The Earth's five oceans are: the Pacific, the Atlantic, the Indian, the Southern and the Arctic. Whereas the Pacific Ocean is the largest, spanning 60,060,700 square miles, the Arctic is the smallest, extending only 5,427,000 square miles.
The five oceans take up 71 percent of the Earth's surface. Until the year 2000, only four oceans were recognized. During the spring of that year, the International Hydrographic Organization included the Southern Ocean.
The Pacific Ocean is surrounded by volcanoes known collectively as the Ring of Fire. These areas are responsible for frequent volcanic eruptions and earthquakes. This region is home to 75 percent of the world's active volcanoes, and 90 percent of its earthquakes.
Oceans separate the continents. The Pacific separates Asia and Oceania from the Americas. The Atlantic separates the Americas from Eurasia and Africa. The Indian separates Africa from Australia. Antarctica is surrounded by the Southern. The Arctic, which is sometimes considered part of the Atlantic, touches the Arctic, North America and Eurasia.
Many organisms make the world's oceans their home, including fish, jellyfish, whales and dolphins, octopus, squid, lobsters, clams, shrimp and marine worms. In addition to the animals that spend all their time in water, there are several, such as sea turtles, penguins and pelicans, that make use of the adjacent land.