The United States has extended its claims on the sea floor by an area twice the size of California, securing rights to potentially resource-rich areas.

The ‘Extended Continental Shelf’ covers about 1 million square kilometres (386,100 square miles), predominantly in the Arctic and Bering Sea, an area of increasing strategic importance where Canada and Russia also have claims.

Law of the Sea

The 1982 United Nations Convention on the Law of the Sea, which the US never ratified, governs maritime zones around countries. Under the law, countries have the right to any resources in the sea or seabed floor within their so-called exclusive economic zones, which can stretch up to 200 nautical miles off the coast.

But beyond that, they can claim economic rights to resources on or below the seabed floor where their continental shelf extends, although not within the water column. The seas above also remain international waters.

Russia, Denmark and Canada have waited years for their overlapping Arctic seabed claims to be reviewed by the Commission on the Limits of the Continental Shelf (CLCS), a UN supported group, with Russia the first to receive a ruling earlier this year.

The decision to unilaterally delineate its continental shelf boundary, rather than to ratify UNCLOS and then submit a claim through the commission, may raise the ire of other countries, said Rebecca Pincus, director of the Polar Institute at the Wilson Center in Washington.

“I think a lot of other countries around the world are going to have thoughts about how the US has done this,” she said. It also may reduce the likelihood of the US ever ratifying the law since a major reason for doing so would have been to make a CLCS claim, she said.

Canada’s reaction

Grantly Franklin, spokesman for Global Affairs Canada, said in an email that Canada expects to follow the process set out in a United Nations treaty despite the fact the U.S. hasn’t ratified the Convention on the Law of the Sea.

“Canada and the U.S. are in frequent communication with regards to the continental shelf in the Arctic and have expressed their commitment along with other Arctic states to the orderly settlement of overlapping claims,” Franklin wrote.

“It’s stuff that we’ve always suspected they were going to do,” said Rob Huebert, a professor at the University of Calgary’s Centre for Military, Security and Strategic Studies. “The Americans have been very careful not to have any overlap with the Russians but they have overlap with us.”

A large part of the overlap concerns how the border should be drawn. Canada wants it extended directly north from the 141st meridian while the U.S. says it should be drawn at a 90-degree angle from the shoreline.

“Every single one of our Arctic neighbours has an overlap with us,” said Huebert.

He said growing geopolitical tension around the world isn’t going to make drawing those lines on the waves any easier.

This story was compiled from extracts in Mining.com, Bloomberg, and National Observer.

The ‘Announcement of U.S. Extended Continental Shelf Outer Limits’ from the US Department of State can be read here.