The cold facts...

Five years of drilling...base in Antarctica where ice core was extracted

- By Hanna Geissler

BRITISH scientists are about to unravel the secrets of the oldest ice core ever collected from Antarctica as part of a mission that has been decades in the making.

Sections wait in polystyrene chill boxes in a Cambridge laboratory where fans maintain the temperature at -25C.

The ice's arrival at the HQ of the British Antarctic Survey (BAS) was the end of a journey that began with top European scientists selecting a site where the oldest ice at the bottom is 1.5million years old.

After years of radar and topography analysis to find the perfect spot, ice engineers drilled down 2.8km (1.74 miles) over four summers.

Broken up into 4.5m sections, the rods were transported by land, air and sea to Italy then Germany, where they were divided further.

BAS has received a 190-metre section of the time capsule that it will study for chemical elements, particles and isotopes.

These should reveal the atmospheric composition from hundreds of thousands of years ago.

Further analysis will look for microbes, including single-celled algae called marine diatoms.