Via some breathtaking footage, we are able to witness the construction of a “ice finger of death” for the first time ever.
These days, finding phenomena that are entirely novel to science and that enhance our understanding of the universe in fascinating and novel ways is rare. But recently, the formation of Antarctic brinicles, sometimes known as “ice fingers of death,” was revealed to armchair explorers in the form of some magnificent footage, much as it did in the previous several years with uncontacted tribes, unknown tunnels, and sea creatures.
Strange, finger-like structures called brinicles extend downward from the floating sea ice into the chilly Antarctic waters. Even though they have been recognized by scientists since the 1960s, they are rarely seen in action. Ice fingers are extremely difficult to monitor and nearly impossible to photograph since they only appear under precise conditions in the polar regions of Earth. This is what makes the below clip from Season 1 of Series 5 of BBC’s Frozen Planet so unique.
The ice on the ocean’s surface is made up of two elements, unlike frozen freshwater. The majority of the salt is removed from the water during freezing, leaving the ice crystal itself relatively pure. However this results in too much salt being present. The remaining salty water does not freeze because it requires considerably lower temperatures to do so, causing channels of extremely saline brine to form inside the porous ice block.
As the sea ice that is floating breaks, saline water solution pours out into the open ocean below, creating a brinicle. The brine freezes the comparatively fresh water it comes into contact with because it is heavier than the water around it and sinks to the ocean floor. This procedure permits the brinicle to grow downward, giving it the appearance of a finger.
One of the few scientists, Dr. Andrew Thurber, who has personally witnessed brinicle growing, describes a fantasy scene that is punctuated by downward creeping brinicles. He remarks, “These appear to be blown glass upside-down cacti, like something from Dr. Suess’s imagination. They are exceedingly fragile and easily break with the smallest pressure.
Thousands of brinicles, many of which extend to the bottom, live in this 3 m-deep region of Little Razor Back Island in Antarctica. Thousands of amphipods, which are seen swimming in this picture, live among them. The amphipods swarm when startled, like a beehive despite only being found near to the ice in their natural habitat.
The flimsy ice sheaths, however, conceal a lethal weapon for the adjacent marine life: as seen in the video, a brinicle can reach the seafloor and, as it spreads from there, it may eventually grab and freeze other organisms living there, such sea urchins and starfish.
“In areas that used to have the brinicles or underneath very active ones, small pools of brine form that we refer to as black pools of death,” Thurber notes. “They can be quite clear but have the skeletons of many marine animals that have haphazardly wandered into them.”