A massive iceberg named A23a, weighing nearly 1 trillion metric tonnes, has come to a stop off the island of South Georgia in the southern Atlantic Ocean. The iceberg, which is slightly smaller than Rhode Island and more than twice the size of London, had been drifting since 2020 after calving from the Filchner Ice Shelf in Antarctica.
According to the British Antarctic Survey, A23a got stuck for months spinning around an undersea mountain before finally breaking free and running aground. Initially, concerns were raised that it would head towards South Georgia and impede access to feeding grounds for seals and penguins. However, experts now believe that if the iceberg stays grounded, it will not significantly affect local wildlife.
In fact, the arrival of A23a could have some benefits for wildlife, as nutrients stirred up by its grounding and melt may boost food availability for the regional ecosystem. Large icebergs like A23a tend to break up quickly due to increased stresses, but scientists say that global warming is driving worrying changes in Antarctica.
While A23a’s break-up is inevitable, it will pose a hazard to fishing and shipping operations as smaller icebergs are harder to detect and track. The smaller icebergs produced by A23a will also be more hazardous than the original megaberg. As global sea level rise concerns continue to grow, scientists say that this particular iceberg probably broke away due to natural growth cycle changes rather than climate change.
Source: https://edition.cnn.com/2025/03/04/science/a23a-iceberg-runs-aground-scli-intl/index.html