The world’s largest iceberg, A23a, might be moving towards the British territory of South Georgia. CNN
The world’s largest iceberg, named A23a, continues to drift across the Southern Ocean, causing growing concerns that it might soon collide with the island of South Georgia, a British Overseas Territory in the South Atlantic. This massive iceberg has been monitored by scientists ever since it calved, or broke away, from the Filchner-Ronne ice shelf in Antarctica in 1986.
Initially, A23a became trapped around an underwater mountain, where it rotated for several months before it was freed by ocean currents. According to Andrew Meijers, a physical oceanographer at the British Antarctic Survey, the iceberg is currently moving toward South Georgia, although it is not directly headed for the island yet. "It is presently in a meander of the current and not moving directly towards the island," Meijers explained. However, he added that predictions suggest it could soon head in the direction of South Georgia.
If A23a maintains its current structure, it can be easily tracked, but the real concern is that the iceberg might break apart into smaller chunks, which would be much harder to monitor and could pose a significant threat. Simon Wallace, a sea captain from the South Georgia government vessel Pharos, expressed concern over this possibility, saying that smaller icebergs are harder to spot and could cause serious problems. "All ice is very dangerous. The bigger it is, the easier it is to find and avoid. Smaller ice is much harder to detect but by no means less hazardous," he said. These smaller icebergs could disrupt local shipping and fishing activities, filling bays and fjords around the island, making it inaccessible.
A satellite photo of the A23a iceberg in Antarctica was captured in November 2023. CNN
A23a is the largest iceberg in the world, with an area of 3,672 square kilometers (1,418 square miles), which is slightly smaller than Rhode Island and more than twice the size of London. Scientists have been closely monitoring the iceberg since it detached from the ice shelf, but its movement has been unpredictable. It was initially stuck on the seafloor of the Weddell Sea for over 30 years, likely until it became small enough to detach. Afterward, ocean currents carried it away, and it became stuck again in a vortex of water created by an underwater mountain.
Despite concerns, A23a has remained relatively intact, unlike other large icebergs that have broken into smaller pieces in the past. The main question now is whether the iceberg will follow the current into the open South Atlantic or if it will get stuck again on the continental shelf. "If this happens, it could seriously impede access to feeding grounds for wildlife – seals and penguins mostly – that breed on the island," Meijers said.
South Georgia is home to a rich biodiversity, including one of the world's largest Marine Protected Areas. Mark Belchier, director of fisheries and environment for the South Georgia government, is closely monitoring the iceberg’s path. He mentioned that while icebergs are common in the region, they can still cause problems for shipping and fishing vessels.
While the breakaway of A23a is likely a natural event in the ice shelf's growth cycle, scientists are concerned about the broader implications of climate change, which is driving changes in Antarctica. These shifts could lead to rising sea levels, with potentially devastating effects globally.
