In May 2008, the Alfred-Wegener-Institute for Polar and Oceanic Research and the University of Bern published this image of the so far oldest antarctic ice drill core from a depth of 114m. It shows a thin section of the ice core, photographed in polarised light to reveal the edges of ice crystals and enclosed gas bubbles.

The ice core stores information on a time span of more than 8 glacial periods. From the enclosed air, the researchers can measure the content of carbon dioxide and methane. The examination has shown that the concentration of carbon dioxide in our atmosphere is today more than 28 per cent higher than ever before during the last 800,000 years.

source: www.idw-online.de