Scientists drill 600m into ice to unlock West Antarctica's frozen past

An international team of scientists have unlocked secrets from the deep, as they seek to understand the warming threshold for losing the West Antarctic Ice Sheet. 

Using a mixture of cutting-edge technology and elbow grease, they've been able to extract sediment dating back thousands of years. 

They're drilling into the past for a glimpse into the future. 

"We're going to drill through the ice shelf. It's about 600m thick, where we're standing," said Richard Levy, SWAIS2C Project co-chief scientist. 

"The deeper down we drill into the mud and sand deposited at the ocean floor, the further back in time we go," said Tina van de Flierdt, also co-chief scientist. 

They aim to unearth clues that could be millions of years old, when temperatures were 1-3C, or even 4C warmer than today. 

Van de Flierdt and Levy are at the point where the West Antarctic Ice Sheet meets the floating Ross Ice Shelf. 

"So, we're... here to try to find that compelling piece of evidence that says, 'For sure, the ice shelf that we're standing on will collapse under an increase in temperature of 1.5C.' Or maybe we have a little bit more room to move," said Levy. 

"As the ice shelf collapses, as the ice sheet retreats, water flows into the ocean [and] the sea level goes up," said van de Flierdt.

The scientists are drilling ice cores about 600m deep.
The scientists are drilling ice cores about 600m deep. Photo credit: Newshub.

And the pair believe that could be between 3-5m. 

"To access those archives, those geological records that that lie deep beneath the location in which we stand, we need to melt a hole through the Ross Ice Shelf. We need to melt a hole 600m deep until we break out into the ocean cavity," van de Flierdt said. 

"But the hole is constantly wanting to freeze - it's wanting to close up," said Levy. 

Once they hit the bottom, extracting the sediment requires a mix of cutting-edge technology - and elbow grease. 

"It's a 3m-long tube and it has some sliding weights on a rod at the top that we can pull from the surface and let go," said drilling coordinator Gavin Dunbar. "And you pull it back, let it go and progressively hammer the core into the seabed." 

The result was the longest ice core ever drilled in this crucial location. 

"We did see a couple of fish, of which I've got no idea what it means but it's cool to see them there," Dunbar said. 

Exactly what else they've found will be discovered in the lab. 

"I think it's our duty as scientists to keep doing the research; to not be labelled as alarmists but provide the data which show where the tipping points are," said van de Flierdt. 

"This year, we got tantalisingly close, I can feel the secrets beneath my feet," Levy added. 

The scientists will be back in 2025 to dig deeper.