The A23a iceberg is four times the size of New York City. It broke from the Antarctic coastline in the 1980s but got stuck to the floor of the Weddell Sea. There it stayed until 2020, when it freed itself and began drifting. Now, the "megaberg is in its spinning era," said the British Antarctic Survey on X. A23a entered the Antarctic Circumpolar Current (ACC), which would normally cause the berg to move faster. However, it has instead got caught up in a Taylor column, a type of vortex.
"It's basically just sitting there, spinning around, and it will very slowly melt as long as it stays there," Alex Brearley, the head of the Open Oceans research group at the British Antarctic Survey, told The New York Times. While A23a breaking off into the sea is not necessarily a concern, the Antarctic is seeing the effects of climate change, and that is worrisome. The "increasing rate of iceberg calving in Antarctica raises concerns about the stability of ice shelves and the potential for accelerated sea-level rise," said Earth.com.
Icebergs can also greatly affect marine ecosystems, serving both as creator and destroyer. An iceberg like A23a can shed nutrients it "accumulated from Antarctica" and stir up "deep water, possibly sparking a plankton bloom in its wake," NPR said, and such an iceberg can also "scrape and scour the seafloor in shallow waters," wrecking the ecosystem. |