Ocean
Southern Ocean
The Southern Ocean flows all the way around Antarctica, the icy continent at the South Pole. It is the fourth-largest of the five oceans, bigger only than the Arctic Ocean.
Picture credit: Jerzy Strzelecki (CC BY-SA 3.0) · Wikimedia Commons
Where is Southern Ocean?
Continents on its shores: Antarctica.
The story behind it
The Southern Ocean is the youngest ocean on the map. For a long time its water was counted as the southern parts of the Atlantic, Pacific and Indian Oceans. In 2000 the International Hydrographic Organization agreed on the name, and in 2021 National Geographic also began to show it on its maps as the fifth ocean. It covers the sea south of about 60 degrees south. Here flows the Antarctic Circumpolar Current, the strongest current in the world's oceans, which circles the whole continent. Between March and September the sea ice grows from about 2.6 million km² to about 18.8 million km². Huge icebergs drift through the water. Tiny Antarctic krill are among the most plentiful animals on Earth: together they weigh around 500 million tonnes. Seals and whales live here too, and four kinds of penguins breed on Antarctica and the islands close to it.
Find it on the globe
Southern Ocean is there as a name written across its water — tap the water and its card opens. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
Questions children ask
How big is the Southern Ocean?
The Southern Ocean covers about 20.3 million km². That is a little more than twice the size of the United States.
How deep is the Southern Ocean?
Its deepest known point is the Factorian Deep at the southern end of the South Sandwich Trench, about 7 434 m deep. It was found in 2019; older sources give about 7 235 m for the southern end of the trench.
What is the Antarctic Circumpolar Current?
It is a huge ocean current that flows eastwards around Antarctica without ever stopping. It is the strongest and longest current in the world's oceans.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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