Source: Journal of Geophysical Research: Oceans
Ice shelves surrounding Antarctica have been melting with increasing speed in recent years. Much of this melting happens from below, as warm water eats away at their bases. This warm water is moved around Antarctica by currents that remain only partially understood because of the continent’s vastness and remoteness. Mapping these currents in better detail will improve understanding of the future of the continent’s mantle of ice.
The 2013 Marine Mammals Exploring the Oceans Pole to Pole (MEOP) database relied on seals to carry temperature and salinity sensors into remote regions of West Antarctica’s Bellingshausen Sea. Flexas et al. combined data from this initiative with 2020 data from an autonomous undersea glider to take a better look at the hydrographic properties of the region, including temperature, salinity, and dissolved oxygen levels.
They learned that meltwater flowing out of the Bellingshausen Sea—a relatively understudied body of water west of the Antarctic Peninsula—has a strong effect on ice shelves throughout West Antarctica. They also uncovered a seafloor trough they named Seal Trough for the instrument-laden pinnipeds that helped discover it.
The researchers found two distinct sources of meltwater moving through the sea, one from the Venable Ice Shelf flowing through Belgica Trough and the other from the Abbot Ice Shelf farther west flowing through Seal Trough. Both flows contribute to the Antarctic Coastal Current (AACC) and may also affect ice shelves in other regions of Antarctica. Data also indicated that both the Bellingshausen Sea and the AACC extend farther west than previously realized, with the sea extending to Seal Trough and the AACC reaching into the Amundsen Sea.
Future work should more deeply probe the contributions of ice shelf water to the Bellingshausen Sea, the authors say, and should be updated with synchronous data on water flows, given the 7-year disparity between their current data sets. (Journal of Geophysical Research: Oceans, https://doi.org/10.1029/2023JC020080, 2024)
—Nathaniel Scharping (@nathanielscharp), Science Writer