The Arctic Ocean is the no. 5th contiguous open water surface on earth. It has a huge, 5,427,000 square mile (14,056,000 square km) area and 3,953 square feet (1,205 square meters) average depth. The Arctic Ocean’s greatest known depth is 18,456 feet (5,625 meters), which can be found at 77 45 N.
The Northwest Passage (the US and Canada) and Northern Sea Route (Norway and Russia) are two important seasonal waterways. In recent years the polar ice pack has receded in the summer, enabling increased navigation and raising future sovereignty and shipping disputes among the six countries bordering the Arctic Ocean (Canada, Denmark (Greenland), Iceland, Norway, Russia, US).
Oceans and shallow seas cover more than two-thirds of the planet, to an average depth of 2½ miles / 3.8 km. The Pacific Ocean alone covers nearly half the globe. The oceans contain about 320 million cubic miles / 1,330 million cubic km of salty seawater, accounting for 97 percent of the water on Earth. Most of this water forms a dark, cold realm deep below the surface, where life is scarce, but the shallow, sunlit waters of coastal seas are some of the world’s richest wildlife habitats.