1. Ocean exploration​

   ​

   The ocean is very beautiful and tempting, it is home to many different species of fish and not only, the ocean also helps our Earth in the production of oxygen and plays an important role in its climate. But people, relatively recently, began to study it in detail, and were surprised by the results.
   Oceanology is the science that deals with the study of the ocean. It also helps us to significantly deepen our knowledge about the natural forces of the Earth, including mountain building, earthquakes, volcanic eruptions.
   The first explorers believed that the ocean was an obstacle on the way to distant lands. They had little interest in what was in the depths of the ocean, despite the fact that the world ocean occupies more than 70% of the Earth's surface.
   It is for this reason that even 150 years ago the idea that the ocean floor was a huge plain devoid of any relief elements dominated.
   In the 20th century, scientific exploration of the ocean began. In 1872 - 1876. The first serious voyage for scientific purposes took place on board the British vessel Challenger, which had special equipment, and its crew consisted of scientists and sailors.
   In many ways, the results of this oceanographic expedition have enriched human knowledge about the oceans and their flora and fauna.

   Deep in the ocean​

   ​

   On the Challenger, for measuring the ocean depths, there were special lotlines, which consisted of lead balls weighing 91 kg, these balls were fixed on a hemp rope.
   It could take several hours to sink such a lotlin to the bottom of a deep-sea trench, and on top of that, this method quite often did not provide the necessary accuracy in measuring great depths.
   Echo sounders appeared in the 1920s. This made it possible to determine the ocean depth in just a few seconds from the time elapsed between the sending of a sound pulse and the reception of a signal reflected by the bottom.
   The vessels, which were equipped with echo sounders, measured the depth along the way and received a profile of the ocean floor. The newest system of deep-sea soundings "Gloria" has appeared on ships since 1987. This system made it possible to scan the ocean floor in strips 60 m wide.
   Previously used to measure ocean depths, weighted lotlines were often fitted with small soil tubes to take soil samples from the ocean floor. Modern samplers are large in weight and size, and they can dive to a depth of 50 m in soft bottom sediments.

   Biggest discoveries​

   Intensive ocean exploration began after World War II. The discoveries of 1950-1960 related to the rocks of the oceanic crust revolutionized the earth sciences.
   These discoveries proved the fact that the oceans are relatively young, and also confirmed that the movement of the lithospheric plates that gave rise to them continues today, slowly changing the earth's appearance.
   The movement of lithospheric plates causes volcanic eruptions and earthquakes, and also leads to the formation of mountains. The study of the oceanic crust continues.
   The ship "Glomar Challenger" in the period 1968 - 1983 was on a circumnavigation. It supplied geologists with valuable information, drilling holes in the ocean floor.
   The Resolution vessel of the United Oceanographic Deep Drilling Society performed this task in the 1980s. This vessel was capable of underwater drilling at depths of up to 8,300 m.
   Seismic surveys also provide data on ocean floor rocks: shock waves sent from the surface of the water are reflected from different rock layers in different ways.
   As a result, scientists receive very valuable information about possible oil deposits and about the structure of rocks.
   Other automatic instruments are used to measure current speed and temperature at different depths, as well as to take water samples.
   Artificial satellites also play an important role: they monitor ocean currents and temperatures, which affect the Earth's climate.
   It is thanks to this that we receive very important information about climate change and global warming.
   Scuba divers in coastal waters can easily dive to depths of up to 100 m. But at depths that are greater, they dive, gradually increasing and relieving pressure.
   This method of immersion is successfully used to detect sunken ships and in offshore oil fields.
   This method gives you much more diving power than diving bells or heavy diving suits.

   ​

   Submersibles​

   The ideal vehicle for exploring the oceans is submarines. But most of them belong to the military. For this reason, scientists have created their own devices.
   The first such devices appeared in 1930-1940. American lieutenant Donald Walsh and Swiss scientist Jacques Piccard, in 1960, set a world record for diving in the deepest region of the world - in the Mariana Trench of the Pacific Ocean (Challenger Trench).
   On the Trieste bathyscaphe, they descended to a depth of 10,917 m, and found unusual fish in the depths of the ocean.
   But perhaps the most impressive in the more recent past were the events associated with the tiny US submersible "Alvin", with the help of which in 1985 - 1986. The wreckage of the Titanic was studied at a depth of about 4,000 m.

