.)
Not everyone agrees that the discs form naturally (are they the work of UFOs looking for something post-crop-circle craze? UFO Roundup and other alien-interested sites think so). The spinning circles are unusual, but not unheard of in northern countries for centuries. Here’s a shot from a Russian set of spinning ice circles.
However they’re formed, this photo of a spinning ice circle near Mississauga caused a lot of excitement in Dec. 08
Photographer Brook Tyler called the phenomenon a “creek circle” and, according to the Windsor Star, described it “as a perfectly round circle with about two inches of slush and water around the sides, and it was spinning.” Once the photos hit Digg, it got more than 150,000 views.