Brinicles are also known as an ice stalactite and they are found in both the Arctic and the Antarctic areas. That implies that in winter, the air temperature above the sea ice can below -20C whereas the sea water is about -1.9C. So, the brinicle is formed beneath the sea ice when a flow of extremely cold saline mass of water comes into an ocean warmer water.
BBC film crews recorded the brinicle as it sunk to the bottom of the sea in Antarctica.
The ‘icicle of death’ grew so rapidly towards the seabed that teams could see it advancing before their eyes. Brine falls to the surface as it is a lot more dense than seawater.
When the seawater freezes as it comes into contact with the brinicle it is a lot more spongelike than normal ice.
They are usually found in the Antarctic when saline water is introduced to the ocean.
The remarkable footage was filmed underwater in temperatures of -2C by BBC cameramen Hugh Miller and Doug Anderson at Little Razorback Island, near Antarctica’s Ross Archipelago.