Update your atlas: Southern Ocean recognised as world's fifth ocean by Nat Geo cartographers

 The new ocean has been identified by the National Geography Society, which has been making maps since 1915 and has so far recognised the Atlantic, Pacific, Indian, and Arctic oceans.

The Southern Ocean has also been recognised by the US Board on Geographic Names. (Photo: Nasa/National Geography)

Earth comprises 71 per cent of water and those familiar with geography know that there are four oceans surrounding the landmass. Four? No, now there are five oceans. The National Geography cartographers have now identified the Southern Ocean as the fifth ocean on the planet.

The development comes on the occasion of World Oceans Day which was marked on June 8. The new ocean has been identified by the National Geography Society which has been making maps since 1915 and had so far recognised the Atlantic, Pacific, Indian, and Arctic oceans.

The Southern Ocean has also been recognised by the US Board on Geographic Names as the body of water extending from the coast of Antarctica to the line of latitude at 60 degrees South.

“Anyone who has been there will struggle to explain what's so mesmerising about it, but they'll all agree that the glaciers are bluer, the air colder, the mountains more intimidating, and the landscapes more captivating than anywhere else you can go,” National Geography quoted Seth Sykora-Bodie, a marine scientist at the National Oceanic and Atmospheric Administration (NOAA) as saying.

The development comes on the occasion of World Oceans Day which was marked on June 8. (Photo: National Geography)

While the debate had been long-ranging to identify the vast mass of water surrounding Antarctica as an ocean, the development came when the need to put more focus on the region's peril and the need for conservation became imminent. The boundaries of the ocean were first proposed in 2000, however, not all countries agree on it making it difficult to be recognised by the International Hydrographic Organization (IHO).

The National Geography in a report said that, while other oceans are identified by the region they surround, the Southern Ocean is defined by its current.

Scientists say that the Antarctic Circumpolar Current (ACC) that began circulating following Antarctica's separation from South America, 34 million years ago flows from west to east and is centred around a latitude of 60 degrees south. The latitude now marks the boundary of the Southern Ocean, where the water is colder and less salty. The current pulls water from the Atlantic, Pacific, and Indian Oceans helping the global circulation of air currents.

Antarctica has been facing the brunt of climate change and rapid warming of the planet for decades and scientists are now studying its impact on the Southern Ocean, which is home to a delicate marine ecosystem that includes whales, penguins and seals.