When salt-rich water leaks out of sea ice, it sinks into the sea and can occasionally create an eerie finger of ice called a brinicle. New research explains how these strange fingers of ice form and how the salty water within sea ice could have been aprime environment in which life may have evolved.
These ice stalactites are created under sea ice when cold, saline water is introduced to an area of ocean water. At the time of its creation, a brinicle resembles a pipe of ice reaching down from the underside of a layer of sea ice.
As the sea water freezes, it pushes out impurities, including salt. This makes the water surrounding the pipe more saline, and more dense, so it starts to sink. As the dense water flows down, some of it freezes and creates the finger-like shape that’s characteristic of the brinicle.
At first, a brinicle is very fragile; its walls are thin and it is largely the constant flow of colder brine that sustains its growth and hinders its melt that would be caused by the contact with the less cold surrounding water.
Check out the source for an awesome video of this process!