(click title above to watch video and read about the logistics going into filming it)
I’d heard about these but never could find a video of one… Leave it to BBC Nature’s cameramen and specialists to finally record a time-lapse video of a brinicle (seawater icicle) forming and wreaking havoc on the poor unsuspecting sea stars and sea urchins below. The brinicle forms as hypersaline (super-salty) water sinks, and the water that is slightly less salty freezes at the hypersaline/slightly-less-hypersaline boundary. Worth the 1.5 minute watch - one of the best time-lapse videos I’ve seen, bar none.
Image below is of the filming setup for the time-lapse video, from BBC Nature (http://news.bbcimg.co.uk/media/images/56860000/jpg/_56860983_hughmillertimelapsebrinacle-4.jpg):