Covers approximately 360,000,000 km² and is generally divided into several major oceans and smaller seas, with oceans covering approximately 71% of the Earth's surface and 90% of the Earth's biosphere.

They contain 97% of the Earth's water, and oceanographers claim that only 5% of the ocean depths have been explored.

In contact with

Since the world's oceans are the main component of the Earth's hydrosphere, they are an integral part of life, form part of the carbon cycle, and influence climate and weather patterns. It is also home to 230,000 known animal species, but since most of them are unexplored, the number of underwater species is probably much higher, perhaps over two million.

The origin of the oceans on Earth is still unknown.

How many oceans on earth: 5 or 4

How many oceans are there in the world? For many years, only 4 were officially recognized, and then in the spring of 2000, the International Hydrographic Organization established the Southern Ocean and defined its limits.

It is interesting to know: what continents exist on planet Earth?

The oceans (from the ancient Greek Ὠκεανός, Okeanos) make up most of the planet's hydrosphere. In descending order by area, there are:

• Quiet.
• Atlantic.
• Indian.
• Southern (Antarctic).
• Arctic Oceans (Arctic).

Earth's global ocean

Although several separate oceans are usually described, the global, interconnected body of salt water is sometimes referred to as the World Ocean. TO the concept of continuous water with relatively free exchange between its parts is fundamental to oceanography.

The major oceanic spaces, listed below in descending order of area and volume, are partly determined by continents, various archipelagos, and other criteria.

What are the oceans, their location

Quiet, the largest, extends north from the Southern Ocean to the North. It spans the gap between Australia, Asia and America and meets the Atlantic just south of South America at Cape Horn.

The Atlantic, the second largest, stretches from the Southern Ocean between America, Africa and Europe to the Arctic. It meets the Indian Ocean south of Africa at Cape Agulhas.

Indian, the third largest, extends north from the Southern Ocean to India, between Africa and Australia. It flows into the Pacific expanses in the east, near Australia.

The Arctic Ocean is the smallest of the five. It joins the Atlantic near Greenland and Iceland and the Pacific Ocean at the Bering Strait and spans the North Pole, touching North America in the Western Hemisphere, Scandinavia and Siberia in the Eastern Hemisphere. Almost all of it is covered with sea ice, the extent of which varies depending on the season.

Southern - surrounds Antarctica, where the Antarctic circumpolar flow prevails. This maritime space has only recently been identified as a separate oceanic unit, which is located south of sixty degrees south latitude and is partially covered by sea ice, the size of which depends on the season.

They are bordered by small adjoining reservoirs. such as seas, bays and straits.

Physical Properties

The total mass of the hydrosphere is about 1.4 quintillion metric tons, which is about 0.023% of the Earth's total mass. Less than 3% - fresh water; the rest is salt water. The ocean area is about 361.9 million square kilometers and covers about 70.9% of the Earth's surface, and the volume of water is about 1.335 billion cubic kilometers. The average depth is about 3,688 meters and the maximum depth is 10,994 meters in the Mariana Trench. Almost half of the world's sea waters are over 3,000 meters deep. Huge spaces below 200 meters deep cover about 66% of the Earth's surface.

The bluish color of the water is a constituent of several contributing agents. Among them are dissolved organic matter and chlorophyll. Sailors and other sailors have reported that ocean waters often emit a visible glow that extends for miles at night.

oceanic zones

Oceanographers divide the ocean into different vertical zones determined by physical and biological conditions. Pelagic zone includes all zones and can be divided into other areas, divided by depth and illumination.

The photic zone includes surfaces down to a depth of 200 m; it is an area where photosynthesis takes place and is therefore highly biodiverse.

Because plants require photosynthesis, life found deeper than the photon zone must either rely on material descending from above or find another energy source. Hydrothermal vents are the main source of energy in the so-called aphotic zone (more than 200 m deep). The pelagic part of the photon zone is known as the epipelagic.

Climate

Cold deep water rises and warms in the equatorial zone, while thermal water sinks and cools near Greenland in the North Atlantic and near Antarctica in the South Atlantic.

Ocean currents strongly influence the Earth's climate, transferring heat from the tropics to the polar regions. By transferring warm or cold air and precipitation to coastal regions, winds can carry it inland.

Conclusion

Many of the world's goods are moved by ship between the world's seaports. Ocean waters are also the main source of raw materials for the fishing industry.

