The US Coast Guard icebreaker Healy and a group of 20 scientists have embarked on a four-week cruise that will help shape the future of US 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 last 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," notes 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 US government, which is underwriting the cruise, that is a headline reason for conducting the survey. The National Oceanic and Atmospheric Administration has been conducting similar surveys over the past several years around the Marianas Islands, the Gulfs of Alaska and Mexico, and off New England, notes Capt. Steven Barnum, who heads the agency's Office of Coastal Survey.
But the Arctic Ocean has been receiving particular attention because it lacks the detailed undersea maps that other areas enjoy. The maps are aimed at specific aspects of the cap that serve as geophysical baselines the US could use to press future claims to extend its jurisdiction off Alaska beyond the 200-mile limit.
If the US does eventually press such claims it will be a latecomer to an already fractious club meeting.
Earlier this month, Russia placed a small Russian flag on the seafloor at the North Pole to press its claim that it owns most of the Arctic seafloor. 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, called 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 UN Law of the Sea Convention treaty, which took force in 1994. The US Senate has not ratified the treaty, despite years of urging from Presidents Clinton and Bush. So it doesn't have a seat at the table as critical decisions are made on how to divvy up the ocean bottom, explains a senior US State Department official. And the US 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 explains.
Countries trying to lock up large portions of the Arctic seafloor are not aiming to build something next week or next year, the official adds. 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 says.
Technologically, that future is likely to hold new approaches to deep-sea drilling that enables energy companies to work in such a hostile environment. And it implies an environment that is expected to grow somewhat less hostile with time. For instance, Aug. 17, researchers reported the extent of Arctic Ocean sea ice this summer is at its lowest point since satellites started to keep track of it in the 1970s – with another month remaining in the melt season. If current melt rates continue, summer sea ice could vanish by 2030, instead of by the mid to late part of the century. Scientists say they trace the reduction to global warming and some level of natural variation.
This is the context under which geophysicists have entered the fray. Under the treaty, countries have a small menu of benchmarks they can choose from to make a bid for extending their jurisdictions beyond 200 miles. They can use the foot of the slope leading from the top of the continental shelf to the deep-seafloor. They can use an imaginary line along the slope at a depth of 8,250 feet. Or they can pick a spot where the depth of the muck on the deep-sea bottom is 1 percent of the distance between that point and the foot of the continental shelf. Countries can pick the approach that gives them the most leverage.
That's where the geophysicists enter the fray, using high-resolution sonar to map the shelf and nearby floor and other tools to gauge the depth of sea-bottom sediment.
And there are clear scientific gains to be made as well. 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. Researchers wonder if the same holds true for seamounts in frigid Arctic waters.
In addition, Dr. 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 underwater sound environment in the region.