What Is an Ocean?
An ocean is a large and continuously flowing body of salty water covering most of the earth’s surface. There are five major oceans—the Pacific, Atlantic, Indian, Southern and Arctic—which cover approximately 97% of the world’s surface. All oceans are interconnected via currents and tides. They form a single global system, which makes up 70% of the total volume of the world’s water.
The largest ocean is the Pacific Ocean, which covers about 30% of the globe. Its size is equivalent to half of the entire freshwater supply on Earth. The second largest ocean is the Atlantic Ocean, which accounts for about 20% of the world’s water volume.
How Many Oceans Exist?
The five oceans are located in three separate regions of the world. All of them are salty because they’re filled with ocean water. There’s no freshwater in the oceans, just saltwater. But how many oceans do there actually need to be? Let’s find out.
In terms of volume, the largest ocean is the Pacific Ocean. It covers an area about 3.8 times larger than the United States. This is followed by the Atlantic Ocean, covering 2.7 times larger landmass than the US. Then there’s the Indian Ocean, covering twice as much landmass as the US. And finally, the third largest body of water is the smallest one: the Arctic Ocean.
But wait, you might say. Doesn’t the Antarctic count too? Yes, the South Pole is part of the continent of Antarctica, but the term “ocean” doesn’t refer to the entire globe. So technically, there are four oceans.
Why Do We Call Them Oceans?
When humans first began exploring the world, they noticed that the sea was divided into two distinct parts. One was fresh, while the other was salty. These waters were so different from each other that it seemed like they belonged to two completely different worlds.
So people started calling these bodies of water “oceans.” In fact, this word comes from Greek mythology. According to legend, when Zeus created the universe, he threw his thunderbolts at the Titans, who lived underwater. As punishment, the Titans were condemned to live under the waves. Hence, the name “Oceanus,” meaning “underworld.”
How Big Is Each Ocean?
The biggest ocean in the world is the Pacific Ocean, followed by the Atlantic Ocean. These two oceans cover about three quarters of Earth’s surface area, making up 70 percent of our planet’s total body of water. Next up is the Indian Ocean, covering over 10 million square miles. The third largest ocean is the Arctic Ocean, which covers around 7.5 million square miles. Finally, the fifth largest ocean is the Southern Ocean, which covers roughly 5.6 million square miles.
Top 10 Largest Oceans and Seas in the World
1. The Pacific Ocean | 168,723,000 square kilometers
The Pacific Ocean covers about 20 million square miles (53 million square kilometers), making it the largest body of saltwater in the world. It is bounded by Asia to the east and North America to the north and south, and includes many islands scattered across the globe.
The Pacific Ocean is separated into five basins: the Arctic Basin, the Central American Basin, the Eastern Pacific Basin, the Western Pacific Basin, and the Southwestern Indian Basin.
The Pacific Ocean contains some of the most biologically rich waters on Earth, including coral reefs, kelp forests, and underwater mountains called seamounts. Some of the best diving spots are found along the coasts of Mexico, Japan, Australia, New Zealand, and California.
In addition to being the world’s largest ocean, the Pacific also holds the record for having the deepest trench on Earth. Located in the Mariana Trench, the bottom of the trench reaches a staggering 10,911 meters (36,037 ft). This makes the Pacific Ocean the second-deepest body of water behind the Atlantic Ocean.
