An ocean is a continuous body of salt water that is contained in an enormous basin on Earth’s surface. The major oceans and their marginal seas cover nearly 71 percent of Earth’s surface, with an average depth of 3,688 metres (12,100 feet).

ocean

Table of Contents

References & Edit History Quick Facts & Related Topics

Images, Videos & Interactives

Boundaries of the world's oceans and seas

For Students

ocean summary

ocean

Q: What are the five oceans of Earth?

The five major oceans are the Pacific , Atlantic , Indian , Arctic , and Southern oceans.

Q: Which is the largest ocean on the Earth?

The Pacific is the largest ocean in both surface area and volume. The Atlantic is the next largest, and the Arctic is the smallest.

Q: How much of the water found on Earth exists in the oceans?

By volume, 97.957 percent of the water on Earth exists as oceanic water and associated sea ice. Earth is unique in the solar system because its mean temperature allows water to exist on Earth in all three phases—solid, liquid, and gaseous—with the liquid phase predominating.

Q: Should bottled water be banned to lower plastic pollution in the ocean?

Whether bottled water should be banned lower plastic pollution in the ocean is hotly debated. Some say banning bottled water would reduce waste and protect the environment while saving money. Others say banning bottled water removes a healthy choice and leads to increased consumption of unhealthy sugary drinks. For more on the bottled water ban debate, visit ProCon.org .

Earth feature

Also known as: world ocean

Written by Alyn C. Duxbury, Claudia CenedeseSee All

Fact-checked by The Editors of Encyclopaedia Britannica

Article History

Earth's oceans

See all media

Category: Geography & Travel

Key People:: Jacques Cousteau; Charles William Peach; Sir C. Wyville Thomson; Addison Emery Verrill

Related Topics:: iceberg; ocean current; ocean basin; sea ice; oceanic crust

See all related content →

What is an ocean?

What are the five oceans of Earth?

Which is the largest ocean on the Earth?

How much of the water found on Earth exists in the oceans?

Should bottled water be banned to lower plastic pollution in the ocean?

ocean, continuous body of salt water that is contained in enormous basins on Earth’s surface. When viewed from space, the predominance of Earth’s oceans is readily apparent. The oceans and their marginal seas cover nearly 71 percent of Earth’s surface, with an average depth of 3,688 metres (12,100 feet). The exposed land occupies the remaining 29 percent of the planetary surface and has a mean elevation of about 840 metres (approximately 2,755 feet). Actually, all the elevated land could be hidden under the oceans and Earth reduced to a smooth sphere that would be completely covered by a continuous layer ...(100 of 2198 words)

Access the full article

Help support true facts by becoming a member.