How many oceans are there in the world

GeoGarage blog

Daily press & media panorama with maritime thematic

Sunday, November 1, 2020

How many oceans are there in the world?

From World Atlas by Antonia Cirjak

Earth can have anywhere from 1 to 7 oceans, depending on how you look at it.

There is one global ocean called the World Ocean, because the entire body of water on our planet is connected.
Nowadays, it is widely accepted that the Earth has five oceans: the Arctic, Atlantic, Indian, Pacific, and the Southern Ocean.
The largest and the deepest ocean on our planet is the Pacific Ocean.
This ocean extends all the way from the Arctic to the Southern Ocean from north to south and is bound by the Americas in the east and Asia and Australia in the west.

Earth can have anywhere from 1 to 7 oceans, depending on how you look at it.
Yes, there is one global ocean called the World Ocean, because the entire body of water on our planet is connected.
It covers 71 percent of the surface of our planet, but we usually divide it into distinct regions, all named accordingly.
The Earth has five oceans: the Arctic, Atlantic, Indian, Pacific, and the Southern Ocean.

Over time, the boundaries we use to determine these regions have evolved due to various geographical, cultural, and historical reasons.
Nowadays, it is widely accepted that the Earth has five oceans: the Arctic, Atlantic, Indian, Pacific, and the Southern Ocean.

1. Arctic Ocean
Out of the five major oceans on our planet, the Arctic Ocean is the smallest and the shallowest one.

It is also the coldest one, which makes sense considering its geographical position.
Some oceanographers consider it a sea, but it is recognized as an ocean by the International Hydrographic Organization.

It is the northernmost part of the World Ocean, found in the Arctic north polar region.
It is surrounded by the continents of Eurasia and North America and is covered in sea ice in some parts.
The ice melts during specific times of the year, which can influence the temperature and salinity of the ocean.
On average, the Arctic Ocean has the lowest salinity out of all the five oceans.

2. Atlantic Ocean
The Atlantic Ocean is the second-largest ocean, and its area is determined to be 106,460,000 square kilometers.

This ocean covers about 20 percent of the surface of our planet.
The Atlantic Ocean is often looked at as the boundary between the “Old World” and the “New World.” It is shaped in the form of the letter “S,” and it occupies the space between North and South America to the west and Europe and Africa to the east.

It is also connected to all other oceans directly, so it can be considered the middle component of the World Ocean.
There were many famous explorations of this ocean throughout human history, such as the Challenger expedition and the German Meteor expedition, among others.

3. Indian Ocean
As the third-largest part of the World Ocean, covering 70,560,000 square kilometers, the Indian Ocean makes up for almost 20 percent of the water on the surface of our planet.

Asia surrounds this ocean on its north side, Africa, on the west, and Australia to the east.
On its south side, it is connected and wounded by the Southern Ocean.

Many regional seas can be found along with the core of the Indian Ocean, such as the Somali Sea, the Bay of Bengal, the Arabian Sea and the Laccadive Sea.
Monsoons and cyclones mostly dictate the climate in this ocean.
The Indian Ocean is the warmest out of all the five oceans on our planet, and it is known as a fruitful fishing ground.

4. Pacific Ocean
The largest and the deepest ocean on our planet is the Pacific Ocean.

This ocean extends all the way from the Arctic to the Southern Ocean from north to south and is bound by the Americas in the east and Asia and Australia in the west.
The size of this ocean is 165,250,000 square kilometers, which makes it the largest part of the World Ocean.
The Pacific Ocean covers 32% of the surface area of our planet, which means that it is larger than all of the land area on Earth when combined.

This ocean is usually divided into two subdivisions by the equator.
These are the Northern and the Southern Pacific Oceans.
On average, the depth in the Pacific Ocean is 13,000 feet.
It also features the deepest point in the world, the Challenger Deep that can be found in the Mariana Trench, and that reaches the depth of 35,853 feet.
Not only that, but the ocean also features the second and the third deepest points on our planet, the Horizon Deep (35,509 feet) and the Sirena Deep, respectively.

5. Southern Ocean
The Southern Ocean is often called the Antarctic or the Austral Ocean, and it is found in the southernmost part of the World Ocean.

This ocean encircles the continent of Antarctica, and it is the second smallest of the five oceans.
The Southern Ocean is known as being the zone where the colder waters from the Antarctic that are flowing northwards mix with the warm waters from subantarctic regions.
Throughout history, many have debated whether the Southern Ocean should be considered an ocean at all.

