Largest and Smallest Oceans

The Pacific Ocean (the North and South Pacific combined) is the largest ocean on the Earth, and at 155 000 000 square kilometres, covers about a third of the Earth's surfaces and has an area greater than all the land masses on the planet.

The smallest ocean is the Arctic Ocean, with an area of about 14 000 000 square kilometres.

The other oceans in order of size are: Atlantic Ocean (80 000 000 sq km), Indian Ocean (73 000 000 sq km, about a seventh of the Earth's surface), and Southern Ocean (20 300 000 sq km).

(The boundaries of oceans and seas change over time so the areas given here are approximate.)

Even More Fast Ocean Facts

Oceans and Seas

The five oceans are divided into more than 100 seas. Oceans are very deep and their floors can be mountainous, containing great ridges and trenches (see below). Ocean floors are composed of dense material created by movements in the tectonic plates.

Seas occur in shallower area surrounding continental land masses, where parts of the continents are underwater. Sea floors are softer and covered in mud, sand and other sedimentary material.

Larger seas, such as the Meditteranean, can include smaller seas, such as the Aegean Sea.

Mountains and Trenches

Massive trenches exist in the ocean. The deepest is the Mariana Trench in the Pacific, plunging more than 11 000m beneath the surface.

The tallest mountain on Earth also exists under the waves of the Pacific: Mauna Kea, which stands over 10 000m above the sea floor. The longest mountain range in the world is also underwater: the Mid-Atlantic Ridge stretches for 20 000km down the centre of the Atlantic Ocean.

Salty Seas

The dominant mineral in seawater is salt. Some of the salt originated in rocks, where it was dissolved by rain and river water, and carried out to sea. This process still continues. But sea salt also developed after sodium was released into the water from the ocean floor billions of years ago.

Salt levels in the ocean, on average, are about 3.5% but this varies with location, depending on factors such as air temperature and evaporation. You can taste the saltiness of the sea by dissolving a teaspoon of salt in a glass of water.

There are many other minerals in seawater, including other types of salt, and even precious metals such as gold and silver.

“Just as the wave cannot exist for itself, but is ever a part of the heaving surface of the ocean, so must I never live my life for itself, but always in the experience which is going on around me.” Albert Schweitzer

“I'm an ocean, because I'm really deep. If you search deep enough you can find rare exotic treasures.” Christina Aguilera

“Have you ever watched a crab on the shore crawling backward in search of the Atlantic Ocean, and missing? That's the way the mind of man operates.” Henry Louis Mencken

“I pray to be like the ocean, with soft currents, maybe waves at times. More and more, I want the consistency rather than the highs and the lows.” Drew Barrymore

“No nation ever had two better friends than we have. You know who they are? The Atlantic and Pacific oceans.” Will Rogers

“Man cannot discover new oceans unless he has the courage to lose sight of the shore.” Andre Gide

“The naturalists of yore esteemed the ocean to be a treasury of wonders, and sought therein for monstrosities and organisms contrary to the law of nature, such as they interpreted it.” Edward Forbes