Lack of permanent Arctic ice surprises explorers

David Ljunggren, Reuters 17 Apr 09;

OTTAWA (Reuters) - The head of a British team walking to the North Pole on a mission to gauge how fast Arctic ice sheets are melting said on Friday he was surprised by how little permanent ice he had found so far.

Pen Hadow and two other adventurers set off in early March on a 1,000-km (620-mile) trek from Canada's Arctic to the North Pole. The team was set down in an area where scientists had been sure there would be permanent multiyear ice.

But so far, the average depth of the ice has been just under 1.8 meters (6 feet), suggesting they are finding predominantly new first-year ice that is likely to melt in summer months.

"My surprise is guided by the scientific community's expectations of what the ice should be here," Hadow told Reuters via satellite phone from about 620 km from the North Pole.

"In the opening section of the (journey), most would have anticipated multiyear ice, ice certainly more than 2 meters and really more than 3.5 meters thick."

The team said in a statement that the findings pointed to an ever-smaller summer ice covering around the Pole this year.

One top polar expert said last month the Arctic is warming so quickly that the summer sea ice cover could vanish as early as 2013, decades earlier than some had predicted.

The Arctic is warming at twice the rate of the rest of the world and the sea ice cover shrank to a record low in 2007 before growing slightly in 2008.

Scientists link higher Arctic temperatures to the greenhouse gas emissions blamed for global warming.

Hadow, saying he did not know what had caused the ice to be so thin, said possible reasons included warmer air and ocean temperatures as well as stronger winds that were blowing the ice out of position.

He also found that the snow cover on top of the ice was much thinner than the 35 cm (14 inches) he had expected.

"Thinner ice has less snow on it so the two measures support each other. It's not as though we have some weird anomaly going on," he said.

Summer ice tends to be concentrated around the North Pole while much of the thicker multiyear ice is clumped around the islands of Canada's Arctic archipelago.

Chip Cunliffe, the team's head of operations, declined in a separate interview to say what he thought might have caused the ice to be thinner than expected, saying he would let scientists analyze the data.

The team spends four hours a day drilling into the ice to take measurements. Hadow has a manual drill that can go down 5.2 meters and so far has hit ice that deep just four times.

"If we'd had more multiyear ice there it's more likely that he would have got (that deep) on more than just four occasions," Cunliffe said.

The team had planned to use an experimental portable radar set to measure the ice more accurately but had to resort to the drill after intense cold knocked out the radar's power supply. Hadow said he was optimistic it could be repaired soon.

The three explorers, who have covered about 380 km so far, are due to be picked up in late May.

The main sponsor for the 3 million pound ($5.4 million) expedition is British insurer Catlin

($1=0.56 pounds)

(Reporting by David Ljunggren; editing by Rob Wilson)