   ​

   We conclude: the vast world ocean has been studied quite a bit and we have to study it more and more in depth. And who knows what discoveries await us in the future... This is a big mystery that is gradually being revealed to mankind thanks to the exploration of the world's oceans.

   What do you know about the oceans?​

2. 
   A group of American scientists led by Robert Sarmast claims that they have found convincing evidence of the true location of the legendary Atlantis near Cyprus. The mainland described by Plato, the researchers prove, was between Cyprus and Syria

3. Now the amount of organic plankton in the oceans is declining, and this is the biggest problem!!! because it is the initial link in the food chain of all life on earth. Man naturally influences its reduction, since technogenic factors (radiation, pollution of the coastal zone of the oceans, emissions of oil, fuel and all other rubbish) depend on it

4. sea ​​currents
   sea ​​currents- constant or periodic flows in the thickness of the world's oceans and seas. There are constant, periodic and irregular currents; surface and underwater, warm and cold currents. Depending on the cause of the current, wind and density currents are distinguished. The flow rate is measured in Sverdrups.
   Current classification
   There are three groups of currents:
   gradient flows caused by horizontal hydrostatic pressure gradients that occur when isobaric surfaces are tilted relative to isopotential (level) surfaces.
   1) Density, caused by a horizontal density gradient
   2) Compensatory, caused by the tilt of the sea level under the influence of the wind
   3) Barogradient, caused by uneven atmospheric pressure over the sea surface
   4) Seiche, resulting from seiche fluctuations in sea level
   5) Sink or waste, resulting from the occurrence of excess water in any area of ​​the sea (as a result of the influx of continental waters, precipitation, ice melting)
   wind driven currents
   1) Drift, caused only by the entraining action of the wind
   2) Wind, caused by both the entraining action of the wind, and the slope of the sea level and the change in water density caused by the wind
   tidal currents caused by tides.
   1) Rip current
   Gulfstream
   
   gulf stream- - a warm sea current in the Atlantic Ocean. The continuation of the Gulf Stream is the North Atlantic Current. Thanks to the Gulf Stream, the countries of Europe adjacent to the Atlantic Ocean have a milder climate than other regions at the same geographical latitude: masses of warm water heat the air above them, which is transferred to Europe by westerly winds. Deviations of air temperature from average latitude values ​​in January reach 15-20 °C in Norway, and more than 11 °C in Murmansk.
   The flow of water by the Gulf Stream is 50 million cubic meters of water every second, which is 20 times more than the flow of all the rivers of the world combined. The thermal power is approximately 1.4×10(15) watts.
   Emergence and course
   Several factors play a role in the emergence and course of the Gulf Stream. These include atmospheric circulation and the increasing northward Coriolis force. The predecessor of the Gulf Stream, the Yucatan Current, flows from the Caribbean Sea into the Gulf of Mexico through a narrow strait between Cuba and Yucatan. There, the water either leaves along the gulf's circular current or forms the Florida current and follows through an even narrower strait between Cuba and Florida and exits into the Atlantic Ocean.
   Having managed to gain a lot of heat in the Gulf of Mexico, the Florida Current joins the Antilles Current near the Bahamas and turns into the Gulf Stream, which flows in a narrow strip along the coast of North America. At the level of North Carolina, the Gulf Stream leaves the coastal zone and turns into the open ocean. About 1500 km further, it collides with the cold Labrador Current, which deflects it further east towards Europe. The Coriolis force also acts as the engine of the movement to the east. On the way to Europe, the Gulf Stream loses a lot of energy due to evaporation, cooling, and numerous side branches that reduce the main stream, but it still delivers enough heat to Europe to create a mild climate unusual for its latitudes. The continuation of the Gulf Stream to the northeast of the Great Newfoundland Bank is the North Atlantic Current. The average water flow in the Strait of Florida is 25 million m³/s.
   The Gulf Stream often forms rings - whirlwinds in the ocean. Separated from the Gulf Stream as a result of meandering, they have a diameter of about 200 km and move in the ocean at a speed of 3-5 cm/s.
   Whirlwinds in the ocean- circular movements of ocean water, similar to the circular movements of air in the vortices of the atmosphere
   
   Possibility of the impact of the accident on the Deepwater Horizon platform on the Gulf Stream
   In connection with the emergency release of oil on the Deepwater Horizon platform in the Gulf of Mexico in April 2010, there were reports of a break in the continuous flow: as a result of the outflow of oil from a damaged well, the flow in the bay may have closed into a ring and heats itself, and in the main The Gulf Stream in the Atlantic receives less warm water than before. At the moment, there are no reasonable forecasts of the impact on the main
   Gulf Stream warming Europe.
   

   paphos said:

   They say that space is even better explored than the ocean...

