Last week the Russians dropped placed a Russian flag on the seabed below the North Pole. This was a stunt - drawing attention to a significant technological capability - but in itself without legal implications.
The world is now aware, however, that a contest is on for territorial and seabed rights in the Arctic. Much of the argument revolves around the underwater Lomonosov Ridge. Here is a map of the ridge from Wikipedia. You can see the long line of the ridge extending across the top of the world from the Russian to the Canadian/Greenland continental shelves:
Here's a second map from a BBC News story, showing the political boundaries:
The BBC story notes the following:
1) North Pole: Russia leaves its flag on the seabed, 4,000m (13,100ft) beneath the surface, as part of its claims for oil and gas reserves
2) Lomonosov Ridge: Russia argues that this underwater feature is an extension of its continental territory and is looking for evidence
3) 200-nautical mile (370km) line: Shows how far countries' agreed economic area extends beyond their coastline. Often set from outlying islands
4) Russian-claimed territory: The bid to claim a vast area is being closely watched by other countries. Some could follow suit
Since the 1920s, some countries have claimed rights over sectors of the Arctic between their land masses and the North Pole. Canada was the first to do so in 1925 (Wikipedia: "Northern Canada"):
Since 1925, Canada has claimed the portion of the Arctic between 60°W and 141°W longitude, extending all the way north to the North Pole: all islands in this region are Canadian territory and the territorial waters claimed by Canada surround these islands. Views of territorial claims in this region are complicated by disagreements on legal principles. Canada and the USSR/Russia have long claimed that their territory extends according to the sector principle to the North Pole. The United States does not accept the sector principle and does not make a sector claim based on its Alaskan arctic coast. Claims that undersea geographic features are extensions of a country's continental shelf are also used to support claims; for example the Denmark/Greenland claim on territory to the North Pole, some of which is disputed by Canada. Foreign ships, both civilian and military are allowed the right of innocent passage through the territorial waters of a littoral state subject to conditions in the United Nations Convention on the Law of the Sea. The right of innocent passage is not allowed however, in internal waters, which are enclosed bodies of water or waters landward of a chain of islands. Disagreements about the sector principle or extension of territory to the North Pole and to the definition of internal waters in the arctic lie behind differences on territorial claims in the Arctic. This claim is recognized by most countries with some exceptions, including the United States; Denmark, Russia, and Norway have made claims similar to those of Canada in the Arctic and are opposed by the European Union and the US.
This is especially important with the Northwest Passage. Canada asserts control of this passage as part of the Canadian Internal Waters because it is within 20 km of Canadian islands; the US claims that it is in international waters. Today ice and freezing temperatures makes this a minor issue, but global warming may make the passage more accessible to shipping, something that concerns the Canadian government and inhabitants of the environmentally sensitive region.
I assume the BBC map shows Russian territorial claims based on this sectoral principle, in addition to claims based on the geology of the Lomonosov Ridge. The map could - but doesn't - show a similar Canadian claim.
Newer claims, including Russia's Lomonosov Ridge claim, are based on provisions of the U.N. Convention on the Law of the Sea. This story from Geotimes: Cold wars: Russia claims Arctic land (Carolyn Gramling, August 1) provides a good background - going beyond the content of most recent stories from newspapers. Gramling explains the importance of geological, as well as topographical, mapping of the seabed:
The Law of the Sea defines the outer limits of a country’s shelf as the “natural” extension of the land mass either to the outer edge of the continental margin or to 320 kilometers from the coast. Whether the Lomonosov Ridge can be considered a geological extension of the Siberian shelf is unclear, however. “It becomes a matter of definition,” says Jim Cochran, a marine geophysicist at Lamont-Doherty Earth Observatory in Palisades, N.Y. The ridge is a narrow band of continental crust stretching between Greenland and Siberia — and passing through the geographic North Pole — that rises above deep ocean basins on either side, and runs parallel to the nearby Gakkel Ridge, a mid-ocean ridge spreading center.
The Lomonosov Ridge’s complicated history adds to the scientific uncertainty. In the early Tertiary (50 million years ago) the ridge was ripped away from the outer part of the continental margin of Eurasia, north of Scandinavia and Russia, and a new ocean basin formed between the ridge and the shelf, Cochran says. On the Alaskan side, the basin between the ridge and the shelf is older, dating to the Cretaceous period (120 million years ago), he says.
At question is exactly how the Lomonosov Ridge and the Gakkel Ridge intersect with the Siberian part of the shelf. A number of expeditions over the past decade have studied the structure of the ridge to try to understand that intersection. From 1995 to 1999, the Scientific Ice Expeditions (SCICEX) program, in which Cochran participated, used a Navy submarine to collect a variety of information on the geology of the Arctic. SCICEX provided a closer look at the variation in geologic structure of the Lomonosov Ridge. Other seismic work, by a team of German scientists, found that the ridge becomes deeper as it approaches Siberia, with a lot of faulting in the deeper sediments. Those faults suggest that even if the ridge is currently attached to the Siberian shelf, prior to about 10 million years ago it may not have been part of the shelf at all, or was at least partially disconnected.
Based on this data, some scientists hypothesize that the Lomonosov Ridge came from a different part of the Eurasian shelf originally, and is actually a sliver of shelf that long ago became cut off from its earlier location by faulting and rifting. The piece of shelf may then have slid for several hundred kilometers along a transform fault until it reached its current location on the Siberian shelf.
“That’s where definitions come in,” Cochran says. The question, he says, is whether a piece of land that happens to be currently alongside a country’s shelf can be considered part of that shelf. “There is probably no oceanic crust between the ridge and the Russian shelf, but if something slides along your margin, is it part of the shelf or not?”