A global team of researchers has pulled off an impressive feat by drilling down and extracting a massive ice core from Antarctica that stretches an incredible 9,186 feet (or 2,800 meters) long, dating back a whopping 1.2 million years! They went so deep that they actually hit the bedrock beneath the Antarctic Ice Sheet.
Just to give you an idea of how long that is, this core is about the length of 25 soccer fields lined up in a row or around six and a half times taller than the Empire State Building if you include its antenna. Carlo Barbante, who leads the Beyond EPICA project (European Project for Ice Coring in Antarctica), referred to it as a “time machine” filled with a remarkable record of Earth’s climate history.
The team has chopped the core into manageable 3.2-foot (1-meter) sections and packed them away in insulated boxes for further research. Barbante, who’s a professor at Ca’ Foscari University of Venice in Italy and a senior associate at the Institute of Polar Sciences with the National Research Council of Italy, emphasized the importance of these samples.
They collected the core from Little Dome C, which is known as one of the toughest and most extreme spots on Earth. Located about 21 miles (34 kilometers) from the Italian-French Concordia research station, this site faces relentless strong winds and temperatures that hover below minus 40 degrees Fahrenheit (or minus 40 degrees Celsius) almost all the time.
This ice core, among the oldest ever retrieved, has the potential to unlock answers to some of the biggest questions we still have about how our planet’s climate has evolved over millions of years.
Barbante shared in an email that the air bubbles frozen in ice cores are like time capsules, giving us a clear glimpse into what the atmosphere was like in the past, including levels of greenhouse gases such as carbon dioxide and methane.
“By studying these bubbles, we can piece together how Earth’s climate reacted to different factors that influence climate, like changes in solar radiation, volcanic eruptions, and shifts in Earth’s orbit. This information is crucial for understanding the complex link between greenhouse gases and global temperatures over hundreds of thousands of years, stretching back as far as 1.2 million years and hopefully even further,” he explained.
Researchers are also eager to see what insights the ice might offer about why Earth’s ice ages suddenly changed around a million years ago—an event that nearly led to the extinction of our ancient human relatives, according to recent findings.
A frosty achievement!
Researchers got their hands on a core sample during the fourth expedition of the Beyond EPICA – Oldest Ice project, which is backed by the European Commission. This campaign unfolded during the most recent Antarctic summer, running from mid-November to mid-January. Over the last four summers, experts from 12 different European research institutions have dedicated more than 200 days to drilling and analyzing this ice.
This initiative builds on the groundwork laid by the earlier EPICA project, which took place from 1996 to 2008. Back then, scientists drilled deep into the ice, uncovering crucial links between climate changes and atmospheric greenhouse gas levels over an impressive 800,000-year period. The core they collected in this latest endeavor represents a significant step forward, providing a continuous record of Earth’s climate that stretches even further back in time.
Investigations of the original EPICA core revealed that Earth goes through a cycle of roughly 100,000 years marked by cold glacial periods (or ice ages) alternating with warmer phases. However, this pattern didn’t quite align with marine sediment studies indicating that Earth experienced glacial cycles of about 41,000 years before reaching the million-year mark.
Launched in 2016, the Beyond EPICA project aims to discover older ice that could help explain why this transition took place. The search for the perfect drilling site began with radar surveys.
Using radio echo sounding technology allowed the team to pinpoint ice that could serve as a time capsule, according to Frank Wilhelms, the lead investigator and a professor at Göttingen University and the Alfred Wegener Institute in Germany.
“We were on the lookout for a ‘Goldilocks’ site—ice that’s thick enough to provide a detailed climate record at great depths, but not so thick that the oldest layers had melted away,” explained Dr. Robert Mulvaney, a glaciologist and paleoclimatologist at the British Antarctic Survey.
“Sometimes, heat from the Earth’s mantle gets trapped beneath a thick layer of ice, which can lead to melting, especially if that ice is really thick,” Mulvaney explained. “That’s why we put so much effort into scouting out the best locations for our drilling before we even started.”
