Around a distant Atlantic island, a massive iceberg discharges 152 billion tonnes of fresh water

According to research published earlier this month, an iceberg that was once the world’s biggest, named A68a, recently spilled 152 billion tonnes of freshwater near the sub-Antarctic island of South Georgia, possibly affecting the region’s environment.

When A68a broke off the Larsen-C ice shelf at the Antarctic Peninsula’s tip-in 2017, it drew worldwide notice. At the time of its development, it was the world’s biggest iceberg, floating in the Weddell Sea near Antarctica before making its way through the Drake Passage between southern South America and the northernmost areas of Antarctica. Researchers were afraid that when it neared the southern Atlantic island of South Georgia in December 2020, it may upset fauna in the lonely area.

According to the new research, the massive iceberg had a significant impact on the surrounding ecology. A68a melted fast in the Drake Passage during a three-month period between 2020 and 2021 when it met warmer water. While experts originally expected that the iceberg’s keel, or the section of the iceberg under the water’s surface, might run aground on the bottom, obstructing currents and predator hunting pathways, the British Antarctic Survey reports that this does not seem to have occurred. The iceberg’s massive pulse of freshwater, however, is likely to have had an influence on the South Georgia environment.

The next step, according to Anne Braakmann-Folgmann, the study’s primary author, is to figure out precisely what that influence looked like. A68a’s passage via the Drake Passage, according to Braakmann-Folgmann, might help researchers learn more about future icebergs and “how they impact the northern waters.”

Given that climate change is anticipated to hasten ice shelf collapse, resulting in more large icebergs breaking off Antarctica in the future, this knowledge will be invaluable.