2. The Atlantic Ocean | 85,133,000 square kilometers
The Atlantic Ocean is the second largest ocean in the world, behind the Pacific Ocean. The Atlantic Ocean covers approximately 20% of the Earth’s surface. It is separated from the North Sea by Denmark, Norway, Iceland, Scotland, Ireland, England, Wales, France, Spain, Portugal, Morocco, Algeria, Tunisia, Libya, Egypt, Sudan, Kenya, Tanzania, Mozambique, Malawi, Zambia, Zimbabwe, Botswana, Namibia, South Africa, Angola, Ghana, Senegal, Mauritania, Mali, Guinea, Liberia, Ivory Coast, Burkina Faso, Benin, Niger, Nigeria, Togo, Chad, Cameroon, Central African Republic, Congo, Equatorial Guinea, Gabon, Sao Tome & Principe, Sierra Leone, Ethiopia, Somalia, Djibouti, Eritrea, Saudi Arabia, Yemen, Oman, United Arab Emirates, Bahrain, Qatar, Kuwait, Iraq, Iran, Afghanistan, Pakistan, Turkmenistan, Uzbekistan, Tajikistan, Mongolia, China, Korea, Japan, Taiwan, Thailand, Indonesia, Malaysia, Brunei Darussalam, Australia, New Zealand, Chile, Peru, Colombia, Ecuador, Venezuela, Guyana, Suriname, French Guiana, Paraguay, Uruguay, Antarctica, Brazil, Argentina, Chile, Easter Island, Greenland, Mexico, Cuba, Jamaica, Puerto Rico, Dominican Republic, Panama, Trinidad & Tobago, Honduras, Guatemala, El Salvador, Nicaragua, Costa Rica, Belize, Saint Lucia, Barbados, Saint Vincent & Grenadines, Antigua & Barbuda, Bahamas, Bermuda, Turks & Caicos Islands, United States Virgin Islands, Saint Kitts & Nevis, Anguilla, Montserrat, British Virgin Islands, Cayman Islands, Aruba, Curacao, Martinique, Guadeloupe, Dominica, Haiti, Saint Pierre & Miquelon, Saint Maarten, Saint Martin, Saint Barthélemy, Saint Helena, Ascension Island, Tristan da Cunha, Falkland Islands, Macquarie Island, Kerguelen Islands, Réunion, Cocos (Keeling) Islands, Heard Island & McDonald Islands, Diego Garcia, Chagos Archipelago, Maldives, Seychelles, Sri Lanka, Madagascar, Mayotte, Mauritius, Rodrigues, Reunion, Bali, Lombok, Timor Leste, Western Sahara, Cambodia, Laos, Vietnam, Myanmar, Yunnan Province, Guangxi Zhuang Autonomous Region, Guangdong Province, Hainan Province, Chongqing Municipality, Sichuan Province, Tibet Autonomous Region, Qinghai Province, Gansu Province, Ningxia Hui Autonomous Region, Xinjiang Uygur Autonomous Region, Inner Mongolia, Heilongjiang Province, Jilin Province, Liaoning Province, Neimenggu Province, Shanghai Municipality, Zhejiang Province, Anhui Province, Jiangsu Province, Henan Province, Hubei Province, Hunan Province, Fujian Province, Shandong Province, Shaanxi Province, Shanxi Province, Beijing Municipality, Tianjin Municipality, Hebei Province, Tianjin Municipality.
3. The Indian Ocean | 70,560,000 square kilometers
The Indian Ocean is the largest body of water located entirely within one continent. At 3.8 million square miles (9.7 million square kilometers), it is the third-largest global ocean, covering approximately 1/5th of Earth’s total land area. It lies east of Asia and west of Africa, stretching from the southern tip of Africa to Indonesia and beyond.
The Indian Ocean is bounded by the African coastline to the northwest, the Antarctic coast to the south, the Malay Peninsula to the northeast, and the Australian mainland to the southeast. The Arabian Sea separates the Indian Ocean from the Gulf of Oman; the latter connects the Indian Ocean to the Persian Gulf via the Strait of Hormuz. To the north are the Red Sea and the Gulf of Aden.
The Indian Ocean contains many large island groups, including Madagascar, Mauritius, Seychelles, Sri Lanka, Maldives, Comoros, Kenya, Tanzania, Zanzibar, Mauritius, Réunion Island, Mayotte, La Reunion, Somalia, Djibouti, Yemen, Socotra, Andaman Islands, Maldives, Chagos Archipelago, Borneo, Sumatra, Java, Sulawesi, New Guinea, Timor, Flores, Vanuatu, Fiji, Tonga, Samoa, American Samoa, Wallis and Futuna, French Polynesia, Tuvalu, Kiribati, Cook Islands, Niue, Easter Island, Pitcairn Islands, Marshall Islands, Micronesia, Palau, Cocos Keeling Islands, Christmas Island, and
4. The Southern Ocean | 21,960,000 square kilometers
The Southern Ocean, also known simply as Antarctica, is the world’s third-largest ocean, covering about 20% of Earth’s total surface area. It lies south of both the Pacific and Indian oceans, north of Australia and New Zealand, and west of South America. Its name derives from the fact it is surrounded by land—the continent of Antarctica, the Southern Cross constellation, and the Antarctic Plateau.