Many believed that it does not exist and considered it just to be various parts of other oceans.
However, in time researchers managed to discover how important Southern Circulation is and since this body of water-limited that circulation, they called it the Southern Ocean, thereby confirming that it does exist after all.

How Many Oceans Are There In The World?

The ocean is a massive body of saline water that covers approximately 72% of the Earth’s surface. According to NOAA, there is only one Global Ocean. However, this ocean has been divided into distinct named geographic regions by countries and oceanographers. Today, most nations including the United States recognizes five ocean basins, namely Arctic, Atlantic, Indian, Pacific, and Southern. Together, they hold around 97% of the water found on Earth and significantly influence global weather patterns and food supply chains. The ocean houses a plethora of marine organisms ranging from marine microbes to the world’s largest animal, the blue whale. However, although the ocean plays a major role in sustaining life on Earth, we have explored or mapped only about 20% of the ocean. The rest remains a mystery.

1. Arctic Ocean

A fisherman’s boat on the Arctic Ocean in Greenland. Image credit: Yongyut Kumsri/Shutterstock.com

The smallest, coldest, and shallowest of the oceans of the world, the Arctic Ocean is located in the Northern Hemisphere’s Arctic north polar region. The Arctic Ocean has a roughly circular basin that is nearly enclosed by the continental landmasses of North America, Eurasia, Greenland, and several smaller islands. The area occupied by the ocean is about 15,558,000 square km, and its coastline extends for 45,389 km. The maximum recorded depth is found to be 18,456 feet. The Bering Strait connects the Arctic Ocean to the Pacific Ocean. The Greenland Sea and the Labrador Sea forms the connection between this ocean and the Atlantic Ocean. The countries bordering the Arctic Ocean are the US, Canada, Iceland, Greenland, Norway, and Russia. Barrow and Prudhoe Bay in Alaska; Churchill, Nanisivik, and Inuvik in Canada; Nuuk in Greenland; Kirkenes, Vardø, and Longyearbyen in Norway; and several ports like Murmansk, Tiksi, and Pevek in Russia, all lie on the Arctic coast.

The Arctic Ocean is located in a polar climatic zone characterized by frigid year-round temperatures. Long hours of darkness engulf the ocean during winters and summers are characterized by continuous daylight. The marine habitat of the Arctic Ocean is a fragile ecosystem that is highly susceptible to slight disruptions in weather. Threatened species of whales and walruses inhabit the ocean. Plant life in the Arctic Ocean is scarce except for abundant volumes of phytoplanktons. The Lion’s mane jellyfish and the banded gunnel are among the few species of marine creatures inhabiting the Arctic Ocean’s waters. The ocean bed also hosts petroleum and natural gas fields, polymetallic nodules, and placer deposits.

Like other oceans of the world, climate change threatens to adversely affect the marine ecosystem of the Arctic Ocean. As per research, the Arctic might become ice-free by 2040. This transformation would load the Arctic with large volumes of meltwater and affect the ocean currents prevailing in the region. These alterations would, in turn, cause a drastic change in the global climate.

2. Atlantic Ocean

A Humpback whale (Megaptera novaengliae) raises its large fluke in the Atlantic Ocean. Image credit: Ethan Daniels/Shutterstock.com

The Atlantic Ocean spans an area of 85,133,000 square km. The Atlantic Ocean is bounded by the landmasses of North and South America to the west and Asia and Africa to the east. The Arctic Ocean lies to its north, the Southern Ocean to its south, Pacific to the southwest and Indian Ocean to the southeast. The average depth of the Atlantic Ocean is 3,646 m and the Milwaukee Deep (8,380 m) in the Puerto Rico Trench, is its deepest known point.

Since the Atlantic Ocean is vast, its climate varies widely from the north to the south. Warm and cold ocean currents in the Atlantic also influence the climate of the coastal areas on the shores of the Atlantic. The Gulf Stream and the North Atlantic Drift are responsible for keeping large parts of the coast of north-western Europe and the British Isles warm when the coast of Newfoundland in Canada on the same latitude experiences extreme temperatures in winter.

The Atlantic Ocean has contributed significantly to the economy of many nations. Petroleum deposits on the Atlantic’s floor, precious stones, placer deposits, and polymetallic nodules are abundant. The Atlantic also hosts rich fishing resources with haddock, cod, mackerel, herring being the chief commercially important fish species.

