A British man has become the first person in recorded history to swim underneath an ice sheet in Antarctica – and he did it wearing only swimming trunks, a cap and goggles.
Lewis Pugh from Plymouth swam in the Antarctic river beneath the largest glacier on the planet.
The 50-year-old is seen in photographs swimming through a blue tunnel of ice, with melting ice falling into the water around him.
The water is thought to only be a few degrees above zero and Mr Pugh spent around eight minutes in the water, without the protection of a drysuit.
Mr Pugh, who is an endurance swimmer and campaigner for climate change awareness, completed a trial swim on Monday 20 January and another on Thursday 23 January.
The training swims are in preparation for another 20-minute swim in freezing conditions later this week.
The final swim will see Mr Pugh attempt to become the first person ever to swim across an entire supra-glacial lake, which is a body of water formed on the surface of a melting ice cap.
There is an added danger of the lake succumbing to a large hole, known as a moulin, causing the water (and Mr Pugh) to plummet hundreds of metres to the continent’s bedrock.
The swimmer described the ice sheet as one of the “most beautiful places” he’d ever encountered.
He said: “This is one of the most remote places on the planet. It’s vast. It’s beautiful. But everywhere we look we are seeing meltwater.
“It was every shade of blue. It started turquoise, and then I swam around a corner and it was royal blue. And then it turned to indigo, and then a psychedelic blue, and finally violet.”
Despite enjoying the swim, Mr Pugh said he was “quite relieved” to see his team at the end of the tunnel. “This is a high-consequence environment to swim in,” he says.
Mr Pugh said 33 years of training allowed him to swim for those eight minutes and thanked the team of French mountaineers who helped him get into the crevice to swim.
In 2007, he became the first person to complete a long-distance swim across the geographic North Pole.
The 1km crawl across an open patch of sea was to highlight the melting of the Arctic sea ice.
He was also the first person to complete a long-distance swim in every ocean of the world.
In July 2019 scientists found underwater glacial melting was happening up to 100 times faster than previously thought.
For the first time, researchers directly measured the melting of tidewater glaciers below the waterline. They found existing models were “wildly inaccurate”.