After years of cracking and crushing, a humorous iceberg finally broke away from the Brunt Antarctica Ice Shelf last month and began to move out to sea. Like a retrievable horizon, the event gave us a rare glimpse into the seabed that was not easy to handle and that was incredibly alive with life.
For five decades, the ocean beneath this vast piece of ice – about twice the size of Chicago – has been kept in the shadows. Now, the first rays of sunlight penetrate the depths, about 30 kilometers down (18 miles). A German search vessel that happened nearby had a front-facing seat.
For several weeks, the ice break will last Polarstern has been waiting for wind force winds and deadly waves to die until it gets around this amazing iceberg. This week, the vessel got its last chance.
The huge iceberg that separated from the Antarctic ice shelf. (NASA Universe Theater)
Despite being in darkness for half a century, the seabed has become home to a wide variety of life in a precarious landscape. Throwing a camera platform under the vessel with a long cable, researchers found many filter foods and stationery species, including sponges, anemones, sea cucumbers, starfish, soft corals, molluscs, fish, and squid.
(OFOBS-PS124 Team / Alfred Wegener Institute)
Above: A sponge of almost 30 centimeters (nearly 12 inches) in diameter attached to a small stone on the seabed.
Many of the organisms were surrounded by rocks, which would have fallen down the glaciers into the ocean.
(OFOBS-PS124 Team / Alfred Wegener Institute)
Above: Several small sponges, bryozoans, and corals encircle rocks throughout the seabed, with a worm leaving a spiral of feces in between.
The presence of filters is particularly interesting. Phytoplankton is what such creatures usually filter out of the water to eat, but these small organisms are thought to be dependent on sunlight; they are not usually found in the deep ocean.
(OFOBS-PS124 Team / Alfred Wegener Institute)
Above: Stone supports a number of filter foods. The white invitations are brittle star arms used to capture food and prey.
But perhaps in the darkness of Antarctica, they are not as rare as we thought. Or there may be organisms or other microscopic nutrients that these established creatures are filtering.
Just last month, scientists were drilling 900 meters (0.6 miles) deep into the Antarctic ice shelf above the West Weddell Sea, about 260 kilometers (162 miles) from the coast. But even here, in this amazing hollow of the sea, the team was surprised to find sponges and other filter foods also attached to stones.
“Our discovery raises so many more questions than it answers,” said biologist Huw Griffiths of the British Antarctic Survey at the time, “such as how did they get there? What do they eat? How how long have they been there? How common are they? Are these boulders covered with life? Are these the only species we see outside the ice shelf or are they species? And what would happen to those communities if the ice shelf fell? ”
The crew on board the Polarstern has already shared several sediment samples from this new seabed, as well as a once-in-a-lifetime photographic record.
(OFOBS-PS124 Team / Alfred Wegener Institute)
Above: An anemone of nearly 30 centimeters in diameter adjacent to the remains of a worm fecal tract. Dot laser for scale.
“It is very fortunate that we were able to respond flexibly and study the calf incident at the Brunt Ice Shelf in such detail,” says physicist Hartmut Hellmer at the Helmholtz Center at the Alfred Wegener Institute for Polar and Marine Research. .
“Having said that, I am even more pleased that we have replaced several moors, which continue to record basic data on temperature, salinity, and normal ocean directions and distances once we are gone . “
(Ralph Timmermann Institute / Alfred Wegener)
Above: The Polarstern crosses the smallest gap between the iceberg and the Brunt Ice Shelf, known as the “fox hole” because of its tight pressure.
The data collected from this dangerous effort will be used to better understand how the Antarctic ice sheet is tackling ongoing climate change and what we can do to help ecosystems survive. protect that price before it is too late.
“We need this knowledge to be able to take effective effects against climate change,” says Hellmer.
“The effects of climate change in Antarctica, among others, are worrying.”