Oceans play an integral role in many of the Earth's systems. The ocean supports the life of nearly half of all species on Earth, providing 20 percent of the animal protein and five percent of the total protein in the human diet.
Though there generally are considered to be four different oceans, there are no physical divisions separating them, thus the water flowing through them is the same. The five major oceans on Earth are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean, and the Southern Ocean.
The Pacific Ocean, the Earth's largest ocean, flows to the west of the Americas and along the eastern edge of Asia. The Pacific Ocean is sometimes divided into the North Pacific and the South Pacific. The Atlantic Ocean is between the Americas and Europe and Africa, and like the Pacific, the Atlantic is also sometimes divided into the North and South Atlantic.
The Indian Ocean is situated below the Indian subcontinent, to the east of Africa and the west of Australia and the islands like Malaysia and Indonesia. The Arctic Ocean is around the north pole, and is the shallowest ocean of all - sometimes considered a sea rather than an ocean. The Arctic is encompassed primarily by North America and Russia, and its waters are partially covered by ice year-round. The International Hydrographic Organization designated the waters surrounding Antarctica to be the Southern Ocean in the year 2000, extending to the latitude of 60 degrees.
The oceans of Earth serve many functions, playing an integral role in the Earth's weather and temperature. Oceans moderate the Earth's temperature by absorbing incoming solar radiation. The continuously moving ocean currents distribute the heat energy around the globe, heating the land and air during winter cooling it during summer.
|Ocean||Area||Average Depth||Deepest Point|
|Pacific||64,186,000 square miles||15,315 feet||Mariana Trench (36,200 feet below sea level)|
|Atlantic||33,420,000 square miles||12,881 feet||Puerto Rico Trench (28,231 feet below sea level)|
|Indian||28,350,000 square miles||13,002 feet||Java Trench (25,344 feet below sea level)|
|Southern||7,848,300 square miles||13,100-16,400 feet||South Sandwich Trench (23,736 feet below sea level)|
|Arctic||5,106,000 square miles||3,953 feet||Eurasia Basin (17,881 feet below sea level)|
- The Pacific Ocean is the largest of the four main oceans
- The Atlantic Ocean is the busiest ocean. Many ships cross the Atlantic, carrying cargo between the Americas, Africa, and Europe
- The Arctic Ocean is the smallest and coldest ocean
- The average temperature of all oceans is about 39 degrees F (3.8 degrees C)
- Oceans are always moving
- Tides change twice a day all over the world, as the oceans rise and fall along the shoreline. Scientists think this is caused by the pull of the sun and moon on our Earth, and the Earth's rotation.
- Coral reefs are vast, rocky areas located in shallow, tropical waters. Coral reefs are like the tropical rain forest of the ocean in that the greatest variety of plant and animal life in the ocean live there. Coral reefs are formed from the bodies of small sea creatures called polyps
- The world's oceans contain nearly 20 million tons of gold
|Top ten longest rivers|
|Nile (Africa)||6,693 km|
|Amazon (South America)|| 6,436 km|
| Mississippi-Missouri (North America)||6,238 km|
|Yenisey-Angara (Asia) ||5,981 km|
|Ob-Irtysh (Asia)||5,569 km|
|Yangtze (Asia)||5,525 km|
|Yellow (Asia) ||4,671 km|
|Amur (Asia) ||4,352 km|
|Lena (Asia)||4,345 km|
|Congo (Africa)||4,344 km|
Top ten largest natural lakes (by surface area)
|Caspian Sea (Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan)||372,960 sq km|
|Lake Superior (Canada, United States)||82,414 sq km|
|Lake Victoria (Kenya, Tanzania, Uganda)||69,490 sq km|
|Lake Huron (Canada, United States)||59,596 sq km|
|Lake Michigan (United States)||57,441 sq km|
|Lake Tanganyika (Burundi, Democratic Republic of the Congo, Tanzania, Zambia)||32,890 sq km|
|Great Bear Lake (Canada) ||31,800 sq km|
|Lake Baikal (Russia)||31,494 sq km|
|Lake Nyasa (Malawi, Mozambique, Tanzania)||30,044 sq km|
|Great Slave Lake (Canada) ||28,400 sq km|
|Rank||Name||Drainage area (1000 km2)|
|4||La Plata||3 100|
|17||St. Lawrence*||1 030|
:This table ranks the world's largest rivers by length in kilometers.
|5||La Plata||4 700|
|6||Hwang Ho||4 670|
|16||St. Lawrence*||3 060|
This table ranks the world's largest rivers by average annual total discharge in kilometers cubed per year.
Based on average annual total discharge
|Rank||Name||Average annual total discharge (km3/year)|
Adapted from World Water Resources and Their Uses, Joint SHI/UNESCO Product, prepared by Prof. Igor A. Shiklomanov, 1999.
Last Updated on: May 12, 2017