Summary: | A NEW OCEAN has appeared on the maps of the National Geographic Society, an American research and conservation organisation. The Southern Ocean, which encircles Antarctica, will henceforth be given the same status, and typeface, as the Arctic, Atlantic, Indian and Pacific Oceans. But of course the Southern Ocean is not really new. Not only has the body of water been there for around 30m years, since Antarctica and South America moved apart, but what to call it has been mulled and contested by others before. So how many oceans are there? And how is that decided? A daily email with the best of our journalism All of Earth’s oceans are part of one interconnected system. Mapmakers divide it into different zones, including oceans, which also contain smaller seas. Oceans are usually bordered by whole continents whereas seas are typically surrounded by smaller bits of land. But where two bodies of water converge scientists must look at the conditions in the water to decide their boundaries. Bodies of water often have multiple names. The Southern Ocean is sometimes called the Antarctic Ocean. Sometimes these names reflect competing political claims. For instance, the one between Japan and the Koreas is known as the Sea of Japan in Japan, the East Sea in South Korea and the Korean East Sea in North Korea. Most governments have departments given the task of surveying, mapping and naming oceanographic features but the arbiter of such issues is the International Hydrographic Organisation (IHO), to which 94 countries belong. (June 21st is also the IHO’s World Hydrography Day.) The definition adopted by the National Geographic Society is that the Southern Ocean includes most of the waters that surround Antarctica to a latitude of 60° south, excluding the Drake Passage and Scotia Sea. Also called the “60th parallel south”, this cartographic line roughly corresponds with the path of the Antarctic Circumpolar Current, which swirls water clockwise from west to... |