Fantastic footage of an icy finger of water in timelapse mode
Another marvel of timelapse footage this month shows the Brinicle, aka an icy finger of death filmed in the Antarctic by Hugh Miller and Doug Anderson beneath the ice off the foothills of the volcano Mount Erebus, in water as cold as -2C. It was aired by the BBC recently as part of their ‘Frozen Planet’ series.
Polar oceanographer Dr Mark Brandon explained this unusual phenomenon: “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.”
As you can see on the video, where the brinicle touches the sea bed, a web of ice forms that freezes everything it touches instantly, including sea urchins and starfish.
Credit to Baul for alerting us to this feature
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