Lake Ellsworth Antarctic drilling project called off

An ambitious mission to drill through 3km (1.8 miles) of Antarctic ice to a lake that has been sealed off for thousands of years has been cut short.

The team at Lake Ellsworth decided to call off the mission in the early hours of Christmas Day UK time.

They were unable to join the main borehole with a parallel hole that was to be used to recover drilling water.

The team is now "weatherising" the equipment and it is unclear when they will be able to resume the project.

The £8m ($13m) project, headed by the British Antarctic Survey (Bas), aimed to drill carefully down using near-boiling water to pierce the lake, which has been untouched for as much as half a million years. The hope had been to find hints of life from long ago, or even still surviving today.

A first borehole was drilled and left for 12 hours to create a hot-water cavity. This was to be used to re-circulate drilling water and to balance pressures when the sequestered lake was finally breached.

However, the team were unable to reach the cavity during the course of drilling the second, main borehole - despite trying for over 20 hours.

During that time, drilling water seeped into porous surface layers, and the team used a significant fraction of its fuel. It eventually became clear that the mission could not be concluded.

Audrey Stevens, spokesperson for Bas, said: "We will try again, but it is uncertain when that will be. There will have to be a full report into what's gone wrong."

The team is packing up its equipment and protecting it against the bitter Antarctic winter. It may be more than another season before the team can return to try again.