Unlocking the Ice: Scientists Unearth 1.2 Million Years of Climate Secrets Beneath Antarctica

Researchers have drilled 1.7 miles deep into Antarctica, retrieving an ice core sample that is at least 1.2 million years old.

They anticipate that the sample will provide fresh perspectives on the development of Earth’s climate and atmosphere throughout time.

A team comprising 16 scientists and support personnel worked for four summers to bore through Antarctic ice until they reached the bedrock. To achieve this objective, they faced average temperatures of -25.6 degrees Fahrenheit at a site referred to as Little Dome C, located near Concordia Research Station.

They extracted the ice core in segments, which they will place onto an icebreaker vessel named the Laura Bassi for transit to Europe, as per a statement. Onboard, the ice cores will be maintained at -58 degrees Fahrenheit in specially designed cold containers, as reported by CBC News.

Once the cores arrive at their final destination, they can be reassembled. At a total length of 1.7 miles, the ice core exceeds the height of eight Eiffel Towers stacked on top of one another.

Cleaning and cutting ice core

Previously, the same team had extracted an ice core from Antarctica that was approximately 800,000 years old through an initiative known as the European Project for Ice Coring in Antarctica (EPICA). However, they aimed to access ice that was even older, leading them to initiate the Beyond EPICA – Oldest Ice project, which has received funding from the European Commission.

The most ancient ice ever retrieved from Antarctica was collected in 2017 and is believed to be 2.7 million years old. However, that sample was gathered closer to the surface, attributed to natural processes that elevate layers of older blue ice. The new ice core signifies the longest continuous record of Earth’s historical climate extracted from an ice core. 

Researchers indicate that ice core samples serve as valuable instruments for examining how the planet’s climate has transformed over epochs. When snowflakes descend in polar regions, they capture chemicals and particulates from the atmosphere, according to the National Science Foundation. Upon landing, these snowflakes compress into strata of ice, accumulating year after year—much like the rings of a tree.

The chemicals and particulates become locked within the layers, alongside air bubbles.

“Occasionally you can observe ash layers originating from volcanic activities,” states Carlo Barbante, a glaciologist who orchestrated the Beyond EPICA project and is also the director of the Polar Science Institute at Italy’s National Research Council, in an interview with BBC News’ Georgina Rannard. “You can see the minuscule bubbles within, some of which contain air that our ancestors inhaled a million years ago.”

When researchers extract ice cores, the youngest ice is situated at the top, while the oldest is found at the bottom. These frozen columns effectively enable scientists to look back through time.

“[Ice cores] are essentially the closest method to operate a time machine, allowing us to measure past atmospheric conditions,” notes John Higgins, a geoscientist affiliated with the National Science Foundation’s Center for Oldest Ice Research and Exploration (COLDEX), in his commentary to CBC News.

With the recent Antarctic ice core, researchers aim to discern how greenhouse gas levels have evolved over millennia. They assert that comprehending Earth’s climatic history can aid in making more precise forecasts regarding future climate scenarios.

From the 800,000-year-old ice core, for instance, they deduced that concentrations of greenhouse gases have never been as elevated as they are in the present age.

“Currently, we are observing carbon dioxide levels that stand 50 percent above the highest figures recorded over the last 800,000 years,” Barbante informs the Associated Press’s Paolo Santalucia.