Ancient ice from Antarctica, extracted as part of the Beyond EPICA - Oldest Ice project, captures a unique climate record spanning at least the past 1.2 million years.
The team at the British Antarctic Survey (BAS) in Cambridge, together with collaborators from across Europe, have successfully analysed 190 metres of ice from the bottom of a 2800-metre ice core. Melting and analysis of the ice finishes this week (as of Friday 3 October).
The ice cores were retrieved from Little Dome C in East Antarctica over several years for an ambitious project that started over a decade ago. Analysing the chemical composition of the ice will reveal past climate and environmental conditions and are the gold standard for scientists. This is because they provide a continuous record of past climates using robust chemical markers.
A team of 30 researchers, engineers and experts from BAS and European research institutes have spent over seven weeks continuously melting each section of the precious ice core.
The researchers confirm they have captured a complete record of past climate and atmospheric composition stretching back at least 1.2 million years. The melting process has revealed an unbroken sequence of climate cycles, providing the oldest continuous ice core record ever recovered.
The resulting data will now undergo comprehensive analysis at laboratories across Europe, including at BAS, to unlock secrets about the Earth's climate evolution and greenhouse gas concentrations.
Funded by the European Commission, Beyond EPICA - Oldest Ice brings together researchers from 10 European countries and 12 institutions. The project's ultimate aim is to reconstruct up to 1.2 million years of Earth's climate history, significantly extending the current oldest ice core record of 800,000 years which has been the benchmark for the last 20 years.
Dr Liz Thomas, Head of the Ice Cores team at British Antarctic Survey, said:
"This is a historic moment - we now have the longest continuous record from ice cores, providing a blueprint to our Earth's climate. It's been a huge feat to get to the stage where we have now melted 190 metres of the oldest parts of the ice core. While the true age of the ice will only be determined once all the data has been collated, our best estimates are that we have exceeded 1.2 million years. It's been high pressure, a huge team effort and massively rewarding to get to this stage and to the end.
"The analysis of this melted ice is important. We all want to understand why the planet's climate cycle shifted roughly one million years ago from 41,000-years to 100,000-years. By extending the ice core record beyond this turning point, we hope to improve predictions of how Earth's climate may respond to future greenhouse gas increases."
The British Antarctic Survey ice core team are specialists in continuous flow analysis-a cutting-edge technique that involves the ultra-slow melting of ice core sections to simultaneously measure a suite of chemical elements, particles, and isotopic data. Their expertise, and support from UK Research and Innovation (UKRI), enabled the team to be selected to lead the impurities analysis of the oldest Antarctic ice core ever recovered. Other European Labs will analyse the ice cores for greenhouse gases (CO2 and methane).
Until now, the scientific community has relied on marine sediment cores to explore the climate cycles over millions of years. These marine records play an important role in constraining the timings of glacial-interglacial cycles. The unique feature of the ice cores is that their entrapped bubbles capture the atmospheric conditions, changes in greenhouse gas concentrations and chemical evidence of the past temperatures at the time they were deposited.
The Beyond EPICA - Oldest Ice Core project, funded by the European Commission, is coordinated by Italy through the Institute of Polar Sciences of the National Research Council (Cnr-Isp) and led by Carlo Barbante, Professor at Ca' Foscari University of Venice and senior associate member at Cnr-Isp, with a research team comprising 12 scientific institutions from 10 European countries. The project is supported by national partners and funding agencies in Belgium, Denmark, France, Germany, Italy, Norway, Sweden, Switzerland, the Netherlands, and the United Kingdom.
This project has received funding from the European Union Horizon 2020 research and innovation programme under grant agreement No. 815384.