The second name of the Earth, "the blue planet", did not appear by chance. When the first astronauts saw the planet from space, it appeared to them in this color. Why does the planet appear blue instead of green? Because 3/4 of the Earth's surface is the blue waters of the oceans.

World Ocean

The World Ocean is the water shell of the Earth that surrounds the continents and islands. Its largest parts are called oceans. There are only four oceans: , , , .

And more recently, they began to allocate more and.

The average depth of the water column in the World Ocean is 3700 meters. The deepest point is in the Mariana Trench - 11,022 meters.

Pacific Ocean

Pacific Ocean, the largest among all four, got its name due to the fact that at the time when the sailors led by F. Magellan crossed it, it was surprisingly quiet. The second name of the Pacific Ocean is Great. It is really great - it accounts for 1/2 of the waters of the World Ocean, the Pacific Ocean occupies 2/3 of the earth's surface.

Coast of the Pacific Ocean near Kamchatka (Russia)

The waters of the Pacific Ocean are amazingly clean and transparent, most often dark blue, but sometimes green. The degree of salinity of the water is medium. Most of the time, the ocean is calm and calm, with a moderate wind blowing over it. There are almost no hurricanes here. Above the Great and Quiet there is always a clear starry sky.

Atlantic Ocean

Atlantic Ocean- the second largest after the Pacific. The origin of its name still raises questions from scientists around the world. According to one version, the Atlantic Ocean was named after the titan Atlanta, a representative of Greek mythology. Supporters of the second hypothesis argue that it owes its name to the Atlas Mountains located in Africa. Representatives of the "youngest", third version, believe that the Atlantic Ocean is named after the mysterious disappeared mainland Atlantis.

The Gulf Stream on a map of the Atlantic Ocean.

The degree of salinity of ocean waters is the highest. Flora and fauna are the richest, scientists still find the most interesting specimens unknown to science. In its cold part, such interesting representatives of the fauna as whales and pinnipeds live. In warm waters, sperm whales and seals can be found.

The uniqueness of the Atlantic Ocean is that it, more precisely, its warm Gulf Stream, jokingly called the main European “furnace”, is “responsible” for the climate of the entire Earth.

Indian Ocean

The Indian Ocean, in which many rare specimens of flora and fauna can be found, ranks third in size. In it, according to researchers, navigation began about 6 thousand years ago. The first navigators were the Arabs, they also made the first maps. It was once explored by Vasco de Gama, James Cook.

The underwater world of the Indian Ocean attracts divers from all over the world.

The waters of the Indian Ocean, clean, transparent and amazingly beautiful due to the fact that few rivers flow into it, can be dark blue and even azure.

Arctic Ocean

The smallest, coldest and least studied of all five parts of the World Ocean is located in the Arctic. The ocean began to be explored only from the 16th century, when navigators wanted to find the shortest route to the rich eastern countries. The average depth of ocean waters is 1225 meters. The maximum depth is 5527 meters.

The consequences of global warming are the melting of glaciers in the Arctic. A warm current carries a detached layer of ice with polar bears to the Arctic Ocean.

The Arctic Ocean is of great interest to Russia, Denmark, Norway, Canada, as its waters are rich in fish, and the subsoil is rich in natural resources. Seals are found here, birds arrange noisy “bird markets” on the shores. A characteristic feature of the Arctic Ocean is that ice floes and icebergs drift on its surface.

South ocean

In 2000, scientists managed to prove that there is a fifth of the oceans. It is called the Southern Ocean and includes the southern parts of all those oceans, except for the Arctic Ocean, which wash the shores of Antarctica. This is one of the most unpredictable parts of the oceans. The Southern Ocean is characterized by changeable weather, strong winds, and cyclones.

The name "Southern Arctic Ocean" has been found on maps since the 18th century, but on modern maps the Southern Ocean began to be marked only in this century - just a decade and a half ago.

The oceans are huge, many of its mysteries have not yet been solved, and who knows, maybe you will solve some of them?

World Ocean- the main part of the hydrosphere, a continuous, but not continuous, water shell of the Earth, surrounding the continents and islands and characterized by a common salt composition. The world ocean is a heat regulator. The world ocean has the richest food, mineral and energy resources. Although the World Ocean is a single whole, for the convenience of research, its individual parts have been given different names: the Pacific, Atlantic, Indian, Arctic Oceans and the South.