Some scientists do not recognize the ocean at all, because there are no physical features that define the edge of the sea. Others argue over whether some parts of the ocean should be included in the definition. For example, the International Hydrographic Organization defines the boundary of the Southern Ocean as extending southward from 60 degrees south latitude, while others include the entire region bounded by the Antarctic Convergence, the Polar Front, and the 50th parallel south.
Famously, explorer Captain James Cook circumnavigated the globe in the late 18th century, sailing along the coast of the Southern Ocean. He named the coastline he discovered “New Land”, later renamed “Australia”. In the mid 19th century, many explorers sailed into the Southern Ocean looking for a passage to India. They found none, but did find the Antarctic ice shelf, which had been observed since ancient times.
5. The Arctic Ocean | 15,558,000 square kilometers (smallest ocean)
The Arctic Ocean is the world’s smallest and shallowest ocean, covering about 14 million square miles (37 million square kilometers). Its size makes up less than one percent of Earth’s total surface area. It includes the North Pole, which is recognized as the coldest of all the oceans with low salinity.
Researchers have had difficulty studying the Arctic Ocean because of the extreme conditions. Sea ice covers the water most of the year. During the winter months, the ocean is often completely frozen over. This makes diving into the ocean difficult. Scientists must dive through the ice into dark waters. They use special equipment to study how the ocean works and what lives there.
6. Coral Sea
The Coral Sea is a body water rich in biodiversity. It is located in the Pacific Ocean, north of Australia. It is bounded by Queensland, Vanuatuan, and New Caledonian territories.
The sea is a popular tourist attraction because it offers diving sites, coral reefs, and islands. It is also known for being very calm, making it a good place to study ocean currents.
7. Arabian Sea
The Arabian Sea covers an area of 3,862,000 sq mi (9,859,000 km²), making it one of the world’s largest bodies of water. It is bounded by India to the north, Pakistan to the northeast, Afghanistan to the east, Sri Lanka to the southeast, Bangladesh to the south, Myanmar to the southwest, and Oman, Saudi Arabia, Qatar, United Arab Emirates, Kuwait, Bahrain, Iraq, Iran, Israel, Jordan, Egypt, Sudan, Eritrea, Ethiopia, Djibouti, Somalia, Kenya, Tanzania, Uganda, Malawi, Zambia, Zimbabwe, Botswana, Namibia, South Africa, Swaziland, Mozambique, Lesotho, Madagascar, Mauritius, Réunion Island, Seychelles, Comoros, Mayotte, Madagascar, Reunion, Mauritius, Rodrigues, Saint Helena, Ascension Island, Tristan da Cunha, Gough Island, Prince Edward Islands, Prince Christian Island, Marion Island, Crozet Islands, Kerguelen Islands, Heard Island, McDonald Islands, Desolation Island, Peter I Island, Queen Maud Land, Princess Astrid Coast, Princess Elizabeth Coast, Princess Alice Coast, Princess Margret Coast, Princess Ragnhild Coast, Princess Victoria Coast, Princess Alexandra Coast, Princess Grace Coast, Princess Alice Coast and Princess Beatrice Coast.
8. South China Sea
The South China Sea is one of the most contentious areas in the world today. Its name is derived from the fact that it lies south of China. In reality, however, the term refers to several bodies of water including the Paracel Islands, Spratly Islands, Scarborough Shoal, Bajo de Masinloc, Subi Reef, and others. These islands and reefs stretch over 1,400,000 sq km, about 3,500,000 sq km, making it larger than India.
China claims sovereignty over almost all of the South China Sea, while Brunei, Malaysia, Vietnam, the Philippines, Taiwan and Indonesia also lay claim to parts of it. The United States does not recognize Chinese sovereignty over any of the land features in the sea, and considers freedom of navigation there to be vital to US security interests.
9. Caribbean Sea
The Caribbean Sea is located around North America to the west and south. To the northeast lies the Gulf of Mexico. To the northwest lie Bermuda and Puerto Rico. To the southeast are Cuba, Hispaniola, the Dominican Republic, Haiti, Jamaica, and Saint Lucia. To the southwest are the Windward Passage and the Leeward Passage.
