Oceans are the largest bodies of water that make up the bulk of the world's water resources. These objects are located between continents, having their own system of currents and other features. Each ocean constantly interacts with land, earth's crust and atmosphere. These bodies of water are studied by a special science called oceanology.
Global reserves of salt water contained in the oceans make up a significant portion of the hydrosphere. Ocean waters are not a continuous shell washing the planet. They surround land areas of different sizes - continents, archipelagos and individual islands. All the earth's ocean waters are usually divided into parts, taking into account the relative positions of the continents. Separate parts of the oceans form seas and bays.
How many oceans are there on the planet?
Currently, most experts tend to distinguish five oceans on Earth: Indian, Pacific, Atlantic, Arctic and Southern. But before there were only four of them. The fact is that not everyone and oceanologists still recognize the existence of a separate Southern Ocean, which is also called the Antarctic Ocean. This huge reservoir of water surrounds Antarctica, and its border is most often conventionally drawn along the sixtieth parallel of southern latitude.
The title of the largest rightfully belongs to the Pacific Ocean, whose area is almost 180 million square meters. km. This is where the deepest place on the planet is located - Mariana Trench. Its depth is 11 km. The Pacific Ocean, washing the shores of East Asia, Australia, North and South America, is distinguished by an abundance of islands, most of which are located in the west and center.
The second largest in size is the Atlantic Ocean. In terms of water area, it is approximately two times smaller than the Quiet. The waters of the Atlantic wash Europe, part of Africa, the eastern regions of the two American continents, and in the north Iceland and Greenland. The Atlantic Ocean is extremely rich in commercial fish and underwater vegetation.
The Indian Ocean is slightly smaller in size than the Atlantic. As its name suggests, it is located near India, also washing the eastern shores of Africa, the western edge of Australia and Indonesia. This ocean contains very big number seas.
The Arctic Ocean is the least explored. Its area is just over 14 million square meters. km. This water basin is located in the inaccessible northern part of the planet. Almost all year round Its surface is covered with thick ice. The lack of light and oxygen in the water depths led to the scarcity of flora and fauna in this ocean.
Traditional geography taught that there are four oceans in the world - the Pacific, Atlantic, Arctic and Indian.
However, just recently…-.
... - in 2000, the International Hydrographic Organization united the southern parts of the Atlantic, Indian and Pacific oceans, creating the fifth addition to the list - the Southern Ocean. And this is not a volitional decision: this region has a special structure of currents, its own rules of weather formation, etc. The arguments in favor of such a decision are as follows: in the southern part of the Atlantic, Indian and Pacific oceans, the boundaries between them are very arbitrary, while at the same time the waters adjacent to Antarctica, have their own specifics, and are also united by the Antarctic Circumpolar Current.
The largest of the oceans is the Pacific. Its area is 178.7 million km2. It is also the deepest ocean: in the Mariana Trench, which extends from the southeast of Guam to the northwest of the Mariana Islands, its depth reaches 11,034 m. The highest seamount in the Pacific Ocean is Mauna Kea. It rises from the ocean floor and protrudes above the surface of the water in the Hawaiian Islands. Its height is 10,205 m, that is, it is higher than even the highest mountain in the world, Mount Everest, although its peak rises only 4,205 m above sea level.
The Atlantic Ocean extends over 91.6 million km 2.
The area of the Indian Ocean is 76.2 million km2.
The area of the Antarctic (Southern) Ocean is 20.327 million km 2.
The Arctic Ocean covers an area of approximately 14.75 million km2.
Pacific Ocean, the largest on Earth. It was named so by the famous navigator Magellan. This traveler was the first European to successfully cross the ocean. But Magellan was just very lucky. There are very often terrible storms here.
