Hideaki Motoyama with the ice sample in Tokyo. (Reuters)

Tokyo, April 18 (Reuters): A million-year-old ice sample drilled from 3 km under the Antarctic and unveiled in Tokyo today could yield vital clues on climate change, Japanese scientists said.

Researchers, showing off the cylindrical samples of what they said was the oldest ice ever to be retrieved, said studying air trapped inside “core” samples taken from various depths underground could also help predict how the Earth’s weather patterns will change in the future.

“The ice core is made up of snow that fell in the distant past,” said project leader Hideaki Motoyama of the National Institute of Polar Research, dressed snugly in a parka after unveiling the gleaming ice in a room kept at minus 20 degrees Celsius .

“You can use it to examine changes in temperature, levels of carbon dioxide and methane over time,” he said.

Researchers at the Dome Fuji base in the eastern Antarctic spent more than two years on the delicate operation of drilling into the ice sheet, coming up with the million-year-old samples in January and shipping them to Japan on an icebreaker.