A 1.2-million-year-old ice core has been extracted from the heart of Antarctica, making it the oldest ice on Earth.

A recently discovered ice core from Antarctic ice dating back 1.2 million years is the oldest known ice on Earth. The length of the ice core, extracted from the very heart of the ice continent, reaches 2.7 kilometers and was retrieved from a depth of over 2800 meters, where the Antarctic ice sheet meets the bedrock, reports Popular Science.

The drilling was completed in early January 2024 and took place in southeastern Antarctica. The study was conducted by an international team of scientists from 10 countries, aimed at reconstructing a piece of Earth's natural history that is little known today.

According to the lead researcher in this field and postdoctoral fellow at the University of Copenhagen, Julien Westhoff, preliminary analysis indicates that there is strong reason to believe that the top 2,480 meters contain a climate record that dates back 1.2 million years, with high resolution where up to 13,000 years are compressed into one meter of ice.

This recently extracted ice has preserved part of the record of Earth’s climate history — a continuous account of atmospheric temperatures, as well as some samples of ancient air containing greenhouse gases.

According to another co-author of the study, Professor Carlo Barbante from the University of Venice Ca' Foscari, this ice core actually represents the longest continuous record of our past climate. Scientists also believe that this core sample could reveal the relationship between the carbon cycle and Earth’s temperature.

During the study, researchers employed radio-echo sounding technologies and advancements in ice flow modeling to accurately determine the drilling area. The lower slightly over 200 meters of the ice core above the bedrock, as the study shows, consists of old ice that is heavily deformed. Scientists believe it is likely mixed or refrozen, and has an unknown origin. The study's authors plan to continue their research to test some previous theories about the behavior of refrozen ice hidden beneath the Antarctic ice sheet. Researchers also hope to uncover more information about the glacial history of East Antarctica.

Moreover, the ability to look so deep into the heart of Antarctica may help scientists answer one of Earth's major climate mysteries: what occurred when glacial cycles were disrupted between 900,000 and 1.2 million years ago. Some scientists believe that during this period, our ancestors were close to extinction, yet they managed to survive.