In 2007, two Russian minisubs planted a titanium flag at the North Pole at a depth of 4,300 meters below the surface of the Arctic Ocean, setting off a rush to stake out claims to the seabed.

The Arctic Ocean (Figure 1), the smallest of the world's five major oceans, is about 4000km (2500 miles) long and 2400km (1500 miles) wide, about the size of the continental USA. It lies entirely ...