29 April 2013
"Ice needles" emerge from a Minnesota lake
Filmed at Medicine Lake in Minnesota by Nadalie, via KARE 11 News.
This is occurring during the (delayed this year) spring ice-out phase, so the ice moving ashore is different from the ice heaves that occur in midwinter when a solidly frozen ice surface expands on a warmer-than-usual winter day. Here the ice is being driven ashore presumably by prevailing winds.
The wondrous aspect of this particular event is the needle-like shape of the ice crystals. One type of needle-shaped ice is frazil ice, but I think that's different - at least in the video I bloggged some years ago of frazil ice moving at Yosemite - because frazil ice forms in supercooled water. I think what is seen here is the result of fracturing of the ice sheet.
But the video is cool. Wish I had been there to see it happen.