The Pacific Ocean is twice the size of the Atlantic. It occupies 165 million square meters. km, which is almost half the area of the entire World Ocean. It contains more than half of all the water on our planet. In one place, this ocean extends 17 thousand km in width, stretching across almost half of globe. Despite its name, this huge ocean is not only blue, beautiful and serene. Strong storms or underwater earthquakes make him furious. In fact, on the territory Pacific Ocean There are large zones of seismic activity.
Photographs of the Earth from space show the true size of the Pacific Ocean. This is the largest ocean in the world, covering one third of the planet's surface. Its waters stretch from East Asia and Africa to the Americas. At its shallowest points, the depth of the Pacific Ocean averages 120 meters. These waters wash the so-called continental shelves, which are submerged parts of continental platforms, starting from the coastline and gradually going under water. Overall, the depth of the Pacific Ocean averages 4,000 meters. The depressions in the west connect to the deepest and dark place in the world - Mariana Trench - 11,022 m. Previously, it was believed that there was no life at such a depth. But scientists found living organisms there too!
The Pacific Plate, a huge area of the Earth's crust, contains ridges of high seamounts. In the Pacific Ocean there are many islands of volcanic origin, for example Hawaii, the largest island of the Hawaiian Islands archipelago. Hawaii is home to the highest peak in the world, Mauna Kea. It is an extinct volcano 10,000 meters high from its base on the seabed. In contrast to volcanic islands, there are low-lying islands formed by coral deposits that have been deposited over thousands of years on the tops of underwater volcanoes. This vast ocean is home to a wide variety of underwater species - from the world's largest fish (whale shark) to flying fish, squid and sea lions. The warm, shallow waters of coral reefs are home to thousands of species of brightly colored fish and algae. All kinds of fish, marine mammals, mollusks, crustaceans and other creatures swim in the cool, deep waters.
Pacific Ocean - people and history
Sea voyages across the Pacific Ocean have been undertaken since ancient times. About 40,000 years ago, Aboriginal people crossed by canoe from New Guinea to Australia. Centuries later between the 16th century BC. e. and X century AD e. Polynesian tribes settled the Pacific islands, venturing across vast distances of water. This is considered one of the greatest achievements in the history of navigation. Using special canoes with a double bottom and sails woven from leaves, Polynesian sailors ultimately covered almost 20 million square meters. km of ocean space. In the western Pacific, around the 12th century, the Chinese made great advances in the art of sea navigation. They were the first to use large ships with multiple underwater masts, steering, and compasses.
Europeans began exploring the Pacific Ocean in the 17th century, when the Dutch captain Abel Janszoon Tasman sailed around Australia and New Zealand. Captain James Cook is considered one of the most famous explorers of the Pacific Ocean. Between 1768 and 1779 he mapped New Zealand, the east coast of Australia and many of the Pacific islands. In 1947 Norwegian traveler Thor Heyerdahl sailed on his raft “Kon-Tiki” from the coast of Peru to the Tuamotu archipelago, part of French Polynesia. His expedition provided evidence that the ancient indigenous inhabitants of South America could cross vast sea distances on rafts.
In the twentieth century, exploration of the Pacific Ocean continued. The depth of the Mariana Trench was established, and unknown species of marine animals and plants were discovered. Development of the tourism industry, pollution environment and beach development threaten the natural balance of the Pacific Ocean. Governments individual countries and environmental groups are trying to minimize the damage our civilization causes to the aquatic environment.
Indian Ocean
Indian Ocean is the third largest on Earth and covers 73 million square meters. km. This is the warmest ocean, the waters of which are rich in various flora and fauna. The deepest place in the Indian Ocean is a trench located south of the island of Java. Its depth is 7450 m. Interestingly, currents in the Indian Ocean change their direction to the opposite direction twice a year. IN winter time When the monsoons prevail, the current goes to the shores of Africa, and in the summer - to the shores of India.
The Indian Ocean stretches from the coast of East Africa to Indonesia and Australia and from the coast of India to Antarctica. This ocean includes the Arabian and Red Seas, as well as the Bays of Bengal and the Persian Gulf. The Suez Canal connects the northern part of the Red Sea with the Mediterranean.
