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Scientists drill 2,000-year-old ice core in Antarctic’s heart

AFP-JIJI

Polar scientists said Thursday they had successfully drilled a 2,000-year-old ice core in the heart of Antarctica in a bid to retrieve a frozen record of how the planet’s climate has evolved.

The Aurora Basin North project involves scientists from Australia, China, France, Denmark, Germany and the United States. They hope it will also advance the search for the scientific holy grail of the million-year-old ice core.

The five-week expedition, in a hostile area that harbors some of the deepest ice on the frozen continent, over 3 km thick, will give experts access to some of the most detailed records yet of past climate in the vast region.

About 2 tons of ice-core sections that were drilled at Aurora Basin, 500 km inland of Australia’s Casey Station, are now being distributed to Australian and international ice-core laboratories. The labs will conduct an analysis of atmospheric gases, particles and other chemical elements that were trapped in snow as it fell and compacted to form ice.

Australian Antarctic Division glaciologist and project leader Mark Curran said it will help fill a gap in the scientific community’s knowledge of climate records. “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 the concentration of different atmospheric gases over time,” he said.

The team, working in temperatures of minus 30 degrees Celsius, used a Danish Hans Tausen drill to extract the main 303-meter-long ice core, which will provide annual climate records for the past 2,000 years. Two smaller drills were used to take out 116-meter and 103-meter cores spanning the past 800 to 1,000 years.

“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,” Curran said.

Data collected during the drill should help scientists locate a suitable site for a more ambitious, future expedition to collect a 1-million-year-old ice core.

“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.