"Frazil ice" at Yosemite

In Minnesota we would call this "slush."  The rangers at Yosemite refer to it as "frazil ice," which seems a little different from the definitions I've read, which require supercooled water.  Whatever... we'll concede the word, because the behavior of the ice is so ... can we say "cool?"

Via Boing Boing and the Upcoming Queue.