Watch starfish flee an icy finger of death

This clip from the BBC's Frozen Planet is one of the most amazing things you will ever see.

"Brinicle" is a clever portmanteau for an icy finger of death that forms naturally in the very cold seawater one finds around Earth's poles. A crust of sea ice can form on top of this water, and that's the first step to making a brinicle. Here's how polar oceanographer Mark Brandon explained the process in an article on the BBC website:

In winter, the air temperature above the sea ice can be below -20C, whereas the sea water is only about -1.9C. Heat flows from the warmer sea up to the very cold air, forming new ice from the bottom. The salt in this newly formed ice is concentrated and pushed into the brine channels. And because it is very cold and salty, it is denser than the water beneath.

The result is the brine sinks in a descending plume. But as this extremely cold brine leaves the sea ice, it freezes the relatively fresh seawater it comes in contact with. This forms a fragile tube of ice around the descending plume, which grows into what has been called a brinicle.

Check out that BBC website link for more information on how the Frozen Planet videographers captured this footage. That's also where you should go to watch the video when this YouTube version is inevitably taken down.

Thank you, Brittany. Truly freaking amazing.

Video Link


  1. Oh wow. This is amazing! Having just spent the afternoon in the warm mellow south Pacific Ocean, the brinacle is shockingly awesome. The BBC has captured frigid beauty.

  2. this is an awesome video.  so are the starfish actually dying?  it seems like if you can cut off one of their legs and they’ll regenerate it, maybe they can survive a little bit of freezing action.

  3. Amazing…and all the more interesting to listen to with the David Attenborough, bringing fond memories of HS science class and trying not to fall asleep.

  4. They got the description of the video a little wrong. The X-Men were out ice fishing and Bobby Drake just had to take a whiz.

  5. Personally I found the following few minutes even more astonishing – cold, deep, high-pressure water being stirred up from the depths and freezing in a layer across the sea bed as the pressure is released, encasing everything there.  Then, chunks of this break off and float up to the surface, carrying seabed wildlife up and embedding it in the underside of the surface ice.

  6. Fascinating and yet I know this is going to give me nightmares. I did not appreciate seeing starfish move at that speed, I already find underwater creatures freaky enough. I can’t help my fear :(

  7. What’s with the sound effects? I’m of the opinion that documentaries should be as close to reality as possible–adding sound effects throws the whole project into doubt. What else did they fake? 

  8. I’ve done a small amount of scuba diving in Monterey (12 dives), and even that little bit of experience makes me appreciate the mad skills that filming this required. This was cold Antarctic water, under an ice sheet, a good distance away from their entry point, and they had heavy equipment to carry.  It’s an amazing accomplishment.

  9. i was sat watching this with my dinner on my lap after getting home from work (in a science lab ironically enough). one of the few times that my jaw has just dropped and gone wha wha wha? looking at the tv.

    the mind just boggles about everything to do with it.

    obviously just the sheer fact that it even happens is mindboggling. literally a column of ice comes down (almost like  a bolt of lightning) and kills everything in it’s path.

    but then you get to thinking about the fact that it was only within the last century that human beings even managed to get to the south pole let alone make a video of what the hell happens under the sheets of ice.

    this entire phenomenon can only have ever been seen or contemplated or in any way conceived of in the very recent past. And yet it has been occurring, unobserved, for thousands and thousands of years.

    it’s almost like creatures coming out of the sea and going “what in the shitting fuck, birds fly!”

    maybe that’s hyperbolising but what the fuck, i was sat there with my dinner on my lap and my jaw on the fucking floor.

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