   Click to reveal...

   And this is possible.
   Which oceans are the largest?
   We usually think like this: The earth is made up of continents separated by seas and oceans. In fact, our Earth is an ocean from which islands and continents rise. 7/10 of the earth's surface is covered by five large oceans, which are interconnected.
   The widest and largest ocean - Quiet, many islands “crawl out” of it. The Atlantic Ocean separates America from Europe and Africa, it is the narrowest. The Indian Ocean surrounds the Indian subcontinent. The Arctic Ocean (Arctic) surrounds the North Pole. Antarctic - Southern.
   Pacific Ocean:
   
   Square
   surfaces
   water, million km² = 178,68
   Volume,
   million km³ = 710,36
   Average depth = 3976
   Greatest ocean depth= Mariana Trench (11022)
   Research History
   The Spanish conquistador Vasco Nunez de Balboa in 1510 founded the settlement of Santa Maria la Antigua del Darién (es: Santa María la Antigua del Darién) on the western shore of the Gulf of Darién. Soon news reached him of a rich country and a large sea located in the south. Balboa with a detachment moved out of his city (September 1, 1513), and four weeks later, from one of the peaks of the mountain range, “in silence”, he saw the boundless water surface of the Pacific Ocean spreading to the west. He went to the ocean and christened it the South Sea (Spanish: Mar del Sur).
   In the autumn of 1520, Magellan went around South America, breaking the strait, after which he saw new expanses of water. During the further transition from Tierra del Fuego to the Philippine Islands, for more than three months the expedition did not encounter a single storm, which is obviously why Magellan called the Pacific Ocean (lat. Mare Pacificum). The first detailed map of the Pacific Ocean was published by Ortelius in 1589.
   The seas: Weddell, Scotch, Bellingshausen, Ross, Amundsen, Davis, Lazarev, Riiser-Larsen, Cosmonauts, Commonwealth, Mawson, D'Urville, Somov are now included in the Southern Ocean.
   By the number (about 10 thousand) and the total area of ​​the islands (about 3.6 million km²), the Pacific Ocean ranks first among the oceans. In the northern part - the Aleutian; in the western - Kuril, Sakhalin, Japanese, Philippine, Greater and Lesser Sunda, New Guinea, New Zealand, Tasmania; in the central and southern - numerous small islands. The islands of the central and western oceans make up the geographical region of Oceania.
   The Pacific Ocean at different times had several names:
   The Southern Ocean or the South Sea (Mar del Sur) - this is how the Spanish conquistador Balboa called it, the first European to see it in 1513. Today, the Southern Ocean is called the waters around Antarctica.
   Great Ocean - named by the French geographer Buachem in 1753. The most correct, but not accustomed name.
   Eastern Ocean - sometimes called in Russia.
   currents
   The main surface currents: in the northern part of the Pacific Ocean - warm Kuroshio, North Pacific and Alaska and cold California and Kuril; in the southern part - warm South Trade Winds, Japanese and East Australian and cold West Winds and Peruvian.
   Physical location
   Covering over a third of the earth's surface Pacific Ocean is the largest ocean in the world. This ocean stretches from Eurasia to America and from the Arctic Ocean to the current of the West Winds in the Southern Hemisphere.
   Its waters are located mostly in the southern latitudes, less - in the northern ones. With its eastern edge, the ocean washes the western coasts of North and South America, and with its western edge, it washes the eastern coasts of Australia and Eurasia. Almost all of its associated seas are located on the northern and western sides, such as the Bering, Okhotsk, Japanese, East China, Yellow, South China, Australo-Asian, Coral, Tasmanovo; Near Antarctica are the Amundsen, Bellingshausen and Ross Seas.
   Flora and fauna
   The Pacific Ocean is distinguished by the richest fauna, in the tropical and subtropical zones between the coasts of Asia and Australia (here vast territories are occupied by coral reefs and mangroves) in common with the Indian Ocean. Of the endemics, nautilus mollusks, poisonous sea snakes and the only species of marine insects, the water strider of the genus Halobates, should be mentioned. Of the 100 thousand species of animals, 3 thousand are represented by fish, of which about 75% are endemic. The waters off the Fiji Islands are inhabited by numerous populations of sea anemones. Fish of the pomacentric family feel great among the burning tentacles of these animals. Of the mammals, among others, walruses, seals and sea otters live here. The sea lion inhabits the coasts of the California Peninsula, the Galapagos Islands and Japan.
   
