A decade ago, the European EPICA project completed drilling a deep ice core at Dome C, revealing the close link between climate and atmospheric greenhouse gases over the past 800,000 years. The record showed that the Earth’s climate experienced a 100,000 year cycle of cold glacial periods (ice ages) interspersed with warmer interglacials. But marine sediment records show that earlier than one million years glacial periods occurred once every 41,000 years. We feel that the clue to the change in glacial frequency lies in the greenhouse gases in the atmosphere, so a team of European scientists intend to drill another ice core that we hope will reach back 1.5 million years.
Candidate sites for the ‘Oldest Ice’ drilling project have been chosen using ice sheet modelling, but need field observations to confirm and select the best site. We will deploy our Rapid Access Isotope Drill (RAID) at candidate sites near to Dome C to recover ice back to the last glacial period to confirm age-depth models, and measure the borehole temperature to check for absence of melting at the bed. We will use two BAS radars (ApRES and DELORES) to provide supporting detail of the local ice sheet dynamics.
To better constrain the response of Earth’s climate system to continuing emissions, it is essential to turn to the past. A key advance would be to understand the transition in Earth’s climate response to changes in orbital forcing during the ‘mid-Pleistocene transition’ (900 to 1200 thousand years ago) and in particular the role of greenhouse gases. Unravelling such key linkages between the carbon cycle, ice sheets, atmosphere and ocean behaviour is vital for society to better design effective mitigation and adaptation strategies. Only ice cores contain the unique and quantitative information about past climate forcing and atmospheric responses. But the ice providing essential evidence about past mechanisms of climate change more than 1 Ma ago required for our understanding of these changes (termed the “Oldest Ice” core), has not been found to date.
The consortium Beyond EPICA – Oldest Ice (BE-OI), formed by 14 European institutions, takes on this challenge to prepare the ground for obtaining 1.5 million year old ice from East Antarctica. BE-OI has the objectives to:
support the site selection through acquisition and synthesis of all necessary information on Antarctic sites through specific geophysical surveys and the use of fast drilling tools to qualify sites and validate the age of their ice;
select and evaluate the optimum drill site for the future “Oldest Ice” core project and establish a science and management plan for a future drilling;
coordinate the technical and scientific planning to ensure the availability of the technical means to implement suitable drill systems and analytical methodologies for a future ice-core drilling, and of well-trained personnel to operate them successfully;
establish the budget and the financial background for a future deep-drilling campaign;
embed the scientific aims of an “Oldest Ice” core project within the wider paleoclimate data and modelling communities through international and cross-disciplinary cooperation.
BAS glaciologist Dr Robert Mulvaney journeys deep into Antarctica where he and the team continue their search for the oldest ice record of atmosphere and climate – hopefully stretching back 1.5 million years.
A network of international researchers launches a European collaboration this week ( 14 October 2021). This collaboration will train a new generation of scientists to understand how past climate changes …
New research has revealed that climate changes associated with past episodes of abrupt warming in Greenland occurred synchronously across a region extending from the Arctic to the Southern Hemisphere subtropics. …