Ocean and atmosphere. The oceans, the average depth of which is approx. 4 km, contains 1350 million km3 of water. The atmosphere, enveloping the entire Earth in a layer several hundred kilometers thick, with a much larger base than the World Ocean, can be considered as a "shell". Both the ocean and the atmosphere are the fluids in which life exists; their properties determine the habitat of organisms. The ocean determines the main properties of the atmosphere and is a source of energy for many processes occurring in the atmosphere. The circulation of water in the ocean is affected by winds, the rotation of the Earth, and land barriers.

Ocean and climate. It is well known that the temperature regime and other climatic characteristics of the area at any latitude can change significantly in the direction from the ocean coast to the interior of the mainland. Compared to land, the ocean heats up more slowly in summer and cools more slowly in winter, smoothing out temperature fluctuations on adjacent land.

Composition of sea water. The ocean water is salty. The salty taste is given by the 3.5% dissolved minerals contained in it - mainly sodium and chlorine compounds - the main ingredients of table salt. Magnesium is next in number, followed by sulfur; all common metals are also present. Of the non-metallic components, calcium and silicon are especially important, since they are involved in the structure of the skeletons and shells of many marine animals. Due to the fact that the water in the ocean is constantly mixed by waves and currents, its composition is almost the same in all oceans.

properties of sea water. The density of sea water (at a temperature of 20 ° C and salinity approx. 3.5%) is approximately 1.03, i.e. slightly higher than the density of fresh water (1.0). The density of water in the ocean varies with depth due to the pressure of the overlying layers, as well as depending on temperature and salinity. In the deepest parts of the ocean, the waters tend to be saltier and colder. The densest masses of water in the ocean can remain at depth and maintain a lower temperature for more than 1000 years.

Sea water is much less transparent to visible light than air, but more transparent than most other substances. Recorded penetration of sunlight into the ocean to a depth of 700 m. Radio waves penetrate into the water column only to a shallow depth, but sound waves can propagate under water for thousands of kilometers. The speed of sound propagation in sea water fluctuates, averaging 1500 m per second.

Nearly 95% of all water on Earth is salty and unusable. It consists of seas, oceans and salt lakes. Collectively, all this is called the World Ocean. Its area is three-quarters of the entire area of ​​the planet.

The oceans - what is it?

The names of the oceans have been familiar to us since elementary school. This is the Pacific, otherwise called the Great, Atlantic, Indian and Arctic. All of them together are called the World Ocean. Its area is more than 350 million km2. This is the largest area even on a planetary scale.

The continents divide the World Ocean into four oceans known to us. Each of them has its own characteristics, its own unique underwater world, which changes depending on the climatic zone, the temperature of the currents and the bottom topography. The map of the oceans shows that they are all interconnected. None of them is surrounded by land on all sides.

The science that studies the oceans is oceanology

How do we know that there are seas and oceans? Geography is a school subject that introduces us to these concepts for the first time. But a special science, oceanology, is engaged in a deeper study of the oceans. It considers water expanses as an integral natural object, studies the biological processes occurring inside it, and its relationship with other constituent elements of the biosphere.

This science studies the ocean depths in order to achieve the following goals:

• increasing the efficiency and ensuring the safety of underwater and surface navigation;
• optimization of the use of minerals from the ocean floor;
• maintaining the biological balance of the oceanic environment;
• improvement of meteorological forecasts.

How did the modern names of the oceans come about?

The name of each geographical object is given for a reason. Any name has certain historical background or is associated with the characteristic features of a particular territory. Let's find out when and how the names of the oceans originated and who came up with them.

• Atlantic Ocean. The works of the ancient Greek historian and geographer Strabo described this ocean, calling it Western. Later, some scientists called it the Hesperid Sea. This is confirmed by a document dated 90 BC. Already in the ninth century AD, Arab geographers voiced the name "Sea of ​​Darkness", or "Sea of ​​Darkness". It received such a strange name because of the clouds of sand and dust that the winds raised above it, constantly blowing from the African continent. For the first time, the modern name sounded in 1507, after Columbus reached the shores of America. Officially, such a name was fixed in geography in 1650 in the scientific works of Bernhard Waren.
• The Pacific Ocean was named so by the Spanish navigator. Despite the fact that it is quite stormy and there are often storms and tornadoes, during the expedition of Magellan, which lasted a year, the weather was always good, calm was observed, and this was the reason to think that the ocean was really quiet and calm. When the truth was revealed, no one began to rename the Pacific Ocean. In 1756, the explorer Bayush suggested calling it the Great, since it is the largest ocean of all. To this day, both of these names are used.
• The reason for giving the name was the many ice floes drifting in its waters, and, of course, the geographical location. His second name - Arctic - comes from the Greek word "arktikos", which means "northern".
• With the name of the Indian Ocean, everything is extremely simple. India is one of the first countries known to the ancient world. The waters that wash its banks were named after her.

