Ancient Bubbles: Unlocking the Secrets of the Ice Age

What is likely the oldest ice on the planet, estimated to be 1.2 million years old, has been retrieved from deep within Antarctica.

A team of scientists, working in conditions of -35C, managed to extract a 2.8km-long cylinder of ice – longer than eight Eiffel Towers lined up.

Encased within the ice are ancient air bubbles which researchers are optimistic will aid in deciphering a longstanding enigma regarding the climate history of our planet.

The European researchers toiled over four Antarctic summers, competing against seven countries to be the first to access the rock beneath the frozen expanse.

Their research could aid in unraveling one of the significant mysteries in our planet’s climate history – the events that transpired 900,000 to 1.2 million years ago when glacial cycles were altered and some scholars claim our ancestors nearly faced extinction.

“It’s a remarkable achievement,” remarks Prof Carlo Barbante from Ca’ Foscari University of Venice, who coordinated the project.

“In your hands, you hold a piece of ice that is a million years old. At times, you can observe ash layers resulting from volcanic eruptions. You notice the minuscule bubbles within, some containing air that our ancestors inhaled a million years prior,” he adds.

The group was spearheaded by the Italian Institute of Polar Sciences, encompassing ten European nations.

They had to move the drilling apparatus, laboratories, and camp 40km via snowmobiles from the closest research base.

The drilling site, referred to as Little Dome C, is situated on the Antarctic plateau on the eastern part of the continent, at an altitude of nearly 3000m.

Ice cores are crucial for scientists’ comprehension of how our climate is evolving.

They encapsulate air bubbles and particles that disclose levels of greenhouse gas emissions and temperature changes, assisting researchers in mapping how climatic conditions have transformed over time.

Findings from other ice cores, including one known as Epica, aided scientists in concluding that the recent temperature increase associated with greenhouse gas emissions is the result of human activities such as burning fossil fuels.

However, researchers aimed to delve further into the past.

With the initiative Beyond Epica: Oldest Ice, they have potentially uncovered an additional 400,000 years of history.

“Our future holds much of the past. By examining history, we gain insights into climate mechanisms and forecast future patterns,” remarks Prof Barbante.

Dr Robert Mulvaney, an ice core scientist from the British Antarctic Survey, notes that the team experienced “nerve-wracking final days” as they managed to drill deeper than what the radar data had suggested.

The core was extracted from the ice shelf slowly using drill equipment, while scientists meticulously cleaned the ice with cloths.

Currently, it is being segmented into one-metre pieces for transport at -50C from Antarctica by ship.

These segments will ultimately reach the freezers of several European institutions, including the British Antarctic Survey in Cambridge, where researchers will commence their examinations.

Researchers aim to decipher events that transpired during a time frame of 900,000 to 1.2 million years ago known as the Mid-Pleistocene Transition.

During this period, the cycle length between cold glacial and warm interglacial phases shifted from 41,000 years to 100,000 years, a change scientists have yet to comprehend fully.

This timeframe is also when, as per certain theories, the forebears of modern humans nearly faced extinction, potentially dwindling to around a mere 1000 individuals.

While researchers cannot ascertain if there’s a correlation between this close extinction and climatic changes, Prof Barbante clarifies, it highlights the uniqueness of this period which necessitates further investigation.

“What they may unveil is unpredictable, but it will certainly broaden our perspective on the planet’s history,” stated Professor Joeri Rogelj from Imperial College in London, who was not part of the initiative, during an interview with BBC News.

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