   

5. Origin of the oceans
   
   The origin of the oceans has been the subject of hundreds of years of controversy.
   It is believed that the ocean was hot in the Archaean. Due to the high partial pressure of carbon dioxide in the atmosphere, which reached 5 bar, its waters were saturated with H2CO(3) carbonic acid and were acidic (рН ≈ 3−5). A large number of different metals were dissolved in this water, especially iron in the form of FeCl(2) chloride.
   The activity of photosynthetic bacteria led to the appearance of oxygen in the atmosphere. It was absorbed by the ocean and spent on the oxidation of iron dissolved in water.
   There is a hypothesis that starting from the Silurian period of the Paleozoic and up to the Mesozoic, the supercontinent Pangea was surrounded by the ancient Panthalassa ocean, which covered about half of the globe.
   How did the oceans form?
   
   In the history of the Earth, there are still many unsolved mysteries and mysteries. One of them is the question of how the oceans formed.
   In fact, we don't even know exactly when it happened. It seems, however, beyond doubt that they did not exist in the earliest period of the Earth's development. It is possible that in the beginning the ocean was a huge cloud of steam that turned into water as the surface of the Earth cooled. According to scientists, based on information about the amount of mineral salts in the ocean, this happened from 500,000,000 to 1,000,000,000 years ago.
   Modern theories claim that at one time almost the entire surface of the planet was sea. Some areas of the Earth several times found themselves under the waves of the seas. However, it is not known whether this section of the ocean floor was land and vice versa.
   There is ample evidence that, at one time or another, various parts of the land were covered by shallow seas. Most of the limestone, sandstone, and shale found on solid land are sedimentary rocks—deposits of mineral salts on the seafloor over millions of years. The most common chalk is a compressed cluster of shells of tiny creatures that once lived in the seas.
   Today, the waves of the world's oceans cover almost three-quarters of the Earth's surface. Although there are still many regions in which man has not explored the ocean floor, we know approximately what its appearance is. It is not as diverse as the surface of the continents, however, it also has mountain ranges, plains and deep depressions.
   Is there life in boiling water?
   
   bacteria, but nature, as always, refuted this belief. At the bottom of the Pacific Ocean, super-hot springs with water temperatures from 250 to 400 degrees Celsius were discovered, and it turned out that living organisms feel great in this boiling water: bacteria, giant worms, various mollusks, and even some types of crabs.
   This discovery seemed incredible. Suffice it to recall that most plants and animals die at body temperatures above 40 degrees, and most bacteria - at a temperature 70 degrees. Only very few bacteria can survive at 85 degrees, and the bacteria that live in sulfur springs have always been considered the most resistant. They could exist at temperatures up to 105 degrees. But that was already the limit.
   It turns out that there is no limit in nature, but there is something unknown or not yet discovered, as happened with heat-resistant living organisms at the bottom of the ocean. Moreover, when the boiling water, raised for analysis from the bottom of the ocean, cooled down a little (to about +80 degrees) the bacteria living in it stopped multiplying, apparently due to the cold.
   The French scientist L.Thoma named creatures living in boiling water one of the wonders of the world in modern biology. Thus, another mystery of nature has been discovered, which forces us to reconsider our previous ideas about the conditions under which and how life can develop.

