• Question: Is it possible for there to be a part of the ocean, so far below, that it is supercooled?

    Asked by to Ben, Emily, Hattie, Jemma, Veronica on 24 Jun 2014. This question was also asked by .
    • Photo: Ben Butler

      Ben Butler answered on 24 Jun 2014:

      Great question muizzasif2000!

      Supercooling is really interesting, it basically means cooling something below it’s freezing point without it freezing! In order to supercool water, it has to be REALLY pure, and by that I mean there can’t be any particles of dust, sediments, or anything else that could act as a place where the ice can start growing from. If you had a bottle of PERFECTLY pure water (which is impossible to get), then technically it would never freeze because there would be no particles for the ice to start growing on.

      The ocean usually has lots of tiny particles floating around all over the place, so it’s pretty tricky to supercool seawater.

      Having said that, the freezing point of seawater does get lower as pressure is increased… so the deeper you go in the sea, the colder the seawater has to get before it freezes. Because of this, water in the reeeally deep sea can be colder than -2 degrees, but this isn’t technically ‘supercooled’.

    • Photo: Emily Hayward

      Emily Hayward answered on 24 Jun 2014:

      Hi Muizzasif2000,

      What a great question! To be supercooled liuids need to be extremely pure, whereas in the ocean there are lots of particles and a lot of salt preventing the water being supercooled. The addition of salt to water makes it behave differently and it cen still be a liquid below 0 degrees though! At the bottom of the ocean in places (especially where its deep and the pressure is large) the temperature is below freezing yet the sea is still a liquid. A fun experiment to do is when its snowy you can put some salt on the snow and it melts (this is why they put salt on the roads in winter) because the salt changes the freezing point of water – pretty cool eh?

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