At the bottom of the Indian Ocean there are huge sections of the earth's crust - the African Plate, the Antarctic Plate and the Indo-Australian Plate. Shifts in the earth's crust cause underwater earthquakes, which cause giant waves called tsunamis. As a result of earthquakes, new mountain ranges appear on the ocean floor. In some places, seamounts protrude above the surface of the water, forming most of the islands scattered in the Indian Ocean. There are deep depressions between the mountain ranges. For example, the depth of the Sunda Trench is approximately 7450 meters. The waters of the Indian Ocean are home to a variety of wildlife, including corals, sharks, whales, turtles and jellyfish. Powerful currents are huge streams of water moving through the warm blue expanses of the Indian Ocean. The Western Australian Current carries cold Antarctic waters north to the tropics.
The equatorial current, located below the equator, circulates warm waters counterclock-wise. Northern currents depend on the monsoon winds that cause heavy rainfall, which change their direction depending on the time of year.
Indian Ocean - people and history
Sailors and traders plied the waters of the Indian Ocean many centuries ago. Ships of the ancient Egyptians, Phoenicians, Persians and Indians passed along the main trade routes. IN early middle ages Settlers from India and Sri Lanka moved to Southeast Asia. Since ancient times, wooden ships called dhows sailed the Arabian Sea, carrying exotic spices, African ivory and textiles.
In the 15th century, the great Chinese navigator Zhen Ho led a large expedition across the Indian Ocean to the shores of India, Sri Lanka, Persia, the Arabian Peninsula and Africa. In 1497, the Portuguese navigator Vasco da Gama became the first European whose ship sailed around the southern tip of Africa and reached the shores of India. English, French and Dutch traders followed, and the era of colonial conquest began. Over the centuries, new settlers, traders and pirates have landed on the islands in the Indian Ocean. Many species of island animals that lived nowhere else in the world became extinct. For example, the dodo, a goose-sized flightless pigeon native to Mauritius, was exterminated by the end of the 17th century. Giant turtles on Rodrigues Island have disappeared 19th century. Exploration of the Indian Ocean continued in the 19th and 20th centuries. Scientists have done great job, mapping the topography of the seabed. Currently, Earth satellites launched into orbit take pictures of the ocean, measure its depth and transmit information messages.
Atlantic Ocean
Atlantic Ocean is the second largest and covers an area of 82 million square meters. km. It is almost half the size of the Pacific Ocean, but its size is constantly increasing. From the island of Iceland to the south in the middle of the ocean a powerful underwater ridge stretches. Its peaks are the Azores and Ascension Island. The Mid-Atlantic Ridge, a large mountain range on the ocean floor, is becoming wider each year by about an inch. The deepest part of the Atlantic Ocean is a trench located north of the island of Puerto Rico. Its depth is 9218 meters. If 150 million years ago there was no Atlantic Ocean, then over the next 150 million years, scientists suggest, it will begin to occupy more than half of the globe. The Atlantic Ocean greatly influences the climate and weather in Europe.
The Atlantic Ocean began to form 150 million years ago, when shifts in the Earth's crust separated North and South America from Europe and Africa. This youngest of the oceans is named after the god Atlas, who was worshiped by the ancient Greeks.
Ancient peoples, such as the Phoenicians, began exploring the Atlantic Ocean around the 8th century BC. e. However, only in the 9th century AD. e. The Vikings managed to reach from the shores of Europe to Greenland and North America. The “golden age” of Atlantic exploration began with Christopher Columbus, an Italian navigator who served the Spanish monarchs. In 1492, his small squadron of three ships entered the Caribbean Gulf after a long storm. Columbus believed that he was sailing to the East Indies, but in fact he discovered the so-called New World - America. He was soon followed by other sailors from Portugal, Spain, France and England. The study of the Atlantic Ocean continues to this day. Currently, scientists use echolocation (sound waves) to map the topography of the seabed. Many countries fish in the Atlantic Ocean. People have fished these waters for thousands of years, but modern fishing by trawlers has led to a significant reduction in fishing schools. The seas surrounding the oceans are polluted with waste. The Atlantic Ocean continues to play a huge role in international trade. Many important trade sea routes pass through it.
