The deepwater submersibles Mir 1 and Mir 2 (eponymous with the deorbited Russian space station and meaning "peace" or "world") were aptly named—their deployment would stand on par with a space mission in complexity and they certainly caught the "world's" attention. As a nuclear-powered icebreaker crunched through 10 feet (three meters) of August ice at the North Pole, Russian sailors readied the subs for their 2.5-mile (four-kilometer) descent. A hole opened in the ship's wake, and the subs were lowered. At the bottom of the Arctic Ocean, one sub took ground samples, the ostensible purpose of the mission, while the other deposited a titanium capsule containing a Russian flag.

Moscow's 2007 stunt was widely mocked for its ostentatious flouting of diplomatic etiquette but had its intended effect: Other countries were rattled. Canadian Prime Minister Stephen Harper scurried to the Arctic for a sovereignty tour and the Danish science minister released preliminary findings that the North Pole was, in fact, Danish.

Roughly 30 percent of the world's undiscovered oil and gas lurk beneath the melting ice of the Arctic Ocean, and the coastal nations are eager to start drawing lines on the ocean floor. Although three fifths of the world's other three oceans remain high seas, the Arctic will likely hold onto only two small basins designated as the common heritage of humankind. The rest will be parceled off to Norway, Denmark, Russia, Canada and the U.S.—and they're all looking to get rich.

The rules for seabed resource claims stem from the 1982 United Nations Convention on the Law of the Sea (UNCLOS), which allows a 230-mile (370-kilometer) exclusive economic zone off a nation's coast from the low-tide mark. There is one exception: If a continental shelf juts beyond the 200-mile limit, a country's resource claim may be extended. If such a claim is made, a selection of geologists, geophysicists and hydrographers form a committee to evaluate scientific evidence for a nation's elongated shelf.

International treaties, steeped in precedent, do not always mesh with cutting-edge research. Newly returned from riding along on the U.S. Coast Guard's Healy icebreaker as it surveyed the Chukchi Sea northwest of Alaska, Vermont Law School professor Betsy Baker reports a failure of science and law to communicate. "There are a number of terms in the law that are scientifically ambiguous," she says. "How do you define a 'natural prolongation'? And where is the 'foot of a slope'?" In the Arctic, unusually broad shelves and long submarine peninsulas complicate the issue.

"You can read these phrases in different ways, but inside Denmark and Greenland there is good agreement on the resulting formulas," says Flemming Christiansen, technical director of the Geological Survey of Denmark and Greenland. "The commission is looking into claims now from Australia and New Zealand, so their rulings should soon clarify the matter." Most of the 150 convention signatories have a 2009 deadline to make their claims and as many as 50 coastal states could bid for an extension into their neighboring waters.

Out of the five coastal Arctic nations, only the U.S. has never ratified UNCLOS, so it will not be submitting any data to the committee. "A small number of senators resist ceding any sovereignty, afraid the big, bad U.N. is going to divvy up Arctic resources," Baker says. "The irony is, UNCLOS is not a U.N.-run operation."

No one is likely to start investing in expensive resource exploration and extraction if they could be evicted by an international ruling, so the outer shelves will not see development for another 30 years or so, says Baker. The challenges of drilling at three-mile (five-kilometer) depths should not be underestimated either, because existing platforms cannot be used. The ocean floor will have to house recovery complexes and the hydrocarbons may have to be transported to land via pipeline. On an ever-shifting ice pack, only the strongest reinforced rigs or drill ships can survive, and should a spill occur, cleanup would be almost impossible.

There is unexplored oil on the order of 90 billion barrels and 1.67 trillion cubic meters of natural gas, according to a U.S. Geological Survey report, but most of the natural gas lies in the Arctic Ocean closest to Russia. The U.K.-based oil company, BP, PLC, has signed a $17-billion exploration deal with Russia in the hopes of replacing the declining output of its current fields in the North Sea.

Norway's state-owned Statoil has cold-weather expertise with which it hopes to exploit deposits in the Barents Sea, and Canada-based Imperial Oil is among a handful of companies bidding on Canadian claims in the Beaufort Sea. "Seismic will help us determine where we might want to drill, but ultimately we won't know if we've picked the wrong place until we've actually created a well," says Glen McCrimmon, Imperial's geoscience manager for the area.

Aside from already valuable commodities like oil and natural gas, the world's next alternative energy source may lie trapped in the Arctic ice itself. Gas hydrates—a mixture of ice and methane—are found only in high-pressure and cold temperatures. Japan Oil, Gas and Metals National Corporation has bankrolled much of the research into depressurizing deposits a mile under the ocean surface. "People realized, 'Holy cow, this stuff starts bubbling and fizzing when you get it on deck. It's actually flammable. What the heck is it?'" says David Scott, manager of the Northern Resources Development Program for Natural Resources Canada. Gas hydrates are expected to make up a significant portion of the energy mix once existing oil fields dwindle, Scott says.

Even with the best geophysical data, there will still be political questions. The largest feature that demands negotiating is the Lomonosov Ridge, which transects the Arctic Ocean, extending 1,240 miles (2,000 kilometers) from Siberia to Greenland and Canada's Ellesmere Island. "It is possible that the Lomonosov Ridge is attached to all three," says Jorn Skov Nielsen, deputy minister of minerals and petroleum for the Greenland Home Rule Government. "Our geological investigation may find that the North Pole area is part of Greenland's shelf."

Lomonosov was likely a slice of the Siberian shelf that broke off northward during the Cenozoic era when the Eurasian Basin opened up on the Arctic Ocean floor, but its current ties to Russia are disputed. Russia, Canada and Denmark may all end up claiming the ridge—and the rich resources connected to it.

"It's hard to imagine the ridge is continuous for such a long distance," contends Benoit Beauchamp, director of the Arctic Institute of North America in Calgary, Alberta. "But it's not rocket science to find out. Just expensive and hard to access under the ice."