The World's Fifth Ocean Is Officially On The Map Thanks To National Geographic


Maddy Chapman

Maddy is a Editor and Writer at IFLScience, with a degree in biochemistry from the University of York.

Editor & Writer

Antarctica map

The Southern Ocean, surrounding Antarctica, has been officially recognized as one of the world's five oceans. Image credit: deer boy/

It’s official! National Geographic has now recognized the Southern Ocean as the world’s fifth ocean. The announcement on June 8 – just in time for World Ocean Day – marks the end of decades of dispute over the body of water surrounding Antarctica and will, quite literally, put the Southern Ocean on the map.

Until now, only four oceans have been officially recognized   the Atlantic, Pacific, Indian, and Arctic Oceans. These are defined by continent, making the Southern Ocean somewhat of an anomaly – it is defined, instead, by current. The Antarctic Circumpolar Current (ACC) flows from east to west around Antarctica and was established 34 million years ago. It is centered at a latitude of 60 degrees south (the northern boundary of the Southern Ocean). The current creates an invisible ring around Antarctica, in which waters are colder and less salty than those to the north. However, it has long been debated by geographers whether the oceanic ring was merely an extension of the Pacific, Atlantic, and Indian Oceans, or whether it was an ocean in its own right.


The U.S. Board of Geographic Names recognized the Southern Ocean and approved its name in 1999. The proposed boundaries were presented to the International Hydrographic Organization (IHO) in 2000, but are still yet to be agreed on some 21 years later. Meanwhile, the National Oceanic and Atmospheric Administration (NOAA) has only recognized the Southern Ocean since February this year.

“The Southern Ocean has long been recognized by scientists, but because there was never agreement internationally, we never officially recognized it,” National Geographic Society Geographer Alex Tait told the National Geographic. 

The National Geographic Society has been making maps for over a century and has employed geographers to oversee all changes made to every map published since the 1970s. They generally follow the IHO when it comes to marine nomenclature, hence this latest acknowledgment of the Southern Ocean marks a break from that tradition. It is hoped that the recognition will raise awareness for the new ocean and its ecologically distinct ecosystem, and also promote much-needed conservation efforts – industrial fishing has been an issue in the Southern Ocean for years.

As for the future of the world’s "newest" ocean, that remains uncertain. It is currently being studied what effect climate change may have: Antarctica’s waters are warming and its ice sheets are melting. How this affects the fledgling ocean only time will tell – we can only hope that its formative years run smooth and that the Southern Ocean can make some waves.




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