28-06-2025
Antarctic scientists analyse first samples from 'Million Year Ice Core' project
Inside an ice-cold laboratory in Hobart, where the temperature is almost 20 degrees Celsius below zero, scientists in thick puffer jackets begin their work.
Wearing gloves, they carefully pull out a one-metre cylinder of ice from an insulated box that recently arrived from Antarctica.
"In the freezer lab today, we're cutting the first samples from the 'Million Year Ice Core'," Dr Joel Pedro explained.
For almost a decade, the paleoclimatologist and a team from the Australian Antarctic Program have been planning an ambitious project.
Known as the 'Million Year Ice Core', the aim is to extract the world's oldest, continuous core of ice from deep beneath the frozen continent.
"More than any other archive of climate in the past, [ice cores have] a range of information that helps you to understand the changes in the total climate system," Dr Pedro said.
In other words, ice cores are like time capsules that allow scientists to get a clear picture of the Earth's climate and atmospheric history.
That's because they contain tiny bubbles of air trapped over thousands, and even millions of years, depending on the depth of the ice.
The ice that's being analysed in the Hobart laboratory comes from a depth of 150 metres, making it almost 4,000 years old.
While it's a significant milestone, it's only the start of a much bigger mission.
Over the coming years, the team hopes to reach a depth of 3,000m.
If successful, it will be the oldest ice ever recovered.
Getting to this point has been a mammoth logistical undertaking.
The drill site, known as Dome C North, is 1,200 kilometres from the nearest Australian station in Antarctica.
It's also 3,000m above sea level, where the temperature can fall below minus-50 degrees Celsius.
Turning the site into a deep field station involved a 10-person team using six tractors to haul almost 600 tonnes of gear across the frozen landscape.
"In the Australian program, it's the biggest traverse that we've undertaken," traverse leader Chris Gallagher, from the AAD, said.
After enduring multiple blizzards, the team eventually made it to Dome C North 18 days after setting off from Casey Station.
"It's a very specialised team that has extremely high skills, but also that ability to really get on with each other and care for each other," Mr Gallagher said.
Once the accommodation modules and drill shelter were set up, a separate team of scientists flew in to begin drilling and processing the ice core.
Chelsea Long, a field assistant, said the extraction of the first section of ice was a momentous occasion.
"It was really celebratory when it came out and just finally to see this happening and to touch the ice and measure it, was a real joy," she said.
For Dr Pedro, it was a moment to savour after many years of hard work, as well as delays caused by the COVID pandemic.
"The start to the project was easily the most exciting thing that's happened in my science career," he said.
"But at the same time, it's just the start of the project — we've [still] got 3 kilometres to go."
Currently, the oldest ice core on record dates back almost 800,000 years.
But a European team, known as Beyond EPICA, recently extracted ice from a depth of 2,800m, which is expected to date back almost 1.2 million years.
The Australian team plans to drill more than 200m deeper than Beyond EPICA, which Dr Pedro said could date back up to 2 million years.
"If we can get this record − and the modelling suggests [Dome C North] is the best site in Antarctica for recovering [the] oldest ice − then we'll produce data that will stand for decades as the measurement of Earth's atmosphere [and] greenhouse gas levels through that period."
If successful, that data would help scientists better understand why the Earth's ice ages became much longer about a million years ago.
"It remains one of the biggest puzzles, [or] challenges, in ice core science and in climate science to resolve what the cause of that was, and, in particular, what the role of C02 [carbon dioxide] was in that."
Data from the 'Million Year Ice Core' could also improve the accuracy of climate change forecasts.
The team plans to resume drilling during the 2025/26 summer and expect to reach the 3,000m-mark in 2028/29.