Several rare and threatened species of marine life like sea turtles, whales, dolphins, manatees, seals, sea lions abound in the Atlantic. Frequent oil spills, municipal sewage pollution, industrial pollution, bycatch during irresponsible and outdated fishing activities all threaten the marine life in the Atlantic Ocean.

3. Indian Ocean

The islands of Seychelles in the warm, tropical waters of the Indian Ocean. Image credit: GagliardiPhotography/Shutterstock.com

The Indian Ocean occupies 70,560,000 square km area on the Earth’s surface. The Eurasian landmass lies to the north of the Indian Ocean, Australia to the east, Africa to the west and the Southern Ocean and Antarctica to the south. 3,741 m is the average depth of the Indian Ocean, and its deepest point is Diamantina Deep. The depth in this region is 8,047 m.

The Indian Ocean region experiences a monsoon type of climate. Cyclones are common during the summer season. This ocean is also the warmest ocean in the world. The warm tropical waters of the ocean support a great diversity of life. The abundance of phytoplankton and aquatic flora supports a complex food chain. Thus, the Indian Ocean offers lucrative fishing grounds and fish, especially tuna and shrimp caught here, are sold to markets across the world. However, despite this great biodiversity, climate change is taking its toll on the Indian Ocean ecosystem. Overfishing in the waters is also disturbing the marine life in this part of the ocean.

4. Pacific Ocean

Aerial view of 70 islands in Palau in the Pacific Ocean. Image credit: BlueOrange Studio/Shutterstock.com

The largest region of the Global Ocean, the Pacific Ocean has the Arctic Ocean to the north, the Southern Ocean to the south, Australia, and Asia to the west and the Americas to the east. Spanning an area of 168,723,000 square km, the Pacific Ocean accounts for one-third of the total surface area of the planet. The deepest point in the Pacific Ocean is the Challenger Deep in the Mariana Trench (10,929 m) located in the western North Pacific.

Large parts of the Pacific remain unexplored due to its great depths. However, in the relatively shallow waters off the coast of Australia and New Zealand, petroleum and natural gas deposits have been discovered. Pearl extraction is also common in the Pacific’s waters. A large variety of fish like tuna, salmon, swordfish, herring, snapper, etc., abound in parts of the Pacific.

Today, the Pacific Ocean and its marine life are not safe. A large number of highly polluted rivers from the countries of southeast Asia and east Asia drain into this ocean, contaminating the waters with pollutants. Fertilizer and pesticide wash-off from agricultural fields, sewage, and industrial wastes all drain into the ocean via these rivers. Excess of oxygen depleting pollutants triggers hypoxia and creates dead zones in the ocean. Overfishing in the Pacific has also depleted its marine wealth greatly. A number of rare and threatened species is getting depleted in large numbers as bycatch.

5. Southern Ocean

Southern Ocean and Antarctic islands near the Antarctic Peninsula in winter. Image credit: Tarpan/Shutterstock.com

Encircling Antarctica, south of the 60° S latitude, is the Southern Ocean or the Antarctic Ocean. It is the southernmost of the 5 regions of the Global Ocean and the fourth largest of the five. Though the Southern Ocean does not have a landmass bordering it to the north, it is treated as a separate oceanic division due to the difference in water properties of the ocean south of the 60° S latitude. It is a deep ocean with depth ranging between 4,000 and 5,000 m across most parts.

Researchers estimate that the Southern Ocean seabed is a storehouse of massive oil and gas fields, valuable minerals like gold, placer deposits, manganese nodules, and more. The icebergs of the Southern Ocean are treated as freshwater resources, sufficient to feed every person on Earth for a period of several months. The Southern Ocean is also one of the most dangerous parts of the ocean for ships. Choppy seas, storms, and iceberg interventions are common. The remoteness also prevents rescue missions from reaching the ships in need.

The Southern Ocean is home to unique species specially adapted to survive the frigid weather conditions. Penguins, orcas, whales, seals, colossal squids are some of the most notable species of the Southern Ocean. A large number of migratory birds can be spotted in the oceanic region and Antarctica. These include terns, gulls, albatrosses, skuas, petrels, etc. Several threats are experienced by the marine inhabitants of the Southern Ocean. The Antarctic ozone hole in the ozone layer above allows harmful UV rays to reach the marine habitat, reducing phytoplankton by as much as 15%. Unregulated fishing also reduces the fish stock in the ocean which disturbs the food chain and affects the survival of the other species in the chain.