Arctic Ocean
Arctic Ocean, which is located between Canada and Siberia, is the smallest and shallowest compared to the others. But it is also the most mysterious, since it is almost completely hidden under a huge layer of ice. The Arctic Ocean is divided into two basins by the Nansen Threshold. The Arctic basin is larger in area and contains the greatest ocean depth. It is equal to 5000 m and is located north of Franz Josef Land. In addition, here, off the Russian coast, there is an extensive continental shelf. For this reason, our Arctic seas, namely: Kara, Barents, Laptev, Chukotka, East Siberian, are shallow.
But I’ll remind you of something that exists recently . Look again what's going on
There are 4 oceans on our planet Earth
What are the oceans on our planet called?
1 – Pacific Ocean (the largest and deepest);
2 – Atlantic Ocean (second in volume and depth after the Pacific Ocean);
3 – Indian Ocean (third in volume and depth after the Pacific and Atlantic);
4 – Arctic Ocean (fourth and smallest in volume and depth among all oceans)
What is the ocean like? – This is a huge body of water located among the continents, which is constantly in interaction with the earth’s crust and the earth’s atmosphere. The area of the world's oceans, together with the seas included in it, is about 360 million square kilometers of the Earth's surface (71% of the total area of our planet).
IN different years The world's oceans were divided into 4 parts, while others divided it into 5 parts. For a long time Indeed, 4 oceans were distinguished: Indian, Pacific, Atlantic and Arctic (except for the Southern Ocean). The Southern Ocean is not part of the oceans due to its very arbitrary boundaries. However, at the beginning of the 21st century, the International Hydrographic Organization adopted a division into 5 parts, including territorial waters called the “Southern Ocean” in the list, but at the moment this document still does not have official legal force, and it is believed that the southern ocean is considered only conditionally by its name as the fifth on Earth. The Southern Ocean is also called the southern sea, which does not have its own clear independent boundaries, and it is believed that its waters are mixed, that is, the water currents of the Indian, Pacific and Atlantic oceans entering it.
Brief information about each ocean on the planet
- Pacific Ocean- is the largest in area (179.7 million km 2) and the deepest. Occupies about 50 percent of the entire surface of the Earth, the volume of water is 724 million km 3, maximum depth- 11022 meters (Mariana Trench, the deepest known on the planet).
- Atlantic Ocean- second in volume after Tikhoy. The name was given in honor of the famous titan Atlanta. The area is 91.6 million km 2, the volume of water is 29.5 million km 3, the maximum depth is 8742 meters (an oceanic trench, which is located on the border of the Caribbean Sea and the Atlantic Ocean).
- Indian Ocean covers approximately 20% of the Earth's surface. Its area is just over 76 million km2, its volume is 282.5 million km3, and its greatest depth is 7209 meters (the Sunda Trench extends for several thousand kilometers along the southern part of the Sunda island arc).
- Arctic Ocean considered the smallest among all. Thus, its area is “only” 14.75 million km 2, its volume is 18 million km 3, and its greatest depth is 5527 meters (located in the Greenland Sea).
The Ocean (ancient Greek Ὠκεανός, on behalf of the ancient Greek deity Ocean) is the largest body of water, part of the World Ocean, located among the continents, possessing a water circulation system and other specific features. The ocean is in continuous interaction with the atmosphere and the earth's crust. The surface area of the world's oceans, which includes oceans and seas, accounts for about 71 percent of the Earth's surface (about 361 million square kilometers). The bottom topography of the Earth's oceans is generally complex and varied.