6. How is the ocean studied?
   
   As in any other scientific discipline, theoretical and experimental studies stand out in oceanology. They are closely related. Observational data obtained in experiments require theoretical understanding in order to form a complete picture of the structure of the object of interest to you - the ocean. Theoretical models, in turn, suggest how to organize follow-up observations in order to gain as much new knowledge as possible.
   Until recently, the main means of experimental study of the ocean, with the exception of incidental observations of inquisitive navigators, were sea expeditions on research ships. Such ships must have special equipment - devices for measuring water temperature, its chemical composition, current speed, devices for sampling soil from the seabed and for catching the inhabitants of the sea depths. The first oceanographic instruments were lowered from the ship on a metal cable using a conventional winch.
   Measuring the properties of water at great depths requires special ingenuity. Indeed, how to take readings from an instrument located at a depth of several kilometers? Bring it to the surface? But during the ascent, the sensor of the device passes through a variety of layers of water, and its readings change many times. To fix, for example, the temperature values ​​at the desired depth, a special, so-called tilting thermometer is used. After turning “upside down”, such a thermometer no longer changes its readings and records the water temperature at the depth at which the capsizing occurred. The signal for overturning is the fall of the messenger weight, sliding down the carrying cable. In the same way, when turned over, the necks of the vessels for sampling water for chemical analysis are also closed. Such vessels are called bottles.
   In recent years, such relatively simple instruments, which have served oceanographers for a long time, have increasingly been replaced by electronic devices that are lowered into the water column on a conductive cable. Through such a cable, the device communicates with the on-board computer, which stores and processes data coming from the depths.
   But even such devices, which are more accurate and more convenient to use than their predecessors, are not enough to get a complete picture of the state of the ocean. The fact is that the dimensions of the World Ocean are so large (its area is 71% of the area of ​​the entire Earth, that is, 360 million square meters. km) that it will take many decades for the fastest ship to visit all areas of the ocean. During this time, the state of its waters changes significantly, just as the weather changes in the atmosphere. As a result, only a fragmentary picture is obtained, distorted due to the length of observations over time.
   To the aid of oceanologists come artificial earth satellites making several revolutions within one day, or “immobilely” hovering over any point on the earth's equator at a very high altitude, from where you can cover almost half of the earth's surface with your eyes.
   Measuring the characteristics of the ocean from a satellite height is not so easy, but possible. Even changes in the color of the water, noticed by the astronauts, can tell a lot about the movement of the waters. Even more precisely, the movement of waters can be traced by the movements of drifting buoys observed from satellites. But most of the information is extracted from the registration of electromagnetic radiation emitted by the surface of the ocean. By analyzing this radiation, captured by satellite instruments, it is possible to determine the temperature of the ocean surface, the speed of the surface wind, the height of wind waves and other indicators that are of interest to oceanologists.
   

