Icebreaker sets mark for earliest Northwest Passage transit.

NUUK, Greenland — After 24 days at sea and a journey spanning more than 6,214 miles, the Finnish icebreaker MSV Nordica has set a new record for the earliest transit of the fabled Northwest Passage.

The once-forbidding route through the Arctic, linking the Pacific and the Atlantic oceans, has been opening up sooner and for a longer period each summer due to climate change. Sea ice that foiled famous explorers and blocked the passage to all but the hardiest ships has slowly been melting away in one of the most visible effects of man-made global warming.

Records kept by Canada’s Department of Fisheries and Oceans show that the previous earliest passage of the season happened in 2008, when the Canadian Coast Guard ship Louis L. St-Laurent left St. John’s in Newfoundland on July 5 and arrived in the Beaufort Sea off Point Barrow on July 30.

The Nordica, with a team of researchers and Associated Press journalists on board, completed a longer transit in less time — albeit in the opposite direction — setting off from Vancouver on July 5 and reaching Nuuk, the capital of Greenland, on July 29.

While the icebreaker encountered Chinese cargo vessels, Alaskan fishing boats and a German cruise ship in the Pacific, upon entering the Canadian Archipelago, the Nordica traveled alone. Radar indicated the presence of the U.S. Coast Guard cutter Sherman near Point Barrow; along the coast an occasional collection of houses revealed evidence of human settlement in the far north.

For the most part, the ship’s only companions were Arctic sea birds, seals and the occasional whale, until two-thirds of the way through the voyage, as Nordica was plowing through sea ice in Victoria Strait, a crew member sighted a polar bear.

These animals have come to symbolize the threat posed to Arctic wildlife by climate change because the sea ice they depend on for hunting is disappearing a bit more each year. Scientists predict the Northwest Passage will be largely ice free in the summer by 2050 if current levels of warming continue.

For now, the passage remains a challenge for conventional ships and efforts are being made to prevent frozen waterways that the local Inuit population depends on for travel from being opened up.

David Goldman The Associated Press Canadian coast guard Capt. Victor Gronmyr looks out July 22 over the ice covering the Victoria Strait as the Finnish icebreaker MSV Nordica traverses the Northwest Passage through the Canadian Archipelago.