Australia’s Antarctic Quest: Unveiling Ancient Ice Secrets at the World’s Most Isolated Outpost

Trekking across the world’s most brutal continent necessitates a substantial dose of resilience. “We took risks, and we acknowledged them,” noted Antarctic explorer Robert Falcon Scott in 1912, ensnared by a savage blizzard in the moments leading up to his demise, during an ill-fated mission to reach the South Pole. “Circumstances have conspired against us, and thus we have no reason for grievance.”

Over a century later, elemental extremes remain a stark reality for researchers in Antarctica. In spite of three seasons of misfortune that have postponed his team’s endeavor to locate the world’s oldest ice, paleoclimate scientist Dr. Joel Pedro stays optimistic. He has justifiable grounds for this: this summer, following numerous setbacks and a relocation, a plan years in development is at last materializing.

Pedro communicates with Guardian Australia from a site elevated upon the Antarctic plateau, where the current daytime temperature hovers around -30C. He is the chief scientist for Australia’s Million Year Ice Core project, which is searching for – as its designation implies – ice that formed over a million years ago. Bubbles of ancient air entrapped in that ice will reveal insights about Earth’s historical climate and assist scientists in predicting the future, as CO2 levels in the atmosphere continue to rise due to human activities.

The prior Antarctic season proved particularly challenging. To initiate ice drilling, a 500-ton convoy had to undertake a 1,200km journey inland from the Casey research station to the drilling site in East Antarctica, designated as Little Dome C. However, at Casey, chaos ensued: half of the traverse team contracted Covid.

“No one was critically ill,” Pedro explains, but several expedition members needed to be evacuated to Australia. Little Dome C stands at 3,230 meters above sea level, causing worries over whether the high altitude would hinder their recovery. The traverse experienced a five-week delay.

Pedro and his colleagues were slated to fly from Casey station to Concordia, situated about 10km from the drilling site, to connect with the traverse team. However, Casey, located on the Antarctic coastline, is susceptible to severe weather – three blizzards swept through, delaying the crew. Time was becoming scarce, as the season neared its conclusion: post-January, temperatures could plummet to -50C to -60C, an environment too frigid for machinery operation. The difficult choice was to forgo drilling.

Simultaneously, a European ice core initiative, located merely 4km away, made headway. Named Beyond Epica, this team from 10 nations had a few years’ advantage over the Australians. Last week, they reached the bedrock beneath the Antarctic ice sheet, retrieving a 2.8km-long ice core, the base of which is believed to contain ice that is 1.2 million years old.

The disappointing start to the 2023-4 season confronted the Australians with a conundrum: should they wait an additional year to commence drilling in the same location as the Europeans, or should they initiate anew at a completely different site? Fresh modeling and radar imaging, released mid-2023, indicated that another site located 45km away, Dome C North, contained ice that was significantly deeper and older – ice that could reach depths of 3.2km, dated well beyond 1.2 million years and potentially up to 2 million years old.

This revelation turned out to be a fortunate outcome of the previous season’s setbacks, according to Pedro, who experienced “many sleepless nights” over the choice to change locations. The team is set to drill in Antarctica over the next five years, and will analyze the ice cores in the lab over the subsequent decade; if the new site can yield older ice than what the Europeans have discovered, scientifically, it justified the relocation.

In December, a 642-ton convoy departed from Casey station for the overland journey. They reached Dome C North, the newly designated drilling site, after 18 days on Christmas Eve, and subsequently celebrated with a Christmas party organized by the French and Italians at the nearby Concordia station. Following a “quite devastating” last season, “it’s been incredibly enjoyable to actually work in the field,” states Nate Payne, the mechanical supervisor of the traverse team.

The scientific and drilling crew arrived at Concordia on New Year’s Eve. In the following two weeks, they constructed a permanent drill shelter, a 27-meter structure that will last for the next five years, accommodating a drill exceeding 8 meters in length and able to withstand temperatures as low as -80C.

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On Tuesday, the drilling of the ice core officially commenced. Within two days, the team had reached a depth of 80 meters. “It seems incredible after seasons where very little progressed due to various logistical difficulties,” remarks Pedro.

The team aims to reach 150 meters by the end of January, retrieving ice cores that offer a climate history of the last 4,000 years. Over the next five years, the primary drill will extract 3-meter-long ice cylinders at a time, continuing until it encounters bedrock more than 3km below.

When the ice cores emerge from the barrel, they are cleaned, measured, weighed, and sliced into 1-meter segments, explains Chelsea Long, a PhD candidate at the University of Tasmania, responsible for processing the cores. “They’re coming out at roughly -55C,” she notes. “You can’t touch them with your bare hands. I made that error this morning.

“In subsequent seasons, because the ice is under significant pressure during extraction, it must be brought up very, very slowly, otherwise it risks cracking,” she states.

The ice will eventually be transported to Australia, at temperatures well below freezing, for analysis: oxygen isotopes to provide a record of temperature variations; chemical assessments for traces of continental dust or signs of ancient volcanic activity; and, importantly, fluctuations in the levels of greenhouse gases over time.

If the team can retrieve an ice core older than 1.2 million years, it will extend the climate record beyond a period referred to as the mid-Pleistocene transition, when Earth transitioned to shorter ice age cycles and smaller ice sheets.

“It’s about comprehending long-term climate stability and what influences the Earth’s climatic condition,” Pedro states. “It will be a significant addition to our knowledge of Earth’s historical climate, which is essential for evaluating models that predict future climate.”