Polar explorer sets off on Arctic survey

Polar explorer Pen Hadow will set off today to begin a 746-mile scientific survey of the floating ice in the Arctic Ocean.

He is to lead a team which will gather data to give scientists a better idea of how long the ice cap will survive.

The Catlin Arctic Survey group, which is leaving from London's Heathrow Airport, expects to reach the North Pole in late May.

The team will travel 746 miles (1,200 km) towards the Pole, dragging a radar unit which will take measurements every four inches (10 cm) of the thickness of the ice and snow.

The explorers hope the new data, which differentiates between the snow and ice, will give a better idea than measurements taken from satellites and submarines of exactly how thick the ice is.

They hope this will enable scientists to project how long the ice cap has left.

There are wildly differing estimates of how much time there will be before the permanent ice cover is lost from the Arctic - ranging from just a few years away to beyond the end of the century.

Mr Hadow, who will be working alongside his fellow adventurers, Ann Daniels and Martin Hartley, said he expected the trip to be a "gruelling" challenge.

The increased melting of the ice cap - some of which melts each summer and re-freezes in the winter - is caused by climate change.

In turn, it can cause more warming as dark-coloured seas absorb more heat than white ice and snow, which reflect it.

Scientific work from the survey, which will send back data via satellites during the 100-day trek, is being undertaken by a number of institutions.

The survey will start from northern Canada around 27 February.

Last week the Prince of Wales, who became patron of the project last year and has been given regular updates, presented the explorers with a pennant for their expedition.

This followed a reception hosted by the prince for the adventurers at Clarence House.