The wild, storm-swept ocean that encircles Antarctica, where the mightiest current on Earth flows unbroken all the way around the globe.
Area
20,330,000 km²
Ocean basin
Southern
Location
The stormy ocean that rings the frozen south
Average depth
about 3,270 m
Maximum depth
South Sandwich Trench — about 7,236 m
Salinity
~34 ppt
Temperature
Between −2°C and 10°C
Region
Encircling Antarctica
About the Southern Ocean
Recognised as the world’s newest named ocean, the Southern Ocean is defined by the Antarctic Circumpolar Current that flows clockwise around the continent, isolating it and keeping it frozen. Its cold, nutrient-rich waters feed vast swarms of krill that in turn feed whales, seals and penguins. The “Roaring Forties” and “Furious Fifties” make it some of the roughest seas anywhere.
Did you know?
The Antarctic Circumpolar Current here moves more water than all the world’s rivers combined — the largest ocean current on the planet.
Highlights
- Home to the largest current on Earth
- Its krill feed whales, seals and penguins
- Some of the stormiest seas in the world
Photo gallery
Life in the Southern Ocean
Creatures, seabirds and marine plants — including some of the rarest and strangest — that live in these waters.
Creatures of the deep
Orca (killer whale)
The ocean’s top predator: a brilliant, family-living dolphin found in every sea.
Blue whale
The largest animal ever to live — longer than three buses and heavier than 25 elephants.
Giant squid
A deep-ocean giant with eyes the size of dinner plates, almost never seen alive.
Sea angel
A tiny, glass-clear swimming sea slug that flaps wing-like feet through the cold open sea.
Humpback whale
An acrobatic baleen whale famed for breaching clear of the water and singing haunting songs.
Sperm whale
The largest toothed predator alive, diving over 2 km into the dark to hunt giant squid.
Seabirds
Wandering albatross
The longest wingspan of any bird — 3.5 m — gliding the Southern Ocean for years without landing.
Emperor penguin
The tallest penguin, breeding through the Antarctic winter on the open sea ice.
King penguin
A regal sub-Antarctic penguin with glowing golden-orange ear patches.
Arctic tern
The migration champion, flying pole to pole and back — the longest journey of any animal.
South polar skua
A fierce Antarctic pirate that robs other birds and has been seen at the South Pole itself.
Marine plants & algae
Bull kelp
A tough cold-water kelp with a gas-filled float and long, whip-like fronds.
Surface & deep in the Southern Ocean
The sea is warm where the Sun reaches it and cold far below. Flip between the sunlit surface and the deep water to feel the difference — these are typical figures for a ocean.
Sunlit surface
20°C
typical surface temperature
Sun-warmed at the top, the open ocean turns cold and black with depth. Below about 1,000 m it hovers near 3–4°C almost everywhere on Earth, no matter the surface weather.
Recorded range for the Southern Ocean: Between −2°C and 10°C