The science that studies the oceans is called oceanology; The fauna and flora of the ocean is studied by a branch of biology called ocean biology.
Antique meaning
IN Ancient Rome the word Oceanus denoted the waters that washed known world from the west, that is, the open Atlantic Ocean. At the same time, the expressions Oceanus Germanicus (“German Ocean”) or Oceanus Septentrionalis (“North Ocean”) denoted the North Sea, and Oceanus Britannicus (“British Ocean”) denoted the English Channel.
Modern definition of oceans
The World Ocean is a global volume of sea water, the main part of the hydrosphere, constituting 94.1% of its total area, a continuous but not continuous water shell of the Earth, surrounding continents and islands and characterized by a common salt composition. Continents and large archipelagos divide the world's oceans into parts (oceans). Large regions of the oceans are known as seas, gulfs, straits, etc.
Some sources divided the World Ocean into four parts, others into five. From 1937 to 1953, five oceans were distinguished: the Pacific, Atlantic, Indian, Arctic and Southern (or Southern Arctic) ocean. The term “Southern Ocean” appeared many times back in the 18th century, when systematic exploration of the region began. In publications of the International Hydrographic Organization, the Southern Ocean was separated from the Atlantic, Indian and Pacific in 1937. There was a justification for this: in its southern part, the boundaries between the three oceans are very arbitrary, while at the same time, the waters adjacent to Antarctica have their own specifics, and are also united by the Antarctic Circumpolar Current. However, later they abandoned the distinction of a separate Southern Ocean. In 2000, the International Hydrographic Organization adopted a division into five oceans, but this decision has not yet been ratified. The current definition of oceans from 1953 does not include the Southern Ocean.
In the table below, in addition to the seas belonging to the oceans, the seas belonging to the Southern Ocean are also indicated.
|
Area, million km² |
Volume, million km³ |
Average depth, m |
Maximum depth, m |
||
| Atlantic |
8,742 (Puerto Rico Trough) |
Baltic, Northern, Mediterranean, Black, Sargasso, Caribbean, Adriatic, Azov, Balearic, Ionian, Irish, Marmara, Tyrrhenian, Aegean; Bay of Biscay, Gulf of Guinea, Gulf of Mexico, Hudson Bay : Weddell, Skosh, Lazarev |
|||
| Indian |
7,725 (Sunda Trench) |
Andaman, Arabian, Arafura, Red, Laccadive, Timor; Bay of Bengal, Persian Gulf Also related to the Southern Ocean: Rieser-Larsen, Davis, Cosmonauts, Commonwealth, Mawson |
|||
| Arctic |
5,527 (in Greenland Sea) |
Norwegian, Barents, White, Kara, Laptev, East Siberian, Chukotka, Greenland, Beaufort, Baffin, Lincoln | |||
| Quiet |
11 022 (Mariana Trench) |
Bering, Okhotsk, Japanese, East China, Yellow, South China, Javanese, Sulawesi, Sulu, Philippine, Coral, Fiji, Tasmanovo Also related to the Southern Ocean: D'Urville, Somov, Ross, Amundsen, Bellingshausen |
Brief characteristics of the oceans
The Pacific Ocean (or Great Ocean) is the largest ocean in terms of area and depth on Earth. Located between the continents of Eurasia and Australia in the west, North and South America in the east, Antarctica in the south. In the north, through the Bering Strait, it communicates with the waters of the Arctic Ocean, and in the south, with the Atlantic and Indian Oceans. Occupying 49.5% of the surface of the World Ocean and containing 53% of the volume of water in the World Ocean, the Pacific Ocean extends approximately 15.8 thousand km from north to south and 19.5 thousand km from east to west. The area with seas is 179.7 million km2, the average depth is 3984 m, the volume of water is 723.7 million km3 (without seas, respectively: 165.2 million km2, 4282 m and 707.6 million km3). The greatest depth of the Pacific Ocean (and the entire World Ocean) is 11,022 m in the Mariana Trench. The International Date Line runs across the Pacific Ocean approximately along the 180th meridian. The study and development of the Pacific Ocean began long before the written history of mankind. Junks, catamarans and simple rafts. The 1947 expedition on the balsa log raft Kon-Tiki, led by the Norwegian Thor Heyerdahl, proved the possibility of crossing the Pacific Ocean westward from central South America to the islands of Polynesia. Chinese junks made voyages along the ocean shores into the Indian Ocean (for example, the seven voyages of Zheng He in 1405-1433). Currently, the coast and islands of the Pacific Ocean are developed and populated extremely unevenly. The largest centers of industrial development are the US coast (from the Los Angeles area to the San Francisco area), the coast of Japan and South Korea. The role of the ocean in the economic life of Australia and New Zealand is significant.
