Islamabad, Dec 19: The world’s largest iceberg, A23a, is once again drifting through the Southern Ocean after months of being stuck in the same location, according to scientists from the British Antarctic Survey (BAS).
Covering an area of 3,672 square kilometers (1,418 square miles) as of August—slightly larger than Rhode Island—the A23a iceberg has been closely monitored since it broke away from the Filchner-Ronne ice shelf in 1986. For over 30 years, it remained grounded on the seafloor of the Antarctic’s Weddell Sea, likely until its size decreased enough to free it. It then moved with ocean currents before getting caught in a Taylor column—a spinning water vortex caused by currents interacting with an underwater mountain.
Having now escaped this vortex, the iceberg is expected to continue drifting toward warmer waters and the remote island of South Georgia, where it will likely disintegrate and melt, BAS stated. Since the 1980s, A23a has repeatedly held the title of the “largest current iceberg,” sometimes surpassed by larger but short-lived icebergs like A68 in 2017 and A76 in 2021.
While A23a’s calving was likely part of the natural ice shelf growth cycle and won’t contribute to sea level rise, scientists warn that climate change is significantly altering Antarctica, posing serious risks for global sea levels.
Researchers have studied the iceberg’s erosion and its influence on global ocean carbon and nutrient cycles during its journey. Laura Taylor, a BAS biogeochemist, highlighted that massive icebergs can enrich the waters they pass through, fostering ecosystems in otherwise low-productivity regions.
Taylor and her team collected water samples from different areas around the iceberg to better understand the impact of A23a’s presence on ocean life and the carbon balance between the ocean and atmosphere.
