Ocean? What Is an

An ocean is a huge saltwater body surrounding the continent that covers twothirds or 71 percent of the Earth’s surface. It is home to vast aquatic animal species and organisms, as well as coral reefs.

Earth’s smallest ocean is the Arctic Ocean and the deepest is the Pacific Ocean. Various water movements distinguish the Antarctic (or Southern) Ocean from the Atlantic, Pacific, and Indian Oceans.

The temperatures of the oceans are different in the various parts of the world. For example, icebergs are formed by very cold waters near the poles, while waters around the equator are relatively warm.

There are various hypotheses for the origins of water on Earth. One widely held view is that the atmosphere and the oceans accumulated gradually over millennia with the “degassing” of the interior of the Earth: Water vapour escaping from the molten rocks of the early Earth condensed into rain and filled the basins that are our oceans. Another theory suggests that the oceans could not form out of the protoplanetary disk because it was much too hot for water to condense. Instead, water was delivered to Earth by impacts from icy planetesimals originating at a distance from the Sun where ice could form.