Canadian and U.S. Coast Guard cutters are returning to the Arctic on science missions this summer, but this time they'll be mapping the sea floor in a section of the Beaufort Sea claimed by both countries. CBC News reports the teams will be exploring the outer edge of the continental shelf in preparation for submissions to the United Nations defending Arctic claims.

From the CBC:

The two research vessels have worked together to map the Arctic seabed for three years, but never in the pie-shaped, 21,000-square-kilometer disputed area that is approximately the size of Lake Ontario.

The U.S. says the sea border should go out at a 90-degree angle from the land at the Canada-[Alaska] border, but Canada's opinion is that it should continue to follow the 141st meridian, which is what the land border follows.

Canadian foreign affairs spokeswoman Alison Saunders told the CBC that her boss, Foreign Affairs Minister Lawrence Cannon, and U.S. Secretary of State Hilary Clinton have agreed in principle let experts from each country share their findings before the 2013 UN deadline. The disputed part of the Beaufort Sea may have extensive energy-development potential, experts say.