Coastline Length: <\/strong>45,390 km (28,200 mi)<\/li><\/ul>\n\n\n\nThe Arctic ocean covers an area of 5.4 million square miles, making it the smallest of Earth\u2019s oceans. Because around a third of the ocean is permanently covered in ice, it is relatively unexplored. The ocean is also in continuous darkness from November to February and in continuous light from May to August.<\/p>\n\n\n\n
The Arctic ocean has a large depression at its center with an average depth of over 4,000 meters. This basin is divided by a long submarine ridge, the Lomonosov Ridge, which creates two sub-basins. The Amerasia Basin is on the side facing North America while the Eurasian Basin faces Europe and Asia.<\/p>\n\n\n\n
Around the edges of the Arctic Ocean lie the continental shelves of North America and Eurasia. On these shelves lie a large number of islands many of which are linked by ice during winter months.<\/p>\n\n\n\n
The permanent ice cap is primarily made up of compressed pack ice with a thickness of up to 10 meters. Strong currents are continually moving this ice causing the formation of cracks and open pools. However since the 1950s this ice cap has thinned by as much as 40%. The breaking off of large bodies of ice from the main ice sheet has also increased.<\/p>\n\n\n\n
The Arctic ocean is home to a large variety of birds, fish, and mammals. Polar bears are born on land but spend most of their lives on the sea ice where they hunt seals and even some whale species. Polar bears often lie in wait at holes in the ice waiting for these mammals to surface for air. Walruses also make their homes in the Arctic where they survive by eating shrimp, crabs, and molluscs. To protect against the cold water they, like other marine mammals, have a thick layer of fat (also known as blubber). The Arctic is home to a large number of different whale species including Beluga, Bowhead, Narwhals, and Killer whales. Fish found in these waters include Atlantic Cod, Haddock, Mackerel, and Salmon. Recent changes in Earth\u2019s climate pose a considerable threat to many of these animals which are in danger of losing their habitats.<\/p>\n\n\n\n
The Atlantic Ocean<\/h3>\n\n\n\n
The Atlantic Ocean, as viewed from the Cliffs of Moher in Country Clare, Ireland.<\/em><\/strong><\/figcaption><\/figure><\/div>\n\n\n