Ice arches and caves: the world’s largest iceberg is crumbling

An ice colossus that is slowly disappearing. These could be the last months of life for A23a, the largest iceberg in the world, a victim of erosion and rising temperatures. On Sunday 14 January 2024, …

Ice arches and caves: the world's largest iceberg is crumbling

An ice colossus that is slowly disappearing. These could be the last months of life for A23a, the largest iceberg in the world, a victim of erosion and rising temperatures. On Sunday 14 January 2024, a ship operated by the Eyos shipping company approached the frozen giant, immortalizing its “spectacular” and at the same time worrying conditions: the iceberg appears “marked” by caves and arches dug into its walls, both from the water and from the air which becomes increasingly warmer, while the enormous ice sheet moves away from the “white continent”. A drifting journey that will bring A23a to an inevitable end: it will melt and disappear into thin air. “We saw waves 3 or 4 meters high breaking on the iceberg,” she told BBC Ian Strachan, expedition leader – we were creating icefalls, in a state of constant erosion.”

The world’s largest iceberg is crumbling

The A23a iceberg broke away from the Antarctic coast way back in 1986, but only recently began its great migration. For over 30 years it remained rigidly stuck in the muddy seabed of the Weddell Sea, like a sort of “ice island” of mammoth dimensions: approximately 4 thousand square kilometers of surface area, practically double the city of London and over three times the size of Rome. The giant is currently drifting in the Antarctic Circumpolar Current, the large expanse of water that surrounds the continent: this current will push A23a towards the South Orkney Islands, which are located 600 kilometers north-east of the tip of the Antarctic Peninsula.

This ice giant has entered what scientists call “iceberg alley”, a path that takes the giant further and further away from the Antarctic continent, headed towards the coast of South Georgia, where it will finally disintegrate. Its “legacy” will be for the inhabitants of the ocean: its dissolution will release many nutrients into the water intended for other life forms. From tiny plankton to huge whales, all beings that live in water can benefit from this particular event.

During its expedition, the Eyos team managed to get close enough to the iceberg to position a drone capable of flying over the icy cliffs, about 30 meters high and covered in thick fog. The team took several shots, which were then published by BBC: “It’s dramatic – explained videographer Richard Sidey – but also beautiful to immortalize. It’s a huge iceberg, impossible to photograph in its entirety.” In fact, only through satellite observations is it possible to monitor the area and measure the thickness of the ice, which in some areas exceeds 300 metres. Trillions of tons of ice which will inevitably decrease. The question that experts are asking is another: how much longer will A23a be able to survive as it moves away from the colder climates of Antarctica? The milder air contributes to the degeneration of the iceberg and the opening of fractures, which give “life” to the spectacular arches photographed by the Eyos team. The erosion also brought by the waves is constant, but at the moment it is difficult to make predictions about the time remaining in A23a.