The second largest ocean on Earth after the Pacific Ocean, the name comes from the name of the Titan Atlas (Atlanta) in Greek mythology or from the legendary island of Atlantis. It extends from subarctic latitudes all the way to Antarctica. The border with the Indian Ocean runs along the meridian of Cape Agulhas (20°E to the coast of Antarctica (Donning Maud Land). The border with the Pacific Ocean is drawn from Cape Horn along the meridian 68°04'W or the shortest distance from South America to the Antarctic Peninsula through the Drake Passage, from Oste Island to Cape Sterneck. The border with the Arctic Ocean runs along the eastern entrance of the Hudson Strait, then through the Davis Strait and along the coast of Greenland Island to Cape Brewster, through the Denmark Strait to Cape Reydinupyur on the island of Iceland, along its coast to Cape Gerpir, then to the Faroe Islands, further to the Shetland Islands and along 61° north latitude to the coast of the Scandinavian Peninsula.The area of the seas, bays and straits of the Atlantic Ocean is 14.69 million km2 (16% of the total ocean area), volume 29.47 million km³ (8.9%) Area 91.6 million km2, of which about a quarter is inland seas The area of coastal seas is small and does not exceed 1% of the total water area. The volume of water is 329.7 million km3, which is equal to 25% of the volume of the World Ocean. The average depth is 3736 m, the greatest is 8742 m (Puerto Rico Trench). The average annual salinity of ocean waters is about 35 ‰. The Atlantic Ocean is highly indented coastline with a pronounced division into regional waters: seas and bays.
The Indian Ocean is the third largest ocean on Earth, covering about 20% of its water surface. The Indian Ocean is mainly located south of the Tropic of Cancer between Eurasia to the north, Africa to the west, Australia to the east and Antarctica to the south.
Its area is 76.17 million km2, volume - 282.65 million km3. In the north it washes Asia, in the west - Arabian Peninsula and Africa, in the east - Indochina, the Sunda Islands and Australia; in the south it borders the Southern Ocean.
The border with the Atlantic Ocean runs along the 20° meridian of eastern longitude; from Quiet - along the 147° meridian of eastern longitude.
The northernmost point of the Indian Ocean is located at approximately 30°N latitude in Persian Gulf. The Indian Ocean is approximately 10,000 km wide between the southern points of Australia and Africa.
The Arctic Ocean (English Arctic Ocean, Danish Ishavet, Norse and Nynorsk Nordishavet) is the smallest ocean on Earth by area, located between Eurasia and North America.
The area is 14.75 million km2, that is, slightly more than 4% of the entire area of the World Ocean, the average depth is 1,225 m, the volume of water is 18.07 million km3.
The Arctic Ocean is the shallowest of all oceans, with an average depth of 1,225 m (the greatest depth is 5,527 m in the Greenland Sea).