How many oceans are there in the world?

Since 2021, a new ocean has been added by cartographers, bringing the tally to five grand oceanic basins.

Maps exhibiting the world’s oceanic waters. A continuous body of water encircling Earth, the World/Global Ocean is divided into five main areas. Credit: Wikimedia Commons.

About 72% of our planet’s surface is covered by one huge global ocean that serves as the world’s largest habitat and helps regulate the global climate. But although Earth’s continents are surrounded by one single continuous body of water, this global ocean is formally divided into five ocean basins.

These oceans are classed as distinct because they encompass a distinct ecological region defined by ocean currents and temperatures, are almost enclosed by continents, or simply because of cultural or political considerations.

The world’s five oceans are the Pacific, Atlantic, Arctic, Indian, and Southern Oceans. Collectively, they stretch over 361,000,000 square kilometers (139,000,000 sq miles) and harbor over 230,000 known species of marine life. But since much of the ocean depths are unexplored, there could be up to two million species.

Although scientists have been referring to the icy waters around Antarctica as the Southern Ocean for many years, cartographers officially recognized it as unique only very recently, on June 8, 2021 (World Ocean Day). But the International Hydrographic Organization (IHO) had tried to settle the debate much earlier, through a 2000 publication that declared, named, and demarcated the Southern Ocean, also known as the Antarctic Ocean.

There are 68 member countries of the IHO, and twenty-eight countries responded to the IHO’s request for recommendations on what to do about the Southern Ocean. Eighteen of the 28 responding countries voted in favor of calling the ocean the Southern Ocean over the alternative name Antarctic Ocean.

The Pacific Ocean

The Pacific Ocean is, by far, the largest, deepest, and also the most biodiverse ocean out of the five. It spans over 165 million square kilometers from California to China, more than all of Earth’s landmasses put together.

The Pacific ocean was named by explorer Ferdinand Magellan in 1520, who originally called it Mare Pacificum, Latin for “peaceful sea”, as he sailed through its calm waters. But Magellan obviously only saw the gentle side of this giant ocean. In fact, the Pacific Ocean stirs up some of the strongest storms ever, including hurricanes, typhoons, and cyclones, thanks to the high energy of its warmer water.

Hurricanes, cyclones, and typhoons are actually all the same weather phenomenon, namely storms with wind speeds over 120 kilometers per hour (75 miles per hour). Hurricanes occur in the eastern Pacific, typhoons in the northwestern part of the ocean, and cyclones form in the southwestern Pacific.

Stretching across half the world, the Pacific’s water temperatures vary greatly from freezing in the poles to about 25-30°C (77-84°F) near the equator. Generally, the Pacific is significantly warmer than the Atlantic.

Salinity also varies with the latitude, with water near the equator being less salty than those at the mid-latitudes.

The surface circulation of waters in the Pacific is clockwise in the Northern Hemisphere, a movement called the North Pacific Gyre, and counter-clockwise in the Southern Hemisphere.

The Pacific is home to over 25,000 islands, including New Guinea, the second-largest island in the world. This large number of islands is owed to the basin’s rich volcanic activity around its edges, known as the “Ring of Fire”. Volcanoes form a 25,000-mile-long chain at the boundary where the Pacific tectonic plate slides against other neighboring plates. The same process also forms deepwater trenches, including the world’s deepest point, the Mariana Trench located east of the Philippines.

But the Pacific harbors all manners of records and superlatives, including the Great Pacific Garbage Patch, a testament to marine pollution on a grand scale. Sitting between Hawaii and California, the Great Pacific Garbage Patch stretches over an area larger than the state of Texas. The plastic pollution includes everything from discarded bottles to abandoned industrial fishing gear, but over 95% of the plastics from the patch are actually microplastics, tiny polymer bits smaller than a grain of sand that circulated through the waters and eventually make their way into the marine food web.

The Atlantic Ocean

The Atlantic is one of the youngest oceans, having formed long after the Pacific, Indian, and Arctic Oceans during the Triassic Period. Its name is derived from Greek mythology, the word Atlantikos meaning the Sea of Atlas, where Atlas was a titan responsible for standing on the edge of the world and holding up the heavens on his shoulders.

The ocean forms an elongated, S-shaped basin divided into the North Atlantic and South Atlantic by Equatorial Counter-Currents. The North and South Atlantic’s distinct ocean currents shape weather patterns around the world.