7. Atlantic Ocean
   
   Square
   91.66 million km²
   Volume
   329.66 million km³
   Greatest depth
   8742 m
   Average depth
   3597 m
   Atlantic Ocean- the second largest ocean after the Pacific Ocean.
   The area is 91.6 million km², of which about a quarter falls on the 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 the ocean waters is about 35 ‰. The Atlantic Ocean has a strongly indented coastline with a pronounced division into regional water areas: seas and bays.
   The name comes from the name of the titan Atlas (Atlanta) in Greek mythology or from the legendary island of Atlantis.
   Research History
   History of the discovery of the Atlantic
   The Greek historian was the first among the philosophers of antiquity to use the word "Atlantic" in his writings. Herodotus, who wrote that "the sea on which the Hellenes swim, and that which is beyond the Pillars of Hercules, is called the Atlantic." The term "Atlantic Ocean" is found in the writings of Eratosthenes of Cyrene (III century BC) and Pliny the Elder (I century AD), but scientists are still not sure which water area it designated in antiquity. Perhaps this was the name of the water area between the Strait of Gibraltar and the Canary Islands.
   Long before the era of great geographical discoveries, the vastness of the Atlantic plowed numerous ships of the Vikings, Carthaginians, Phoenicians, Normans and Basques. For example, the Basque tribe settled on the Iberian Peninsula in ancient times, even before the appearance of the Indo-European peoples on the continent. Feeding on fishing, but not having access to the quiet bays of the warm Mediterranean Sea, the Basques, willy-nilly, thoroughly studied the stormy Bay of Biscay, which has long been infamous. It cannot be ruled out that a few centuries before Columbus they reached the “land of Dried Fish” (Newfoundland Island) on the other side of the Atlantic: the waters there are still famous for their richest fish stocks. In X-XI Art. the Normans wrote a new page in the study of the northern part of the Atlantic Ocean. According to most researchers of pre-Columbian discoveries, the Scandinavian Vikings were the first to cross the ocean more than once, reaching the shores of the American continent (they called it Vinland) and discovering Greenland and Labrador. If they had succeeded in colonizing the New World, then perhaps today Canada would be an overseas province of Sweden or Norway.
   Several centuries later, the expeditions of Christopher Columbus mapped many islands of the Caribbean and a huge mainland, later called America. The British were not slow to equip several research expeditions to the northeastern shores of the New World, which collected very valuable information, and in 1529 Spanish cartographers compiled a map of the northern part of the Atlantic, washing the western shores of Europe and Africa, and marked dangerous shoals and reefs on it.
   At the end of the 15th century, the rivalry between Spain and Portugal for dominance in the Atlantic escalated so much that the Vatican was forced to intervene in the conflict. In 1494, an agreement was signed, which along the 48-49 ° west longitude established the so-called. papal meridian. All lands to the west of it were given to Spain, and to the east - to Portugal. In the 16th century, as the colonial wealth was being developed, the waves of the Atlantic began to regularly surf the ships carrying gold, silver, precious stones, pepper, cocoa and sugar to Europe. Weapons, fabrics, alcohol, food and slaves for cotton and sugar cane plantations were delivered to America in the same way. It is not surprising that in the XVI-XVII centuries. piracy and privateering flourished in these parts, and many famous pirates, such as John Hawkins, Francis Drake and Henry Morgan, entered their names into history.
   On the maps of European navigators compiled in the 17th century, the name "Ethiopian Sea" appears, and the toponym "Atlantic" returned only at the end of the 18th century.
   The first attempts to study the seabed were made in 1779 near the coast of Denmark, and the first Russian round-the-world expedition under the command of naval officer Ivan Kruzenshtern laid the foundation for serious scientific research in 1803-06. Participants of subsequent trips measured the temperature and specific gravity of water at different depths, took samples of water transparency and established the presence of undercurrents.
   Not wanting to be left behind, the British in the same years undertook a number of successful scientific expeditions. In 1817-18. John Ross sailed on the Isabella, and in 1839-43. his nephew James sailed to Antarctica three times on the Erebus and Terror. A turning point in the history of underwater research was the appearance in 1845 of a new bottom probe designed by John Brooke. During 1868-76. The Royal Geographical Society of Great Britain organized a number of oceanographic expeditions led by Lord Charles Thomson, a professor at the University of Edinburgh. In the second half of the XIX and early XX centuries. systematic studies were carried out in the Gulf of Mexico and the Caribbean Sea. Equally valuable scientific results were brought by the expedition of Erich von Drygalski on the ship "Gauss" (1901-03), whose members carried out careful measurements in the northeastern and southeastern parts of the Atlantic. In 1899, at the international oceanographic conference in Stockholm, it was decided to start creating a bathymetric map of the ocean on a scale of 1:10,000,000 (the first maps of this type appeared in the middle of the 19th century). In the first half of the 20th century, a number of scientific expeditions were undertaken by Germany, Britain, the USA and Russia, as a result of which scientists received a detailed idea of ​​the Mid-Atlantic Ridge. In 1968, the American ship "Glomar Challenger" conducted research on underwater cracks in the earth's crust, and in 1971-80. The program of the International Decade of Oceanographic Research was successfully implemented.
   
   general description
   Seas - Baltic, Northern, Mediterranean, Black, Sargasso, Caribbean, Adriatic, Azov, Balearic, Ionian, Irish, Marble, Tyrrhenian, Aegean. Large bays - Biscay, Guinean, Mexican, Hudson.
   Main islands: British, Iceland, Newfoundland, Greater and Lesser Antilles, Canary Islands, Cape Verde, Falkland (Malvinas).
   The meridional Mid-Atlantic Ridge divides the Atlantic Ocean into eastern and western parts.
   The main surface currents: warm North Trade Wind, Gulf Stream and North Atlantic, cold Labrador and Canary in the North Atlantic Ocean; warm South Trade Winds and Brazil, cold West Winds and Benguela in the South Atlantic Ocean.
   The highest tide is 18 m (Bay of Fundy). The surface water temperature near the equator is up to 28 °C. It freezes at high latitudes. Salinity 34-37.3%.
   Fishing: (herring, cod, sea bass, hake, tuna, etc.) - 2/5 of the world catch. Oil production on the shelves of the Gulf of Mexico, the Caribbean Sea, the North Sea.
   
