Scientists Drilled 1.7 Miles Into the Antarctic Ice Sheet and Found a Million-Year-Old Secret

To a layman, Antarctica’s ice may just be ice. But for geologists, this ice is a time machine, much like the Egyptian hieroglyphics or the Greeks’ Rosetta Stone. The ice encapsulates within it hoards of valuable information about the continent’s climate history, the temperature cycles, and overall evolution of the ice dynamics. Even the tiny air bubbles trapped within this ice are fascinating storytellers that lock within them the tales and backstory of this ice.

Recently, an international team of researchers drilled the Antarctic ice sheet and extracted a colossal 2,800-meter (9,186-foot) long ice core, which is equivalent to the length of the Golden Gate Bridge. Analysis of the core’s fragments revealed that it was 1.2 million years old, probably containing the record of “world’s oldest ice,” as reported by a British Antarctic Survey (BAS) press release.

“We have a strong indication that the uppermost 2,480 meters contain a climate record that goes back to 1.2 million years in a high-resolution record where up to 13,000 years are compressed into one meter of ice,” Julien Westhoff, chief scientist in the field, and postdoc at Copenhagen university, said in the press release. And although 1.2 million years sounds ancient enough, the scientists believe that there is even more potential for yet an older ice, which could date back to the pre-Quaternary period, about 2.58 million years ago. This prehistoric ice could be discovered in one of the many fragments that the team had to carve off from the main ice core.

“The team has sliced the core into 3.2-foot (1-meter) pieces stored in insulated boxes so they may be studied,” Barbante, professor at Italy’s Ca’ Foscari University of Venice, told CNN. The core was retrieved from Little Dome C, one of the harshest and most extreme locations on the planet, featuring bitterly whipping winds and freezing temperatures as low as minus 40 degrees Fahrenheit.

This project was part of the “Beyond EPICA-Oldest Ice” campaign coordinated by the Institute of Polar Sciences of the CNR. Carlo Barbante, coordinator of this project, said to CNN that this ice core is “a time machine that captures an extraordinary archive of Earth’s climate.” And although the oldest ice discovered so far dates back to 2.7 million years ago, this particular ice has been pushed beneath the layers of thick ice by Earth’s movements. As a result, the ice no longer provides a consistent snapshot of the climate history.

Retrieved ice cores, on the other hand, are excellent historic caches because they trap particles, water isotopes, and bubbles of atmospheric gases that can provide a treasure trove of information. Barbante explained to CNN that by analyzing the “air bubbles trapped in ice cores,” scientists can “reconstruct how Earth’s climate responded to changes in climate forcing factors, such as solar radiation, volcanic activity, and orbital variations.

Investigating these ice cores is like taking a train to millions of years in the past and witnessing what the climate looked like at that time and how Earth’s natural glaciation cycles shifted over the years. "This transition remains a scientific mystery, particularly regarding the role of greenhouse gases and ice sheet dynamics. This data helps us understand the intricate relationship between greenhouse gases and global temperature over hundreds of thousands of years and now down to 1.2 million years and hopefully beyond," Barbante concluded.