Little Dome C sits high on the central Antarctic plateau, soaring to about 10,498 feet (3,200 meters) above sea level, and it comes with its own set of challenges. The team had to be careful to avoid any drill malfunctions and make sure the electromechanical core drill was moving smoothly through the ice layers.
According to Julien Westhoff, who’s the chief scientist on-site and a postdoctoral researcher at the University of Copenhagen in Denmark, each meter of ice holds up to 13,000 years’ worth of climate history!
Discoveries from Ancient Ice
When the team finally pulled up the ice core, they hit the jackpot. The lowest 688 feet (or 210 meters) of the core, sitting just above the bedrock, is made up of really old ice that’s been through a lot—it’s all deformed and likely a mix of different layers, refrozen and with origins still a mystery.
Studying this ice could shed light on how it refroze under the ice sheet. The researchers are also keen to see if there’s even older ice lurking around, possibly dating back to the pre-Quaternary Period, which is about 2.58 million years ago. Plus, they plan to date the rocks below the ice to find out when this part of Antarctica was last free of ice.
“It was thrilling to witness the ice age unfold as we drilled deeper, especially knowing we were tapping into ice that predates the EPICA record, which only goes back 800,000 years,” said Mulvaney from the British Antarctic Survey. “With this new record stretching back 1.2 million years, we’ll have several glacial cycles of 41,000 years each to compare with the newer data from the original EPICA core.”
Barbante pointed out that the Mid-Pleistocene Transition, which happened between 1.2 million and 900,000 years ago, represents a major change in Earth’s glacial patterns.
“This transition is still a bit of a puzzle for scientists, especially when it comes to understanding the impact of greenhouse gases and how ice sheets behaved,” he explained. “The Beyond EPICA ice core presents a unique chance to measure atmospheric conditions during this crucial time, which could help us figure out why this transition happened and what it meant for our planet’s climate system.”
So, back during the Mid-Pleistocene Transition, things got pretty chilly and dry for a long time. Ice ages stretched out longer and hit harder, which really dropped the temperatures around the globe. Around 930,000 to 813,000 years ago, the human population took a big hit too, shrinking down to just about 1,280 breeding individuals.
And get this – it stayed that way for roughly 117,000 years! A study from 2023 in the journal Science suggests that this was a critical moment that nearly wiped out our human ancestors, though not everyone is convinced by that idea.
Still, those ice cores might hold some clues about what caused these ice ages to last longer.
There’s a certain vibe in the atmosphere, like little bubbles floating around.
Ice cores are fascinating time capsules that capture layers of snowfall compressed over the years. Inside these layers, tiny air bubbles and particles are trapped, and scientists can analyze them to understand how Earth’s temperature and atmosphere have changed over time.
These cores could be key for researchers looking to piece together Earth’s climatic past, helping them make better predictions about future changes. They also provide insights into how our planet reacts to varying levels of greenhouse gases.
Jim White, the Craver Family Dean of the College of Arts and Sciences at the University of North Carolina at Chapel Hill, likens Antarctic ice cores to Rosetta Stones. He mentions in an email that they uniquely convey information about both temperature and carbon dioxide levels, allowing us to see how these crucial climate factors are interconnected.
Although White wasn’t part of the team that collected the ice core, he believes it holds a wealth of knowledge regarding the fundamental processes of climate change. He emphasizes that understanding this information is incredibly important.
While some initial analysis has taken place on-site, the ice core samples will be carefully transported back to Europe on the icebreaker ship Laura Bassi, kept in specially designed cold containers to ensure they stay at the right temperature. Barbante expects this research will be a long-term project as scientists thoroughly investigate the gas concentrations and dust particles embedded in the ice.
At the same time, the Beyond EPICA project and other global collaborations are on the lookout for even older ice that could provide longer climate records. However, Barbante notes that finding such sites will require advanced technology and careful planning.
“We need to identify additional locations in Antarctica where we can collect continuous climate records similar to what we’re currently examining,” he explains.There’s a certain vibe in the atmosphere, like little bubbles floating around.