four oceans

How many oceans are on the planet? This question seems to be the simplest, but for many years it has caused discussions and disputes among oceanologists. The standard list of oceans looks like this:

2. Indian.

3. Atlantic.

4. Arctic.

But since ancient times, there has been another opinion, according to which the fifth ocean stands out - the Antarctic, or the South. Arguing for such a decision, oceanologists cite as evidence the fact that the waters washing the shores of Antarctica are very peculiar and the system of currents in this ocean differs from the rest of the water expanses. Not everyone agrees with this decision, so the problem of dividing the World Ocean remains relevant.

The characteristics of the oceans are different depending on many factors, although it may seem that they are all the same. Let's get acquainted with each of them and find out the most important information about all of them.

Pacific Ocean

It is also called the Great, because it has the largest area among all. The Pacific Ocean basin occupies a little less than half the area of ​​​​all the world's water spaces and is equal to 179.7 million km².

The composition includes 30 seas: Japan, Tasmanovo, Javanese, South China, Okhotsk, Philippine, New Guinea, Savu Sea, Halmahera Sea, Koro Sea, Mindanao Sea, Yellow, Visayan Sea, Aki Sea, Solomonovo, Bali Sea, Samair Sea, Coral, Banda, Sulu, Sulawesi, Fiji, Moluckoe, Komotes, Seram Sea, Flores Sea, Sibuyan Sea, East China Sea, Bering Sea, Amudesena Sea. All of them occupy 18% of the total area of ​​the Pacific Ocean.

It is also the leader in terms of the number of islands. There are about 10 thousand of them. The largest islands in the Pacific Ocean are New Guinea and Kalimantan.

The subsoil of the seabed contains more than a third of the world's natural gas and oil reserves, the active production of which occurs mainly in the shelf zones of China, the United States of America and Australia.

There are many transport routes across the Pacific Ocean connecting the countries of Asia with South and North America.

Atlantic Ocean

It is the second largest in the world, and this is clearly demonstrated by the map of the oceans. Its area is 93,360 thousand km2. The Atlantic Ocean basin contains 13 seas. All of them have a coastline.

An interesting fact is that in the middle of the Atlantic Ocean there is the fourteenth sea - Sargasovo, called the sea without coasts. Its boundaries are ocean currents. It is considered the largest sea in the world in terms of area.

Another feature of this ocean is the maximum inflow of fresh water, which is provided by the large rivers of North and South America, Africa and Europe.

In terms of the number of islands, this ocean is the exact opposite of the Pacific. There are very few of them here. But it is in the Atlantic Ocean that the largest island of the planet - Greenland - and the most remote island - Bouvet - are located. Although sometimes Greenland is ranked among the islands of the Arctic Ocean.

Indian Ocean

Interesting facts about the third largest ocean will make us wonder even more. The Indian Ocean was the first known and explored. He is the custodian of the largest complex of coral reefs.

The waters of this ocean hold a secret that has not yet been properly explored. The fact is that luminous circles of the correct form periodically appear on the surface. According to one version, this is the glow of plankton rising from the depths, but their ideal spherical shape is still a mystery.

Not far from the island of Madagascar, you can observe a one-of-a-kind natural phenomenon - an underwater waterfall.

Now some facts about the Indian Ocean. Its area is 79,917 thousand km2. The average depth is 3711 m. It washes 4 continents and has 7 seas. Vasco da Gama is the first explorer to swim across the Indian Ocean.

Interesting facts and characteristics of the Arctic Ocean

It is the smallest and coldest of all oceans. Area - 13,100 thousand km 2. It is also the shallowest, the average depth of the Arctic Ocean is only 1225 m. It consists of 10 seas. By the number of islands, this ocean ranks second after the Pacific.

The central part of the ocean is covered with ice. In the southern regions, floating ice floes and icebergs are observed. Sometimes you can find whole ice 30-35 m thick. It was here that the infamous Titanic crashed, colliding with one of them.

Despite the harsh climate, the Arctic Ocean is a habitat for many species of animals: walruses, seals, whales, gulls, jellyfish and plankton.

depth of the oceans

We already know the names of the oceans and their features. But what is the deepest ocean? Let's look into this issue.

The contour map of the oceans and the ocean floor shows that the bottom relief is as diverse as the relief of the continents. Under the thickness of the sea water, deepenings, depressions and elevations like mountains are hidden.

