The world's largest iceberg is on a collision course with the British territory of South Georgia - potentially putting millions of penguins and seals in danger.
The trillion-tonne slab of ice, named A23a, broke free from its position last month and started drifting northwards.
The "megaberg" - which is twice the size of Greater London and 130 feet tall - is expected to approach the remote island off Antarctica in the next two to four weeks.
Experts fear for the island's rich wildlife. If the iceberg gets wedged in the shallow waters close to the island, it could block vital pathways for penguins to get food for themselves and their chicks.
This would mean parent penguins would have to swim further, burning more energy and bringing back less to feed their offspring.
That could "dramatically increase mortality rates" among penguins, according to British Antarctic Survey physical oceanographer Andrew Meijer - something that has happened in the past.
He examined the "colossal " iceberg up close in December 2023 when it drifted past the research ship RRS Sir David Attenborough.
"It's a huge wall, a Game of Thrones-style wall of ice that towers above the ship," he said.
"South Georgia is an amazingly ecologically rich island. It's a breeding ground for a huge number of penguins, millions of penguins and seals," Mr Meijers said.
"There's lots of pups and chicks and they're all still dependent on their parents."
While the A23a represents a threat to the penguin colony on South Georgia, it doesn't pose a greater risk to the overall penguin populations, University of Colorado ice scientist Ted Scambos said.
"The whole ecosystem in the Southern Ocean is very resilient to these events," he wrote. "It has evolved with these icebergs being a factor for hundreds of thousands of years."
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The iceberg started moving for the first time in more than three decades in November 2023, scientists said.
Before then, it had largely been stranded after its base became stuck on the floor of the Weddell Sea.
Eventually, the A23a will break up into smaller icebergs and melt as icebergs do, Mr Meijers said.
Icebergs breaking off is normal, but it is happening more frequently as the climate warms and more fresh water flows into the ocean, Mr Meijers said.
(c) Sky News 2025: World's largest iceberg on crash course with island, putting millions of penguins in danger
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