Atlantic Ocean

The Atlantic is the second-largest ocean, about 106.5 million square kilometers (41.1 million square miles) of water separating the Americas from Europe and Africa. Long and relatively narrow, shaped like a stretched letter S, it formed as the supercontinent Pangaea tore apart and the New World drifted away from the Old. That same rifting continues today along its floor, making the Atlantic the most thoroughly explored and historically traveled of the oceans.

Down its center runs the Mid-Atlantic Ridge, the longest mountain range on Earth, a submarine seam where new ocean crust is born and the seafloor slowly spreads. It surfaces in places as volcanic islands such as Iceland and the Azores. The ocean reaches its greatest depth, about 8,376 meters (27,480 feet), in the Puerto Rico Trench. Its powerful Gulf Stream carries warm tropical water northeast, moderating the climate of western Europe far beyond what its latitude would suggest.

For five centuries the Atlantic has been the world's busiest corridor of exchange — of explorers and migrants, goods and ideas, and the forced passage of enslaved people. Its circulation is a key engine of global climate, and scientists watch closely for signs that warming and freshwater melt could weaken the currents that keep the North Atlantic mild.

• Africa
  The world's second-largest continent and humanity's birthplace borders
• Europe
  A small, intricate continent of outsized influence borders
• North America
  The third-largest continent, from the Arctic to the tropics borders
• South America
  A continent of the Andes, the Amazon, and dazzling extremes borders
• Arctic Ocean
  The smallest and shallowest ocean, capped by sea ice connected ocean
• Pacific Ocean
  Earth's largest and deepest ocean connected ocean
• Southern Ocean
  The youngest-named ocean, encircling Antarctica merges with