Geo-Joint: The Southern Ocean

Southern Ocean

Geographic name changes for large expanses of the earth’s surface aren’t all that common. The breakup of the Soviet Union presented such a moment decades ago, and the one we’ll focus on today isn’t breaking news either. It cropped up 15 years ago and isn’t universally accepted yet. But its story is interesting and illustrates the tenacity of established geographic names. Naming conventions of areas on land are created by the people living in those spaces (or their conquerors), but the assignment of names to the vast oceans touching many lands is more a matter of who made the first maps. The locals have always had their names for the big waters, but when they were “discovered” by Europeans who went home to make maps and eventually run most of the world, their names stuck. Even though there is really only one ocean on Earth, it’s a lot easier for humans to understand places when they’re broken up by borders real or imaginary, and given names. The Atlantic got its name from the Greeks even before they had any real idea of its existence. Early reference to the Sea of Atlas pointed to a water body outside the Mediterranean. To them, it was the location of the mythical land of Atlantis. The Pacific was “found” by explorer Vasco Nunez de Balboa, but he called it the Mar del Sur. Six years later Ferdinand Magellan rounded Cape Horn and declared the calmer ocean he sailed into to be “pacifico”, and thus, the Pacific Ocean. The Indian Ocean was obviously named for India, which juts into it and was the focus of much European trading, and the Arctic came from the Greek name for the far northern constellation “Arktos”, meaning “bear”.  It’s the one we call Ursa Major, the big bear.


Now comes yet another division of the world ocean, one that doesn’t have a basin hemmed in by the continents. Among the other oceans it’s smaller than all but the Arctic Ocean, and yet it’s still twice as big as the U.S. This new designation, the Southern Ocean, can be described as the extent of waters reaching from the shores of Antarctica northward to 60 degrees south latitude. That latitude was chosen specifically because it does not cross any land. Why slice off the lowest parts of the Pacific, Atlantic and Indian Oceans? The answer comes from a different and more environmentally based view of the world ocean. Climate, a subject of enormous concern these days, is largely driven by the worldwide conveyer belt of the ocean currents. Heat content and other qualities such as salinity are redistributed across the planet by the slow movement of massive quantities of seawater. Amongst these neverending currents is the Antarctic Circumpolar Current which flows to the east, circling round and round the frozen continent. It is partly driven by the powerful winds called the West Wind Drift, that also ring the waters off Antarctica, unimpeded by any land or mountains. This current is the principal motion of the Southern Ocean. Besides its signature current, this body of water comprises a collection of flora and fauna and water temperatures that make it unique. Ranging from 28 to 50 degrees F, these polar waters require a hardiness in their residents and define an ecosystem distinct from the oceans to their north.


This realization by the scientific community led to a proposal to rename the waters of the far southerly realm. In 2000, the International Hydrographic Organization (IHO) put it to a vote of its then 68 members, all of whom have some ocean coastline. Only 28 of the 68 countries cast ballots, and of those all but Argentina were in favor of a new designation. As for the name, 19 preferred calling it the Southern Ocean, as opposed to the Antarctic Ocean or the South Polar Ocean. Clearly the ballot counts were not overwhelming, and notably the United States did not even support the recognition of a new ocean. Given the relatively weak support for this new concept, map and atlas makers have varied in their willingness to adopt it. The name continues to be absent from many maps 15 years later, but the scientific reasoning for recognizing the Southern Ocean is sound, and in time it will likely appear more universally.

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