For decades, elementary school students have learned that there are seven continents and four oceans: the Pacific, the Atlantic, the Indian, and the Arctic oceans. But this month, National Geographic announced there is a fifth ocean around Antarctica. It's called the Southern Ocean. Beyond having to update countless atlases and globes, the designation has big implications for our understanding of climate change.
“There hasn't been full agreement internationally on this, even though it's well recognized as a distinct region,” says Alex Tait, geographer and cartographer for the National Geographic Society. “We felt it was important to do it now because we see how important this region is for its role in global climate, and for its distinctness as a region of animals and fish life. It's a very important area ecologically and worthy of conservation and protection.”
Tait says despite oceans having different names, they’re technically one body. “There really is just one world ocean. They're all interconnected, and currents and different gyres do move water around between all the oceans. So there is one interconnected world ocean, but it is divided into regions.”
He adds, “Some of the regions are divided by large land masses and other regions, like the Southern Ocean, are divided by ecological conditions, such as ocean currents, and the temperature and salinity differences for that area.”
Tait says that oceans are key in climate change due to temperature changes and their ability to store carbon.