Generally considered to be any open water below a latitude of 60 degrees south, the ocean forms an almost perfectly round boundary around Antarctica, encircling this impressive but barren landscape.
A concise history of the Southern Ocean
The Southern Ocean is the youngest of them all, believed to have formed 30 million years ago when the continents of South America and Antarctica drifted apart and opened up what is known as the Drake Passage. While 30 million years may seem a long time, knowing that the Atlantic Ocean was formed 180 million years ago puts things into perspective.
The fourth-largest ocean after the Pacific, Atlantic, and Indian Oceans, the Southern Ocean covers a minuscule 4 percent of the planet’s surface — about the size of the United States or China. The only smaller ocean, the Arctic Ocean, lies at the Antarctic’s antipode in the northern hemisphere. While small in geographic size, the Southern Ocean actually holds 150 times more water than all of the rivers in the world combined.
The extreme climate makes the Southern Ocean one of the coldest and most distinct places on earth. Water temperatures fluctuate between a chilly 50°F in the height of summer and a biting -85°F in the long winters.
Despite the inhospitable conditions, wildlife is abundant. Fur seals, blue whales, penguins, and squid all call the Antarctic, or Southern Ocean, with many of them surviving directly or indirectly on the phytoplankton that thrives off the icy shores.
Does the Southern Ocean actually exist?
The existence of the ocean itself has been contested by cartographers, oceanographers, and geographers for decades. Many argue that this region is merely a majestic confluence of the Indian, Pacific, and Atlantic Oceans, rather than an independent entity. When publishing maps, the National Geographic Society doesn’t classify the Antarctic Ocean as a separate body of water and refers to it as an extension of the world’s other oceans.
How deep is the Southern Ocean?
Despite not boasting the deepest point of all the earth’s oceans — an accolade that goes to the Mariana Trench, in the western Pacific — the Southern Ocean is not shallow. Most of the ocean has a depth ranging between 13,120 feet and 16,404 feet. The deepest point is the mysterious South Sandwich Trench, which plummets to 13,965 feet. Little is known about the trench, as exploration at these depths and temperatures is notoriously difficult.
The future of the Southern Ocean
The anthropization of the world's oceans due to climate change is a grave concern for both environmentalists and scientists. Antarctic species are dependent on the krill and algae that flourish under sea ice — the Adélie penguin is one beloved creature that has seen a notable decline in numbers in recent years. The gargantuan masses of ice that form in the Southern Ocean every year also play an integral role in regulating global temperatures, and should temperatures continue to rise, lack of ice formation and possible meltwater could have devastating effects.