Inside an ice-cold laboratory in Hobart, where temperatures plunge nearly 20 degrees Celsius below zero, scientists clad in thick puffer jackets embark on a groundbreaking mission. With gloved hands, they carefully extract a one-meter cylinder of ice from an insulated box recently transported from Antarctica. This marks the first step in analyzing samples from the ambitious ‘Million Year Ice Core’ project.
“In the freezer lab today, we’re cutting the first samples from the ‘Million Year Ice Core’,” explained Joel Pedro, the lead scientist from the Australian Antarctic Division. “And that’s a big moment for us.”
The Significance of Ice Cores
For nearly a decade, Dr. Pedro and his team from the Australian Antarctic Program have been planning this ambitious project. The goal is to extract the world’s oldest continuous core of ice from deep beneath Antarctica’s frozen expanse. Ice cores, often described as time capsules, provide a window into Earth’s climatic and atmospheric history. They contain tiny air bubbles trapped over thousands, even millions, of years, offering pristine samples of past atmospheres.
“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 emphasized. “Those air bubbles are a sample of the atmosphere in the past that was trapped as snow fell and was then compressed into ice.”
“We’re hoping to push the climate record back well over a million years, potentially up to 2 million years,” Dr. Pedro said.
Logistical Challenges and Triumphs
The ice currently being analyzed in Hobart comes from a depth of 150 meters, dating back almost 4,000 years. While this is a significant milestone, it marks only the beginning of a much larger mission. Over the coming years, the team aims to reach a depth of 3,000 meters, potentially recovering the oldest ice ever.
Reaching this point has been a monumental logistical feat. The drill site, Dome C North, is located 1,200 kilometers from the nearest Australian station in Antarctica and sits 3,000 meters above sea level, where temperatures can drop below -50 degrees Celsius. Transforming the site into a deep field station required a 10-person team using six tractors to transport nearly 600 tonnes of equipment across the icy terrain.
“In the Australian program, it’s the biggest traverse that we’ve undertaken,” said Chris Gallagher, the traverse leader from the Australian Antarctic Division.
After enduring multiple blizzards, the team reached Dome C North 18 days after departing from Casey Station. “It’s a very specialized team with extremely high skills, but also the ability to really get on with each other and care for each other,” Gallagher added. “We were like a big family on this trip.”
Celebrating Milestones Amidst Challenges
Once the accommodation modules and drill shelter were established, a separate team of scientists arrived to commence drilling and processing the ice core. Chelsea Long, a field assistant, described the extraction of the first section of ice as 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, this moment was a culmination of years of hard work and perseverance, especially in the face of delays caused by the COVID-19 pandemic. “The start to the project was easily the most exciting thing that’s happened in my science career,” he remarked. “But at the same time, it’s just the start of the project — we’ve still got 3 kilometers to go.”
Unlocking Earth’s Climate Mysteries
Currently, the oldest ice core on record dates back nearly 800,000 years. However, a European team, known as Beyond EPICA, recently extracted ice from a depth of 2,800 meters, expected to date back almost 1.2 million years. The Australian team plans to drill more than 200 meters deeper than Beyond EPICA, which Dr. Pedro suggests could date back up to 2 million years.
“If we can get this record − and the modeling 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,” Dr. Pedro explained.
If successful, this data could provide crucial insights into why Earth’s ice ages became significantly 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 CO2 was in that,” Dr. Pedro noted.
The data from the ‘Million Year Ice Core’ could also enhance the accuracy of climate change forecasts, offering a clearer picture of future climate scenarios. The team plans to resume drilling during the 2025/26 summer and expects to reach the 3,000-meter mark by 2028/29.
