Drilling to retrieve a million-year-old ice core containing critical intel about the planet's climate has begun in earnest at a remote Antarctic outpost.
Some 62 tonnes of equipment and supplies have been hauled 1200km from Australia's Casey research station to a mound of ice known as Dome C North.
The tractor traverse team of 11 people travelled 18 days through blizzards and heavy snow via a route established in 2024.
Their trek came after a two-year process of positioning equipment and drilling tests at a nearby site.
By the end of January, the team at Dome C North is aiming to have completed a 150m pilot hole and extracted ice containing the most recent 4000 years of climate history.
They want to drill 600-1200m of core per year in coming seasons.
By the summer of 2028/29, scientists hope to reach a depth of 3100m and uncover ice more than one million, and potentially two million, years old.
Palaeoclimate scientist Joel Pedro is leading the project team, which is using a drill built in Hobart by the Australian Antarctic Division.
He said bubbles of air trapped in the ice, along with natural and man-made chemical markers, provided the most detailed record of how the Earth's atmosphere and climate have changed.
"This information is pivotal to our understanding of climate and our ability to predict climate in the future," Dr Pedro said.
"This includes helping to answer a long-standing puzzle of why, before about one million years ago, there was a change in the state of the Earth's climate system to shorter ice-age cycles and smaller ice sheets."
The drill site was chosen after years of collaboration between Australian and US scientists who analysed surveys and conducted modelling.
The ice from this summer will be taken back to Casey station and then flown by C17 to Australia for analysis at the division's laboratory.
The trip to Dome C North, involving two snow "groomers" and six tractors was far from straightforward.
"We planned to drive around 80km per day but at one point there was so much soft snow we could only manage 20-30km in 10 hours," diesel mechanic Nate Payne said.
"We had to drop some of the payload to collect later and join three tractor trains together just to keep moving forward."
Dr Pedro said Australia's efforts would likely build on the work of European scientists who recently retrieved a 2800m-long core of Antarctic ice up to 1.2 million years old.
