People have been keeping track of the weather for thousands of years. The Antarctic ice, however, has been there for over a million years.
An international team of scientists has found a 1.74-mile-long (2.8 kilometer) ice core in Antarctica, which hit the bedrock of the frozen continent. The core represents a chronological record of Earth's climate and atmosphere, with the oldest ice dating back 1.2 million years, if not more. The victory, announced in a statement through the “Beyond EPICA – Oldest Ice” project, is expected to provide insight into one of climate science's most enduring questions.
It's worth clarifying that this record does not make it the oldest ice core ever obtained—that recognition goes to a 2.7-million-year-old ice core recovered in 2017. What makes the Beyond EPICA core special is its continuous, high-resolution climate record spanning 1.2 million years, which offers valuable insights into ancient atmospheric conditions and glacial cycle.
“We mark a historic moment for climate and environmental science,” said Carlo Barbante of Ca' Foscari University of Venice, coordinator of Beyond EPICA. The core was obtained during the project's fourth Antarctic campaign. “This is the longest continuous record of our past climate from an ice core, and it can reveal the link between the carbon cycle and our planet's temperature.”
Between 900,000 and 1.2 million years ago, glacial cycles switched from lasting 41,000 years to 100,000 years—a change known as the Mid-Pleistocene Transition. The Beyond EPICA project aims to better understand this ancient climate phenomenon.
Led by The Institute of Polar Sciences of the National Research Council of Italy (ISP-CNR), scientists worked for more than 200 days, drilling into the ice and processing the ice core in a remote area in East Antarctica called which is Little Dome C, with a balmy average summer temperature of -31 degrees Fahrenheit (-35 degrees Celsius).
“From preliminary analyzes recorded at Little Dome C, we have strong indications that the highest 2,480 meters [1.54 miles] contains a climate record going back 1.2 million years in a high-resolution record where up to 13,000 years are compressed into one meter of ice,” says Julien Westhoff, a postdoc at the University of Copenhagen and chief scientist in the field for the EPICA project.
The deepest and oldest part of the core, closest to the bedrock, is made of ancient ice that is “heavily altered, possibly fused or refrozen and of unknown origin,” as well as rocks from the bedrock itself. This section can help scientists better understand the refrozen ice beneath the Antarctic ice sheet, the glaciation history of this Antarctic region, and the last time the continent was ice-free.
The project still faces significant hurdles, particularly the logistical challenge of transporting the segmented ice cores to a lab without risking melting.
“The valuable ice cores obtained in this campaign will be transported back to Europe aboard the icebreaker Laura Bassi, maintained at -50°C [-58 degrees F] cold chain,” said Gianluca Bianchi Fasani, head of the Italian National Agency for New Technologies, Energy, and Sustainable Economic Development's (ENEA) logistics for Beyond EPICA. “To achieve this goal, a strategy was developed involving the design of special cold containers and precise scheduling of the National Antarctic Research Program's (PNRA) air and naval assets.”
Once the segmented ice core finds its way to a (very cold) lab, it remains to be seen what secrets researchers will unlock within the ancient climate record.