The distinctive shape of the Atlantic has a story behind it. If you ever wondered why the Atlantic coastlines of South America and Africa look like they fit together, it’s because they actually used to fit together on a giant geological jigsaw puzzle, a supercontinent called Gondwana that began to break up about 180 million years ago.

Covering close to 20% of the planet’s surface, the Atlantic is eclipsed in size only by the Pacific. You could fit the continental United States six and a half times inside this ocean. Its ocean floor is composed of the mid-Atlantic Ridge, a submerged mountain range extending all the way from Iceland to 58 degrees South in latitude, making it the longest mountain range in the world.

Its deepest point is found in the Milwaukee Deep in the Puerto Rico Trench, nearly eight kilometers (five miles) below the water’s surface, near the island of Puerto Rico.

The Arctic Ocean

The Arctic ocean is the smallest and northernmost ocean, embracing the Arctic Circle at the North Pole. Its most remarkable feature is its perennial (all-year) sea ice, which used to cover over half of the ocean, but this is changing at a frightening rate. The Arctic region is warming twice as fast as anywhere else on Earth due to man-made climate change, with important consequences for local wildlife.

Compared to the 1980s, the surface area of Arctic sea ice is down by 40%. By the late 2030s, the Arctic Ocean could become largely free of sea ice during the summers. This means that a once impenetrable natural barrier could soon become open to large-scale commercial shipping and fossil fuel exploration — something that we’re already seeing now. Even tourists are now flocking to this otherworldly landscape, a trip that used to be usually reserved for daring explorers, researchers, and fishermen.

Under its frigid water, the Arctic is teeming with life, from tiny plankton to large bowhead whales. On the sea ice itself, polar bears and walruses can be seen roaming. But warming waters are likely to hurt the entire food chain. For instance, warm waters impact the zooplankton life cycles, and by extension the myriad of animals that prey on them, while terrestrial animals like polar bears will find it difficult to find food as they rely on sea ice to traverse the landscape.

The greatest inflow of water comes from the Atlantic by way of the Norwegian Current, which then flows along the Eurasian coast. Water also enters from the Pacific via the Bering Strait. Further modified by river inputs and the freezing and melting of sea ice, the Arctic Ocean exports modified waters back into the North Atlantic, thus impacting the global thermohaline circulation.

The Indian Ocean

The Indian Ocean covers approximately one-fifth of the world’s total ocean cover. It’s the smallest and youngest ocean of the world’s three major oceans (the others being the Pacific and Atlantic), but don’t let its junior status fool you — the Indian Ocean is perhaps more physically complex than the Pacific and Atlantic.

Like the Atlantic, the Indian Ocean formed around 180 million years ago as a consequence of the breakup of the southern tip of the supercontinent Gondwana. By 36 million years ago, the Indian Ocean attained its present configuration, bounded by the Indian subcontinent towards the north, Africa towards the west, The Sunda Islands and Australian lands towards the east, and Antarctica towards the south.

Climate-wise, the Indian Ocean can be subdivided into four general latitudinal climatic zones based on atmospheric circulation: monsoon, trade winds, subtropical and temperate. It also has subantarctic and Antarctic areas. Although it borders Antarctica to the south, the Indian Ocean is the warmest ocean in the world.

As a consequence of the high water temperature, not much marine life can be found as the conditions aren’t optimal for the growth of plankton, the bottom of the food web, which all other marine life depends on. The challenge for life is compounded by the fact that the Indian Ocean has the lowest oxygen content in the world due to the higher evaporation rate.

The Southern Ocean

Also known as the Antarctic Ocean, the Southern Ocean is the most southerly of the world’s five great oceans.

For decades, geographers have been debating whether the waters that surround Antarctica had enough unique characteristics to deserve a designation of their own as a full-fledged oceanic basin. Some claim this body of water is simply a colder, southern extension of the Pacific, Atlantic, and Indian Oceans. But in 2021, the National Geographic Society made a cartographic update, siding with scholars who viewed the Antarctic waters as a distinct ocean.

Most other oceans are defined by the continents that border them. For instance, the Atlantic is bound by the Americas to the west and by Europe and Africa to the east. But the Southern Ocean is primarily defined by its currents, such as the Antarctic Circumpolar Current, which flows from west to east around the icy continent. Inside this current, the waters are much colder and slightly less salty than the oceans further to the north.

The Antarctic Circumpolar Current has a profound impact on Earth’s climate and weather system. It pulls waters from the warm Atlantic, Pacific, and Indian Oceans, thereby transporting heat around the planet through a global circulation system that scientists commonly refer to as “the conveyor belt”.