Formation of the oceans
Today, there is a version in scientific circles that the ocean appeared 3.5 billion years ago as a consequence of degassing of magma and subsequent condensation of atmospheric vapor. Most modern ocean basins arose in the last 250 million years as a result of the breakup of an ancient supercontinent and the divergence of lithospheric plates to the sides (the so-called spreading). The exception is the Pacific Ocean, which is a shrinking remnant of the ancient Panthalassa Ocean.
Bathymetric position
Based on the bathymetric position and nature of the relief on the ocean floor, the following several stages are distinguished:
- Shelf - depth up to 200-500 m
- Continental slope - depth up to 3500 m
- Ocean bed - depth up to 6000 m
- Deep sea trenches - depth below 6000 m
Ocean and atmosphere
The ocean and atmosphere are fluid media. The properties of these environments determine the habitat of organisms. Flows in the atmosphere affect the general circulation of water in the oceans, and the properties of ocean waters depend on the composition and temperature of the air. In turn, the ocean determines the basic 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 influenced by winds, the rotation of the Earth, and land barriers.
Ocean and climate
The ocean warms up more slowly in summer and cools down more slowly in winter. This makes it possible to smooth out temperature fluctuations on land adjacent to the ocean.
The atmosphere receives from the ocean a significant part of the heat supplied to it and almost all the water vapor. The steam rises, condenses, forming clouds, which are carried by the winds and fall as rain or snow on land. Only surface waters of the ocean participate in heat and moisture exchange. Internal ones (about 95%) do not participate in the exchange.
Chemical composition of water
The ocean contains an inexhaustible source of chemical elements, which are contained in its water, as well as in deposits located on the bottom. There is a constant renewal of mineral deposits, through the fall or introduction to the bottom of various sediments and solutions from the earth's crust.
The average salinity of sea water is 35 ‰. The salty taste of water is given by the 3.5% dissolved minerals it contains - these are mainly sodium and chlorine compounds.
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 parts of the ocean.
Flora and fauna
The Pacific Ocean accounts for more than 50% of the total biomass of the World Ocean. Life in the ocean is abundant and diverse, especially in the tropical and subtropical zones between the coasts of Asia and Australia, where vast areas are occupied by coral reefs and mangroves. Phytoplankton in the Pacific Ocean consists primarily of microscopic single-celled algae, numbering about 1,300 species. In the tropics, fucus algae, large green algae, and especially the famous red algae are especially common, which, along with coral polyps, are reef-forming organisms. 
The flora of the Atlantic is distinguished by species diversity. The water column is dominated by phytoplankton, consisting of dinoflagellates and diatoms. At the height of their seasonal bloom, the sea off the coast of Florida turns bright red, and a liter of seawater contains tens of millions of single-celled plants. The bottom flora is represented by brown (fucus, kelp), green, red algae and some vascular plants. In the estuaries of rivers, sea zoster, or eelgrass, grows, and in the tropics green (caulerpa, valonia) and brown (sargassum) algae predominate. The southern part of the ocean is characterized by brown algae (Fucus, Lesonia, Electus). Animal world It is distinguished by a large - about a hundred - number of bipolar species that live only in cold and temperate zones and are absent in the tropics. First of all, these are large sea animals (whales, seals, fur seals) and ocean birds. They live in tropical latitudes sea urchins, coral polyps, sharks, parrotfish and surgeonfish. Dolphins are often found in Atlantic waters. The cheerful intellectuals of the animal kingdom willingly accompany ships large and small - sometimes, unfortunately, falling under the merciless blades of the propellers. The indigenous inhabitants of the Atlantic are the African manatee and the largest mammal on the planet - the blue whale.
