Canyons under the Antarctic have deep impacts

Beneath Antarctica's vast expanse of ice sit hundreds of canyons, some up to tens of thousands of feet deep. These complex formations under a seemingly barren landscape play a significant role in global climate change and ocean circulation — and studying them could lead to better climate models and predictions.

Rolling in the deep

Scientists have mapped 332 underwater canyons in Antarctica, according to a research article published in the journal Marine Geology. Some of these are deeper than 4,000 meters (over 13,000 feet). Antarctic submarine canyons "resemble canyons in other parts of the world," David Amblàs, a part of the Consolidated Research Group on Marine Geosciences at the University of Barcelona and one of the authors of the article, said in a statement. "But they tend to be larger and deeper because of the prolonged action of polar ice and the immense volumes of sediment transported by glaciers to the continental shelf."

The canyons also vary significantly between east and west Antarctica. In the east, the canyons are "intricate and branching, with wide U-shaped profiles," while the western canyons "are shorter and steeper, cut into sharp V-shapes," said IFL Science. These findings indicate that the East Antarctic Ice Sheet is likely much older than its western counterpart. "This had been suggested by sedimentary record studies," Amblàs said, "but it hadn't yet been described in large-scale seafloor geomorphology."

The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

SUBSCRIBE & SAVE

Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up

Scientists posit that the canyons "may have a more significant impact than previously thought on ocean circulation, ice-shelf thinning and global climate change, especially in vulnerable areas such as the Amundsen Sea and parts of East Antarctica," said the statement.

Zone of interest

Submarine canyons are "vitally important to ecological, oceanographic and geological processes worldwide," said Discover. The canyons "facilitate water exchange between the deep ocean and the continental shelf, allowing cold, dense water formed near ice shelves to flow into the deep ocean and form what is known as Antarctic Bottom Water," said the University of Barcelona statement. They also do the reverse, where they transport "warmer ocean waters from the sea toward the coastline," which helps "maintain and stabilize Antarctica's interior glaciers," said Discover.

The role of submarine canyons is thus far a "blind spot in climate change science," said Discover. There is not much known about the deep-sea gorges because less than one-third of the seafloor has been properly mapped. "Since so many submarine canyons are undiscovered and understudied, they do not factor into many of the current climate change models," the outlet added. This may be understating their effect on climate change. "Omitting these water-transporting canyons drastically limits the ability of climate change models to accurately predict ocean and overall climate changes."

Scientists have identified approximately 10,000 submarine canyons globally, but most remain unexplored, particularly those in polar regions. "Mapping the seafloor and its influence on the movement of water is necessary to build accurate ocean circulation models," said The Guardian.