Ice core clue to Earth’s evolution

In an attempt to reveal how the planet has evolved, polar scientists have successfully drilled a 2,000-year-old ice core in the heart of Antarctica. Approximately two tonnes of ice core sections from the Aurora Basin, which lies 310 miles inland of Australia’s Casey station, is now being distributed to Australian and international ice core laboratories where it will undergo analysis. Scientists are searching for atmospheric gases, particles and other chemical elements that were trapped in snow as it fell and compacted to form ice. “Using a variety of scientific tests on each core, we’ll be able to obtain information about the temperature under which the ice formed, storm events, solar and volcanic activity, sea ice extent, and concentrations of different atmospheric gases over time,” said project leader, Mark Curran, Australian Antarctic Division glaciologist. “There are only a handful of records with comparable resolution that extend to 2,000 years from the whole of Antarctica, and this is only the second one from this sector of East Antarctica.” The international team, which included researchers from Australia, China, France, Denmark, Germany and the US, worked in temperatures of -30°C to extract the main 303m long ice core, which will provide annual climate records for the last 2,000 years. Two smaller cores of 116m and 103m were also removed, spanning the past 800 to 1,000 years. The project will give experts access to some of the most detailed records yet of past climate change, and should help scientists locate suitable sites for more ambitious expeditions to collect the ‘holy grail’ –a one million-year-old ice core in the future. “Such an ice core would help us understand what caused a dramatic shift in the frequency of ice ages about 800,000 years ago, and further understand the role of carbon dioxide in climate change,” said Curran.