Iceberg A23a, one of the world's largest and oldest icebergs, is advancing towards South Georgia, a British territory that is a wildlife paradise located about 280 kilometers away. Experts are watching the movement of A23a with concern, as many animals died in the past due to being unable to reach their feeding areas because of previous iceberg collisions.
Environmentalists are particularly worried about the impact a collision with South Georgia would have on the island's fauna, including rare king penguins and millions of elephant and fur seals. The iceberg poses a danger to South Georgia and the South Sandwich Islands, which are home to valuable colonies of these animals.
"I would be very happy if the iceberg completely missed us," remarked Captain Simon Wallace, serving on a nearby ship, according to BBC News.
A23a is one of the largest icebergs in the world, covering an area twice the size of London and is so large that it is visible from space. Currently about 3,500 square kilometers in size, it could break into large pieces as it melts in warm waters. These pieces are estimated to drift around the UK-owned islands for years.
After being stuck for decades, A23a resumed movement and is now drifting increasingly faster, posing a threat to the safety of ships in the area.
In December 2022, A23a broke free and is now on its final journey, drifting northward towards destruction, aided by meter-high waves. Warmer waters to the north of Antarctica are melting and weakening A23a's enormous ice cliffs, which rise up to 400 meters, higher than The Shard, the tallest building in London.
Large chunks of ice are breaking off from the edges of A23a and falling into the water, causing the glacier to gradually disintegrate, which is part of the normal life cycle of an ice shelf.
A23a formed by calving from the Filchner Ice Shelf in Antarctica in 1986, ran aground in the Weddell Sea, and turned into an ice island. The iceberg had been trapped in an oceanic whirlpool for months before breaking free.
"South Georgia is in a glacial alley, so the impacts are expected both for fishing and for wildlife, and both have great adaptability," said marine ecologist Mark Belchier, according to BBC News.
Scientists are taking advantage of the rare opportunity to explore how huge icebergs affect the environment. A team from the British Antarctic Survey on the research vessel Sir David Attenborough found itself close to A23a and sailed into a crack in its gigantic walls during 2023. PhD student Laura Taylor collected water samples 400 meters from its cliffs. "This isn't just water like we drink. It's full of nutrients and chemicals, as well as tiny animals like phytoplankton frozen inside," she explained, according to BBC News.
Her work looked at what effect the meltwater is having on the carbon cycle in the Southern Ocean. This process may help to naturally trap some of the carbon emissions in the atmosphere.
As Antarctica became increasingly unstable due to warmer ocean and external temperatures, larger parts of the ice sheet calved off, and more phenomena of massive iceberg calving are expected. Antarctic ice sheets are becoming more fragile due to rising ocean and air temperatures, paving the way for the formation of new giant icebergs.
In 2004, an iceberg named A38 ran aground on the continental shelf, causing penguin chicks and seal pups to die because huge chunks of ice blocked their access to feeding areas.
Mariners in the area report that icebergs are an increasing danger to the safety of ships. "All night we have the searchlights on to spot the ice. It can come out of nowhere," explained Captain Vallas, according to BBC News.
"Some pieces are the size of Wembley Stadium, others are as small as a table. They have completely covered the island's surroundings," said Andrew Newman from the fishing company Argos Froyanes,.
This article was written in collaboration with generative AI company Alchemiq