The Online Library of Knowledge


What's it like under the ocean?

The Pacific Ocean as seen from spaceThe Pacific Ocean as seen from spaceMore than two-thirds of the Earth’s surface is covered by the waters of the oceans. About 97% of the Earth’s water is found in the oceans. There are five oceans. In order of size, they are: the Pacific, Atlantic, Indian, Arctic and Southern. We often use the word "sea" to mean ocean, although seas are really smaller parts of the ocean partly enclosed by land—for example the Mediterranean Sea or North Sea.

Ocean currents

A map of ocean currentsA map of ocean currentsAn aerial view of ocean currentsAn aerial view of ocean currentsThe ocean waters move around the globe in huge swirling currents. Surface currents are driven by the winds. They flow in roughly circular patterns: clockwise in the northern hemisphere and anticlockwise in the southern hemisphere. Some currents are warm while others are cold. They have a major effect on the climates of lands bordering the ocean. This is because the winds above the ocean are warmed (or cooled) by the waters below.

Ocean floor

The Mid-Oceanic Ridge snakes across the ocean floor for a distance of 65,000 kilometres (40,000 miles). It is the world's longest mountain range.

© 2020 Q-files Ltd. All rights reserved. Switch to Mobile