To the north is the Atlantic Ocean, and to the south is the Pacific Ocean. The Caribbean Sea is bordered on the west by Mexico and Central America.
The Caribbean Sea covers an area of about 2,754,000 square kilometers (1,063,000 sq mi). Its average depth is 3,500 meters (11,480 ft), making it the second largest body of water entirely within North America.
The Caribbean is sometimes referred to as the “Caribbean Sea”, even though technically there are no seas inside the region, just oceans.
10. Mediterranean Sea
The Mediterranean Sea is one of Earth’s largest bodies of water covering an area of about 2,500,000 square kilometers (1 million square miles). This makes it the fifth largest body of water behind the Arctic Ocean, Pacific Ocean, Indian Ocean and Atlantic Ocean. It is bounded by three continents – Europe, Asia and Africa – and is separated from the Atlantic Ocean by the narrow Iberian Peninsula.
What are the three largest oceans? “The Pacific Ocean, the Atlantic Ocean, and the Indian Ocean.”
– These are the three largest oceans in terms of surface area.
– There are many smaller bodies of water within each ocean, including the Mediterranean Sea, the Arctic Ocean, and the Baltic Sea.
How do you measure the size of an ocean?
You can use a ruler or a tape measure, but the most accurate way to determine how big an ocean is is to use a globe. You can find one online or buy one at a store like Target or Walmart. Place the globe over the body of water you want to measure and look for the label “Earth”. If it says “Earth”, then you know that the ocean is about 10,000 miles long.
What are some famous places located near the ocean?
Many people think of Hawaii or Florida when thinking about beaches near the ocean. But there are actually lots of different places that have beautiful beaches nearby. Here are just a few:
Which is larger, an ocean or sea?
The world’s oceans cover 71 percent of Earth’s surface. But what do you think is bigger: an ocean or a sea? If you guessed an ocean, you’re wrong. A sea covers about 70 percent of Earth’ s surface. This includes the Arctic Sea, Baltic Sea, Black Sea, Bering Strait, Caribbean Sea, Coral Sea, Gulf of Mexico, Indian Ocean, Mediterranean Sea, North Atlantic Ocean, Pacific Ocean, Red Sea, South China Sea, Tasman Sea, White Sea, Yellow Sea and others.
So how did we come up with this number? We used data from NASA’s World Topography Map Project, which measures the elevation of the earth’s surface. Using this data, we calculated the area of each body of water. Then we compared it to the total area covered by oceans.
What is the largest ocean in the world?
The largest ocean in the world—the Pacific Ocean—is 63,800,000 sq mi (165,250,00 km2), according to the World Ocean Database, a project of the University of California San Diego’s Scripps Institution of Oceanography. This is roughly one quarter larger than the Atlantic Ocean, making it the third largest body of water in the world.
The Pacific Ocean covers about 30% of Earth’s total surface area. Its volume is approximately equal to the combined areas of Australia, Canada, China, France, Germany, India, Japan, Mexico, New Zealand, Norway, South America, Spain, Sweden, Switzerland, the United Kingdom, and the United States.
What is the smallest ocean in the world?
The Arctic Ocean is the fifth largest body of water in the world. It covers about 14 million square miles (36.1 million square kilometers), making it slightly smaller than the Atlantic Ocean.
The Arctic Ocean is located north of North America and south of Siberia. Its name derives from the fact that it shares borders with both the Northern Hemisphere and Southern Hemisphere. It is bordered by Canada, Greenland, Norway, Russia, Sweden, Finland, Iceland, and the United States.
Parts of the Pacific Ocean
The Pacific Ocean is one of Earth’s largest bodies of water. Its surface covers about 20% of the planet’s total landmass, making it the world’s fourth-largest body of water behind the Atlantic, Indian, and Arctic oceans. It stretches from the Southern Hemisphere across the equator, covering an expanse of around 24 million square kilometers.
