If you had to draw the boundaries of the Earth's oceans on a map, would you be able to? The answer is no—because there is really only one "world ocean." Oceanographers have divided the world ocean into four principal areas, or basins: the Pacific, Atlantic, Indian, and Arctic Ocean basins. The Atlantic, Indian, and Pacific Ocean basins merge into icy waters around Antarctica. Some oceanographers define this as a fifth ocean, usually called the Antarctic or Southern Ocean basin.


This video focuses on the Pacific Ocean basin and is taken from the interactive online game, My Ocean. Test your ocean knowledge and learn about the different basins of the world ocean by playing here.

  • Covering one third of Earth's surface, the Pacific Ocean is the largest ocean in the world.
  • The North Pacific Subtropical Gyre is a slowly moving, clockwise spiral of currents that takes up about three times the area of the continental United States. It is the site of the Great Pacific Garbage Patch, a concentration of trash between California and Hawaii that covers an area roughly twice the size of Texas.
  • The Great Barrier Reef, the largest reef system in the world, is found in the Pacific Ocean. It is located off the northeastern coast of Australia and is made up of 2,900 individual reef ecosystems. The Great Barrier Reef is so large that it can be seen from space.
  • The Pacific Ocean is home to many hydrothermal vents. Hydrothermal vents are a type of deep-sea ecosystem that form around a fissure, or crack, in the Earth's surface between two tectonic plates. Large chimneys grow very quickly at these vents. The chimneys are created from dissolved metals that form into particles when the super-hot vent water meets the surrounding deep ocean water, which is very cold. One of the largest known chimneys was called "Godzilla." It reached the height of a 15-story building before it fell.
  • The deepest known point in the ocean, the Mariana Trench, is found in the Pacific Ocean. Nearly 11.3 kilometers (7 miles) deep, the Mariana Trench is deeper than Mount Everest is tall. This means that if Mount Everest sat at the bottom of the Mariana Trench, its peak would not break the surface of the water.

measure of how deep something is.

Mariana Trench

deepest place on Earth, located in the South Pacific Ocean at 11,000 meters (36,198 feet) at its deepest.


large body of salt water that covers most of the Earth.

Pacific Ocean

one of Earth's four oceans, bordered by North America, South America, Australia, Asia, and Antarctica.