A British explorer said Tuesday he would go ahead next year with a pioneering expedition to measure the thickness and density of the rapidly shrinking Arctic Ocean ice cap.

Pen Hadow and two other British explorers will set off in February for a six-month, 1,200-kilometre (750-mile) trek to the North Pole to take samples of ice, snow and air.

The trip had been due to start in February this year but was postponed to allow the expedition's scientific remit to be expanded.

Hadow and his team will manually drill into the ice to extract samples, helping to update the mass of data, hitherto mostly estimated, on the state of the ice cap.

"The only way to get a proper measurement of the snow and ice is to take measurements from the ice surface, or by drilling into it," he told AFP.

"Explorers are the only people who can undertake a survey of this kind."

Hadow -- the first explorer to trek solo and unsupported from Canada to the North Pole -- and his team will send the data via satellite from a specially designed portable computer.

The project will fill the gap in existing measurement studies by satellites and submarines which cannot differentiate between layers of ice and snow.

The expedition's findings will be presented to the crucial United Nations Climate Change Conference in Copenhagen next year aimed at charting a post-Kyoto course to tackle the impact of climate change.

Hadow is currently in intensive training near his home in southwest England, diving into canals, rivers and the sea to simulate the conditions the team will face when they swim between ice floes wearing special immersion suits and dragging their sledges and equipment in the water.

"I haven't been back to the pole for five years and I'm expecting there to be a lot more water than there was last time because the ice is melting," Hadow said.

Current estimates as to how long ice will be a year-round feature around the North Pole range from five to 100 years.

Hadow said: "Sadly, most estimates are tending towards the earlier timeframe."

Ann Daniels, a member of the first all-female teams to trek to the North and South poles, and specialist polar photographer Martin Hartley, who are both British, are the other members of the expedition.