The Pacific Ocean is bounded on the west by North America and Asia, and on the east by Australia, New Zealand, Japan, South Korea, China, Taiwan, and the Philippines. The International Hydrographic Organization defines the limits of the Pacific Ocean as follows: “From the Antarctic Pole of Inaccessibility to longitude 160° East, thence along the parallel of latitude 60° N., to the Eastern limit of the Sea of Okhotsk; thence southward along the meridian of 135° E. to Cape Horn.” The Pacific Ocean contains many islands, including Hawaii, Guam, Samoa, Fiji, Tonga, Vanuatu, Kiribati, Tuvalu, Tokelau, Nauru, Palau, Papua New Guinea, Solomon Islands, Marshall Islands, Northern Mariana Islands, Federated States of Micronesia, Republic of Palau, Cook Islands, Easter Island, Pitcairn Islands, French Polynesia, Wallis and Futuna Islands, Niue, American Samoa, Midway Atoll, Johnston Atoll, Kingman Reef, Wake Island, Jarvis Island, Howland Island, Baker Island, Jarvis Island, Navassa Island, San Nicolas Island, Escudo de Veraguas, Chagos Archipelago, Cocos Islands, Christmas Island, Heard Island and McDonald Islands, Laysan Island, Lisianski Island, Phoenix Islands, Wake Island, Midway Atoll and Line Islands.
Which Ocean is the Deepest?
The Pacific Ocean is the largest ocean on Earth, covering an incredible 7.7 million square kilometers. It is also the deepest, with a maximum depth of about 6.8 miles. This vast body of water covers most of the planet’s landmass, including Australia, New Zealand, Japan, China, India, Indonesia, Papua New Guinea, Mexico, Canada, the United States and even Antarctica.
Surprisingly, a host of marine life thrives in the depths of the Pacific. Jellyfish, crabs, shrimp, lobsters, sea cucumbers, octopuses, squid, fish, sharks, rays, turtles, birds, whales and dolphins call the Pacific home.
In fact, the Pacific holds some of the deepest points in the entire world. There are three areas in particular where the Pacific ocean drops off into deeper waters: the Mariana Trench, the Tonga Trench and the Peru Trench. All three areas are located west of Hawaii and south of Guam and are among the deepest places in the world. They range from 6.5 to 6.8 miles deep.
The Mariana Trench is the deepest part of the Pacific, stretching nearly halfway around the globe. It is located east of the Marianas Islands and north of the equator. Its distance from the nearest continent, Asia, varies depending on how you measure it. Some say it extends 3,500 miles; others claim 4,200 miles. Either way, the Mariana Trench is one of the deepest spots in the world.
Next up is the Tonga Trench, which stretches across the middle of the Pacific Ocean. It lies roughly between Fiji and Samoa. Like the Mariana Trench and the Peru trench, the Tonga Trough is also considered to be a mid-oceanic trench. However, the Tonga Tract is much shallower than both the Mariana Trench or the Peru Trench, measuring only 2,900 feet deep.
Finally, there is the Peru Trench, located near the coast of Peru. It ranges from 8,100 feet deep to 9,300 feet deep. While it isn’t quite as deep as either the Mariana Trench nor the Tonga Trench is, the Peru Trench still ranks third in overall depth behind the Mariana Trench.
What Makes an Ocean an Ocean?
The word ocean comes from the Greek word meaning “sea,” so you might think that there is no real definition of what constitutes an ocean. But there is actually quite a lot of consensus among geographers about what defines an ocean.
All the oceans in the world cover about 71% of the Earth’s surface and contain approximately 97% of all of the world’s water. There are seven major oceans: Atlantic, Indian, Arctic, Southern, North Sea, South China Sea, and Antarctic Oceans. They are separated by landmasses and defined by physical characteristics like depth, temperature, salinity, and current flow.
Oceanography is a branch of science concerned with studying the properties of the oceans, including the structure and circulation of the oceans, and the role of the oceans within climate change.
Why Do We Call Them Differently?
When you look up the term ocean in a dictionary, you’ll find many definitions. Some say that an ocean is a large body of saltwater. Others define an ocean as a large sea. Still others say that an ocean is simply a body of salty water. And some dictionaries even include a definition saying that an ocean is a place where fish live.
But all those definitions don’t really help us figure out exactly what an ocean is. If you ask someone what an ocean is, most people probably won’t know. The best way to answer this question is to start with the basics. An ocean is a body of water surrounded by land. So, the first thing to determine is whether the water surrounding our planet is considered part of an ocean.
If the water surrounding our planet isn’t considered part of an ocean, then we’re left with three options: A large sea, a large body of salt water, or a place where fish live (which is not technically correct).