Australian and international scientists have identified potential sites to drill for the world’s oldest ice core, beyond a million years, in the Australian Antarctic Territory.

An area at Dome C, 1100 kilometres inland from Australia’s Casey research station and 40 kilometres from the European Concordia station, is most likely to have ice more than a million years old.

The Australian Antarctic Division has taken a leading role in identifying the Dome C site, through survey work to map the region’s ice and bedrock using airborne radar and laser measurements, and glaciological modelling.

This work, with partners including the United States, United Kingdom and France, has found a region where the ice is almost three kilometres thick and has the right conditions to preserve such very old ice.

The ice and the bubbles of air trapped within it, hold information which make it a ‘holy grail’ for ice core scientists to solve a major puzzle in climate science.

The data could reveal why a major change in ice age rhythms occurred around a million years ago, and whether this was connected to changes in carbon dioxide levels.

This will in turn help scientists understand and better predict the long-term future of the world’s climate.