The average depth of all four oceans taken together is 3700 m. The Pacific Ocean is considered the deepest, the average depth of which is 3980 m, followed by the Atlantic - 3600 m, followed by the Indian - 3710 m. The last in this list, as already mentioned, is the Arctic Ocean, the average depth of which is only 1225 m.

Salt is the main feature of ocean waters

Everyone knows how the water of the seas and oceans differs from fresh river water. Now we will be interested in such a characteristic of the oceans as the amount of salt. If it seems to you that the water is equally salty everywhere, you are very much mistaken. Salt concentrations in ocean waters can vary greatly, even within a few kilometers.

The average salinity of ocean waters is 35 ‰. If we consider this indicator separately for each ocean, then the Arctic Ocean is the least salty of all: 32 ‰. Pacific Ocean - 34.5 ‰. The salt content in the water is low here due to the large amount of precipitation, especially in the equatorial zone. Indian Ocean - 34.8‰. Atlantic - 35.4 ‰. It is important to note that bottom waters have a lower salt concentration than surface waters.

The most salty seas of the World Ocean are the Red (41 ‰), the Mediterranean Sea and the Persian Gulf (up to 39 ‰).

World ocean records

• The deepest place in the World Ocean is its depth of 11,035 m from the surface water level.
• If we consider the depth of the seas, then the Philippine sea is considered the deepest. Its depth reaches 10,540 m. The second place in this indicator is the Coral Sea with a maximum depth of 9140 m.
• The largest ocean is the Pacific. Its area is larger than the area of ​​the entire earth's land.
• The most salty sea is the Red Sea. It is located in the Indian Ocean. Salt water well supports all objects that fall into it, and it takes a lot of effort to drown in this sea.
• The most mysterious place is located in the Atlantic Ocean, and its name is the Bermuda Triangle. It is associated with many legends and mysteries.
• The most poisonous sea creature is the blue-ringed octopus. He lives in the Indian Ocean.
• The largest accumulation of corals in the world - the Great Barrier Reef, is located in the Pacific Ocean.

A favorite question of all geography teachers: "How many oceans are there on Earth?" In this case, you can answer in different ways, having understood in more detail the structure of the hydrosphere of our planet. The water shell is the key to life and prosperity on Earth, so every person should be at least superficially familiar with the processes that take place in it. This article will tell about this and many other interesting facts about the hydrosphere.

After long observations, all the scientists of the world came to the conclusion that the answer to the question of how many oceans there are on Earth will be unambiguous - four. If you turn to the history of the study of the hydrosphere, you will see that it was the first to be discovered. It is rightfully considered the warmest on Earth, because in summer, near the coasts, its waters can warm up to a record temperature of 35˚С.

After a trip that tried to find a way to India - the most attractive country for Europeans of that time - mankind learned about a new large water body. In honor of the Greek titan Atlanta, whom mythology endowed with a tough temper and courage, the ocean was given the name Atlantic. This body of water fully justifies the comparison with the hero of the myth, because at different times of the year it can behave completely unpredictably.

How many oceans are there on Earth? Among the previously unnamed, there were two: Pacific and Arctic. in fact, it got its name by mistake, since Magellan was very lucky with the weather during his trip around the world. As a result, the explorer thought that the ocean has a meek disposition, but this is far from the case. Tsunamis often occur off the western coast of North America and near.

The Arctic Ocean is the calmest of the largest bodies of water on our planet, and also the coldest. There are not many fish and plants in its waters, because not all representatives of the flora and fauna can withstand the harsh living conditions in it.

There was a period when some scientists answered the question: “How many oceans are there on Earth?” - answered: "Five". They identified another body of water that washes the shores of Antarctica. It was given the name South, but its boundaries are so indistinct that over time, the compilers of geographical maps ceased to designate this ocean.

This is well-known information about how many oceans there are on Earth. Many space researchers believe that the hydrosphere could be on other planets in the solar system. So, for example, scientists around the world are asking the question: “How many oceans on the planet Mars once existed?” They have not yet found an answer, but if the hydrosphere was still there, then, most likely, living organisms could also live on a neighboring planet millions of years ago.

The world ocean forms a continuous chain on our planet, the components of which are all of the above. It is the source of life, so humanity must protect such an important resource as clean water. Thanks to the competent distribution of these reserves, people guarantee themselves a normal existence, as well as a decrease in the likelihood of various natural disasters.