Earth's Many Oceans
More than two-thirds of the Earth is covered by water mostly from four oceans. They vary in size but one thing they they have in common is salt.
Why are the oceans salty?
The answer: It builds from the streams that flow into them. The streams deposit the salt it gathers from its rocks and soil. When the ocean water evaporates, the salt doesn't and gets left behind, making the remaining water salty.
The four oceans from largest to smallest are: The Pacific. It takes up 47 percent of the Earth's water area. It's home to the largest number of coral reefs, including the 1,429-mile-long Great Barrier Reef.
Covering 25 percent water area is the Atlantic Ocean. Its deepest point is the Puerto Rico Trench that is over 28,200 feet deep.
The Indian Ocean is one of the world's largest breeding grounds for humpback whales.
And, last but not least, the smallest ocean – the Arctic - covers 4 percent of the Earth's water area. Remarkably, its ocean floor contains 12 volcanoes.
Content provided by Oakland University.
