Danes press ahead with claim on ocean tract as Canada tries to shed light on sea vessels that disappeared in the fabled Northwest Passage

Scientists gathering data to underpin a claim by Denmark to a vast Arctic Ocean tract including the North Pole have harvested crucial new information about the seabed.

The country is pressing ahead with its claim to the area – which is thought to hold untapped oil and gas and is likely to offer new shipping lanes as ice recedes.

But there are also rival claims from Russia and Canada.

Denmark and its semi-autonomous dependency Greenland are preparing to file a claim to an area extending north of Greenland and encompassing the pole under the United Nations Convention on the Law of the Sea by November 2014.

Much depends on whether Copenhagen can obtain data showing that the Lomonosov Ridge, an underwater formation stretching 1,800 kilometres across the pole, is an extension of Greenland’s land mass.

“We had a critical gap in the bathymetric (water depth) data and we have covered that now,” Christian Marcussen, the expedition’s chief scientist, said by satellite phone from the Swedish icebreaker Oden at the North Pole.

The 45-day expedition, which set out at the end of July, reached the pole on Wednesday and spent the night there, but left no flag behind on the ice when it resumed its voyage on Thursday.

The 17-man expedition team, travelling with about 50 other scientists from Swedish and other research projects, raised a toast to its success with sparkling wine and posed for a group photo with Danish, Greenlandic and other flags on the drifting ice.

But Mr Marcussen said the custom of posing alongside the flags of all the nationalities that made up the international research team was not meant as a political statement and was only intended to emphasise cooperation.

The Danes’ low-key approach contrasted with a Russian mission five years ago which courted controversy by using a miniature submarine to plant a Russian flag on the seabed at the pole, a move which drew accusations of imperialism.

“We do not go in for that kind of symbolic warfare, we do not think it is very useful,” said Klaus Holm, Denmark’s Arctic ambassador.

“We don’t have a submarine to plant a Danish flag, and we would rather use our resources to gather the data.”

Denmark has played down the idea that the race to claim the pole could trigger conflict. It says diplomacy will prevail, and that states with rival claims are committed to negotiating through established channels.

“There might be overlapping legitimate claims which all have scientific backing,” Mr Holm said.

This year’s Danish expedition is the third in a series of voyages that began in 2007 to gather data to support a claim to the Commission on the Limits of the Continental Shelf (CLCS), which assesses the scientific validity of such claims.

Denmark has identified five potential claim areas off Greenland and the Faroe Islands – both parts of the Kingdom of Denmark – and has already submitted claims for areas north and south of the Faroes and for two areas south of Greenland.

The fifth area, probably the most sensitive part of any future claim, is roughly 150,000 square kilometres extending north from Greenland and encompassing the North Pole.

Despite a record thaw of sea ice in the Arctic, the expedition vessel has had to break through thick ice to gather seismic and sea depth data.

“In patches measurements were simply impossible and cancelled ... Equipment has been damaged by the ice so it has not been a piece of cake,” said Martin Breum, a journalist and author travelling with the mission.

Once claims are submitted, it is likely to take years or even decades for the CLCS to issue a report, and only after that could negotiations between states begin, Mr Holm said.

The Oden left the pole on Thursday afternoon.

“We are now struggling through heavy ice towards Siberia,” Mr Breum said.