Southern Ocean

The icy ocean around Antarctica

The Southern Ocean circles Antarctica like a ring. Giant icebergs float here — some as big as a whole city! Penguins, seals and whales live in this ocean. They eat tiny shrimp-like creatures called krill.

The Southern Ocean was officially recognised as the fifth ocean by National Geographic in 2021 (south of 60° S). It is defined by the Antarctic Circumpolar Current — the strongest ocean current in the world, which flows around the globe unobstructed and carries 100 times more water than all rivers combined. This ocean plays a key role in Earth's climate, absorbing heat and carbon dioxide. Krill is the base of its food chain; its total mass exceeds that of all humans on Earth. In winter, sea ice covers an area larger than Antarctica itself.

Fun facts

• Iceberg B-15, which broke off in this ocean in 2000, was bigger than the island of Jamaica!
• Fish in the Southern Ocean have 'antifreeze' in their blood — so they don't freeze.
• This ocean has the strongest winds and tallest waves in the world (over 20 m).
• Blue whales come here in summer to eat krill — up to 4 tonnes a day!