U.S. expedition mapping the Arctic

The U.S. Coast Guard icebreaker Healy and a group of 20 scientists have embarked on a four-week cruise that will help shape the future of U.S. efforts to claim its share of mineral and oil wealth beneath the Arctic Ocean.

The cruise, which left Barrow, Alaska, on Friday, is the fourth voyage in the past four years to the Chukchi Cap, north of the Bering Strait. The cap is part of a plateau and ridge complex that juts like a thumb from the Alaskan and Siberian continental shelves into one of the Arctic Ocean's deep basins.

Measurements taken on this cruise are of keen scientific and geopolitical interest.

"Mapping is the fundamental first step in any sort of exploration," said Larry Mayer, the chief scientist for the cruise and a researcher at the Joint Hydrographic Center at the University of New Hampshire in Durham. "Like Lewis and Clark, we're providing a geospatial framework for everything else we need to know" about the least understood ocean on the planet.

But the maps Lewis and Clark generated also provided a foundation for political and economic expansion into the regions they explored. And for the U.S. government, which is underwriting the cruise, that is a headline reason for conducting the survey.

The Arctic mapping is aimed at specific aspects of the cap that serve as geophysical baselines the U.S. could use to press future claims to extend its jurisdiction off Alaska beyond the 200-mile limit.

If the U.S. does eventually press such claims it will be a latecomer to an already fractious club meeting.

Earlier this month, Russia placed a small flag on the sea floor at the North Pole to press its claim that it owns most of the Arctic sea floor. It bases its claim, first set out formally in 2001, on a stretch of undersea ridge that runs from off Siberia to just off the northern end of Greenland. It claims that the ridge actually split off from the Eurasian continent and so remains part of Russia's continental shelf. Canada and Denmark make similar arguments using the same undersea feature, the Lomonosov Ridge.

In all, eight countries so far, including Russia, are asking to extend their jurisdiction over various patches of global oceans under the 1982 U.N. Law of the Sea Convention treaty, which took force in 1994. The U.S. Senate has not ratified the treaty, despite years of urging from Presidents Clinton and Bush, so the U.S. doesn't have a seat at the table as critical decisions are made on how to divvy up the ocean bottom, said a senior U.S. State Department official.

And the U.S. has fallen a decade or more behind other countries in conducting the survey work — especially in regions like the Arctic where there are clear competing claims, the official said.

Countries trying to lock up large portions of the Arctic seafloor are not aiming to build something next week or next year, the official added. Instead, they argue that "this is part of our patrimony that we want to stake out to make sure we have control over it in the future," the official said.

In addition to the potential economic payoffs from gas and oil exploration, there are clear scientific gains to be made. On one cruise, for instance, the Healy uncovered a seamount (now the Healy Seamount) that no one had detected before — even though it vaulted from 4,000 feet deep to less than 900 feet below the surface. In other oceans, sea mounts are biologically rich and serve as feeding stations for migratory fish.

In addition, Mayer says, cruise scientists hope to map a series of pockmarks on the ocean floor that suggest gas is slowly venting from the sediment there.

Previous cruises have uncovered unique marine organisms that use vented gas for food. Researchers also will be deploying buoys to track sea ice and record the region's underwater sound environment.