Although it’s not warming as fast as the Arctic, the Southern Ocean is one of the most rapidly warming areas of the world. The higher temperatures and lower oxygen availability may severely impact Antarctic fish by affecting the life cycles of krill — the major food source for many Antarctic fish species — leading them to migrate to cooler, more oxygenated water.

Understanding the present state of Antarctic waters is essential to forecasting the changes that will occur in the near future and predicting the impacts on Antarctic food webs and biogeochemical cycles.

Do the oceans have real boundaries?

In the same way that all of Earth’s present-day continents were once part of a single, massive continent called Pangaea, so do all the oceans belong to a single world ocean — which, during the age of Pangaea, was called Panthalassa. In fact, the same can be said about the rest of the smaller seas, such as the Mediterranean or the Black Sea, which are connected through straits or simply by open currents with the rest of the oceanic basins. The fact that the world’s oceanic waters constitute one global, interconnected body of salt water is of fundamental importance to oceanography.

Much like we classified the continents, oceans are designated based on geographical and physical criteria, but also on political and cultural considerations. As such, the boundaries that separate these bodies of water are arbitrary, largely defined by the continents that frame them. Water properties, ocean currents, and biological populations are not necessarily constrained by these boundaries, although they may be distinct to one or more regions of the World Ocean. But, for now, until the continents finish their next big move or until ocean scientists discover something world-changing, we recognize 5 oceans.

How Many Oceans Are There in the World?

Today our question is “How many Oceans Are There in the World? “. There are 5 major oceans in the world. If we contains the ancient oceans there are 19 oceans in the world.

What is Ocean
Ocean : The vast body of salt water that covers almost three fourths of the earth’s surface. Dictionary

Ocean : The whole body of salt water that covers nearly three fourths of the surface of the earth. Merriam

Ocean : An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth’s surface (

3.6×108 km2 ) is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas. More than half of this area is over 3,000 meters (9,800 ft) deep. Average oceanic salinity is around 35 parts per thousand (‰) (3.5%), and nearly all seawater has a salinity in the range of 30 to 38 ‰. Scientists estimate that 230,000 marine species are currently known, but the total could be up to 10 times that number. Wikipedia

There are five major oceans of the world,

Ancient oceans include:

Just How Many Oceans Are There?

Notwithstanding that Europa and Enceladus (moons of Jupiter and Saturn, respectively) are both covered in ice, Earth is the true water world of the solar system. Some 71 percent of Earth’s surface is covered by saltwater oceans, and the continents themselves possess lakes, rivers, and, in some cases, seas. The largest bodies of water are the oceans, but there is some debate over the actual number of distinct oceans. Just how many oceans does our planet have?

Historically, many maps and textbooks have presented a four-ocean model: the Pacific, the Atlantic, the Indian, and the Arctic. The first three are the major ones, while the Arctic Ocean tends to be less prominent in people’s minds. Perhaps that’s because it’s far smaller than the others, occurs on the fringes of the map, and tends to be covered (well, partly covered) by ice.

In reality, however, Earth’s ocean count depends on one’s perspective. A collection of scientific organizations, the International Hydrographic Organization (IHO), and many national governments note the existence of a fifth ocean, the Southern Ocean (also called the Antarctic Ocean), consisting of the waters surrounding Antarctica below 60° S latitude, although the IHO’s member countries do not agree on the ocean’s formal borders. Separating the Southern Ocean from the Atlantic, Pacific, and Indian oceans seems reasonable when one considers that the Antarctic Circumpolar Current and the winds that circle the outer approaches of the continent create a kind of natural separation, the Antarctic Convergence (in terms of oceanography and meteorology), between Antarctica and the rest of the world. In June 2021 the Southern Ocean’s status received a new boost when this body of water was officially recognized by the National Geographic Society (an American not-for-profit research and educational organization that has a long-standing tradition of serious mapmaking). Regardless of that announcement, the boundaries of the Southern Ocean were still not accepted universally.

Functionally speaking, there is really only one ocean, since every demarcated ocean is connected to at least two others. The reality of a single continuous ocean is also evidenced by thermohaline circulation (also called the Global Ocean Conveyor or the Great Ocean Conveyor Belt), which transports seawater through all the named oceans. Thermohaline circulation continually replaces water at depth with water from the surface and slowly replaces surface water elsewhere with water rising from deeper depths.