Many people are used to seeing icicles hanging from tree branches, but some might now know that icicles also exist beneath the ocean. These underwater icicles, brinicles, are also referred to as “sea stalactites” because of their unique in-water formation.
Brinicles are an amazing phenomenon. However, they've also been nicknamed “icicles of death.” When brinicles sink and hit the sea floor, the perhaps unexpected happens: ice spreads across the sea floor and freezes everything it touches, including living organisms.
Brinicles were first studied in the 1960's. It's hard for scientists to learn about them, though, because they only form at certain times and under specific conditions. Scientists do know that brinicles form in the Arctic and Antarctic Oceans. This process begins when a plume of salty water, called brine, is forced out of underwater ice. The brine is much colder than the less-salty seawater, which freezes as soon as it comes in contact with the super-cooled brine. Brine is more dense then seawater, so the plume of brine sinks toward the sea floor, creating a tube of ice that grows downward.
Recently, a BBC news crew filmed brinicles. The time lapse the crew created captures a brinicle reaching the sea floor. Filmed by crewmen Hugh Miller and Doug Anderson, the time lapse captured brinicles near Antarctica's Ross Archipelago.
While the cameramen were exploring the region, they found three or four brinicles that had already touched the sea floor, and one that hadn't. The crew raced time because they didn't know when this final brinicle would touch the sea floor. The efforts they made were worth it and ultimately resulted in the first-ever video of a brinicle hitting the depths of the ocean.
There is still much to learn about this fascinating yet lethal phenomenon. Researchers continue to study these underwater icicles in hopes of learning more about them and their impact on wildlife.
[Sources: mnn.com; BBC Nature News; Frozen Planet]