The flora and fauna of the Indian Ocean are incredibly diverse. The tropical region is distinguished by the richness of plankton. The unicellular algae Trichodesmium (a type of Cyanobacterium) is especially abundant, due to which the surface layer of water becomes very cloudy and changes its color. The plankton of the Indian Ocean is distinguished by a large number of organisms that glow at night: peridines, some types of jellyfish, ctenophores, and tunicates. Brightly colored siphonophores are abundant, including poisonous phasalia. In temperate and arctic waters, the main representatives of plankton are copepods, eufuazides and diatoms. The most numerous fish of the Indian Ocean are coryphens, tunas, nototheniids and various sharks. Among reptiles there are several species of giant sea turtles, sea snakes, and among mammals there are cetaceans (toothless and blue whales, sperm whales, dolphins), seals, and elephant seals. Most cetaceans live in temperate and subpolar regions, where, due to intense mixing of waters, favorable conditions for the development of planktonic organisms. The flora of the Indian Ocean is represented by brown (sargassum, turbinaria) and green algae (caulerna). The calcareous algae lithothamnia and halimeda also develop luxuriantly, which participate together with corals in the construction of reef structures. Typical for the coastal zone of the Indian Ocean is the phytocenosis formed by mangroves. For temperate and Antarctic waters, the most characteristic are red and brown algae, mainly from the fucus and kelp groups, porphyry, and gelidium. Giant macrocystis are found in the polar regions of the southern hemisphere.
The reason for the poverty of the organic world of the Arctic Ocean is harsh climatic conditions. The only exceptions are the North European Basin, Barents and White Sea with their extremely rich flora and fauna. The ocean flora is represented mainly by kelp, fucus, ahnfeltia, and in the White Sea - also zostera. The seabed fauna of the eastern Arctic, especially the central part of the Arctic basin, is extremely poor. There are more than 150 species of fish in the Arctic Ocean, including a large number of commercial fish (herring, cod, salmon, scorpionfish, flounder and others). Seabirds in the Arctic lead a predominantly colonial lifestyle and live on the shores. Mammals are represented by seals, walruses, beluga whales, whales (mainly minke and bowhead whales), and narwhals. Lemmings are found on the islands, and arctic foxes and reindeer cross the ice bridges. The polar bear, whose life is mainly associated with drifting ice, pack ice or coastal fast ice, should also be considered a representative of the ocean fauna. Most animals and birds all year round (and some only in winter) are white or very light in color.
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The favorite question of all geography teachers is: “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 occur in it. This article will tell you about this and many other interesting facts about the hydrosphere.
After long observations, all the scientists of the world came to the conclusion that to the question of how many oceans there are on Earth, the answer will be unequivocal - four. If you look at the history of hydrosphere research, you will see that it was the first to be discovered. It is rightfully considered the warmest on Earth, because in the summer near the coasts its waters can warm up to a record temperature of 35˚C.
After a trip trying to find a way to India - the most attractive country for Europeans at that time - humanity learned about a new large body of water. In honor of the Greek titan Atlas, whom mythology endowed with a tough temperament 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 more oceans are there on Earth? Among the previously unnamed, two remained: Quiet and Northern Arctic. in fact, it got its name by mistake, since during his trip around the world Magellan was very lucky with the weather. As a result, the researcher thought that the ocean had a gentle disposition, but this is far from the case. Tsunamis often occur off the western coast of North America.
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 flora and fauna can withstand the harsh living conditions in it.
There was a period when some scientists, when asked: “How many oceans are there on Earth?” - they answered: “Five.” They identified another body of water that washes the shores of Antarctica. It was given the name Southern, but its boundaries are so unclear that over time the compilers geographical maps no longer designate this ocean.
This is common knowledge about how many oceans there are on Earth. Many space researchers believe that the hydrosphere could exist on other planets solar system. For example, scientists around the world are asking the question: “How many oceans once existed on the planet Mars?” They have not yet found the answer, but if the hydrosphere was still there, then, most likely, living organisms could also live on the neighboring planet millions of years ago.
The world's oceans form a continuous chain on our planet, components which are all of the above. He is the source of life, therefore humanity must protect such an important resource as pure water. Thanks to the competent distribution of these reserves, people guarantee themselves normal existence, as well as reducing the likelihood of various natural disasters.
