AILSA CHANG, HOST:
Mary Louise, can you name all of the Earth's oceans?
MARY LOUISE KELLY, HOST:
Easy. There are four - the Pacific, Atlantic, Indian, and Arctic.
CHANG: Nah, not so fast. National Geographic is adding a fifth to their maps.
ALEX TAIT: National Geographic has been making maps and atlases and globes for over a hundred years. And this is the first time we've ever changed our set of oceans, official oceans.
CHANG: That is Alex Tait from the National Geographic Society. This week, the society recognized the waters encircling Antarctica as the Southern Ocean, but those who study the area were way ahead of the society.
CASSANDRA BROOKS: To be completely honest with you, I was rather surprised because I had always thought of the Southern Ocean as its own ocean. I think most of the scientists who work down there really understand how the Southern Ocean is its own thing.
KELLY: Cassandra Brooks is an assistant professor at the University of Colorado Boulder. She says, unlike the other oceans that are primarily defined by the land areas that surround them, the Southern Ocean is different.
CHANG: It's defined by a powerful set of currents called the Antarctic Circumpolar Current, which is an ocean current that flows clockwise around the continent. It's critical because...
BROOKS: It's driving currents all over the world, regulating our currents as well. And so it really is this amazing - I don't know. I almost think about it as, like, the lungs or the heart. Right? Like, it's pumping. It's pumping water (laughter) - right? - throughout the world's ocean.
KELLY: Both Tait and Brooks hope this new recognition will create more awareness.
BROOKS: Antarctica's so far away that most people don't think about it on a day-to-day basis. They're not seeing how important it is to, literally, all of our survival. Right? So I just - I hope it can take this obscure place and bring it to people and that they will be excited to learn more about it.
KELLY: Guess it's time to officially update all those maps.
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