   Map of the depths of the Atlantic Ocean.
   Geological structure
   The Atlantic Ocean was formed in the Mesozoic as a result of the split of the ancient supercontinent Pangea and the drift of the continents. The split of Pangea went from north to south and began in the Triassic, and ended in the Cretaceous. Then the Atlantic Ocean expanded due to the movement of the North American and South American plates in the Zainozoic, the Tethys Ocean closed, and the African plate shifted to the north. In the North Atlantic Ocean, the spreading zone was located between North America and Greenland, where the Baffin Sea is now located. Spreading then moved east, between Greenland and the Scandinavian Peninsula.
   The bottom of the Atlantic Ocean in its northern part belongs to the North American and Eurasian plates, the central and southern part is underlain by the South American, African, Caribbean plates and the Scotia plate in the south.
   Flora, fauna and mineral resources
   The flora of the Atlantic is not 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 sea water 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 mouths of the rivers, sea zoster, or eelgrass, grows, and in the tropics, green (caulerpa, wallonia) and brown (sargasso) algae predominate. The southern part of the ocean is characterized by brown algae (fucus, forestia, 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. Sea urchins, coral polyps, sharks, parrot fish and surgeon fish live in tropical latitudes. Dolphins are often found in the waters of the Atlantic. Cheerful intellectuals of the animal world willingly accompany large and small vessels - sometimes, unfortunately, falling under the ruthless blades of propellers. The native inhabitants of the Atlantic are the African manatee and the largest mammal on the planet, the blue whale.
   
   
   

8. Why is the Atlantic Ocean the saltiest water?
   
   The Atlantic Ocean covers an area of ​​92 million km2. It is considered the most saline of all the oceans, despite the fact that it collects fresh water from the largest part of the land. The salt content in the waters of the Atlantic is on average 35.4%, which is more than the salinity of the Pacific, Indian and Arctic oceans. True, it is worth noting that some scientists believe that the Indian Ocean is the most saline.
   The fact is that, on average, salinity is greater near the Atlantic Ocean, but if we take individual zones of the Indian Ocean, then there will undoubtedly be places where salinity reaches more than 35.4%. This is especially noticeable in the northwestern part of the Indian Ocean, where the hot breath of the Sahara is added to the high temperature of the water. The record holder for salinity is the Red Sea (up to 42 and the Persian Gulf. Unlike the northern waters, in the south, in the Antarctic region, the salinity of the Indian Ocean is significantly reduced.
   In the Atlantic Ocean, salinity is more evenly distributed, which in general affects the greater salinity of the ocean as a whole.
   Of course, the distribution of salinity is not always zonal, it largely depends on a number of factors: the amount and regime of precipitation, evaporation, the inflow of water from other latitudes with currents, and the amount of fresh water delivered by rivers.
   The highest salinity is observed in tropical latitudes (according to Gembel) - 37.9%, in the North Atlantic between 20 and 30 ° N, in the South between 20 and 25 ° S. sh. The trade wind circulation dominates here, there is little precipitation, while evaporation makes up a layer of 3 m. Almost no fresh water enters.
   The salinity is somewhat less in the temperate latitudes of the Northern Hemisphere, where the waters of the North Atlantic Current rush. Salinity in equatorial latitudes is 35.2%.
   There is a change in salinity with depth: at a depth of 100-200 m it is 35%, which is associated with the subsurface Lomonosov current.
   It has been established that the salinity of the surface layer in some cases does not coincide with the salinity at depth. Salinity also drops sharply when currents of different temperatures meet. For example, south of the island of Newfoundland, when the Gulf Stream and the Labrador Current meet at a short distance, salinity drops from 35% to 31-32%
   An interesting feature of the Atlantic Ocean is the existence of fresh groundwater in it - submarine sources (according to I. S. Zetzker). One of them has long been known to sailors, it is located east of the Florida peninsula, where ships replenish fresh water. This is a 90-meter "fresh window" in the salty ocean. Water rises to the surface and hits at a depth of 40 m.
   

9. What is the difference between ocean, sea, bay and gulf?
   
   The ocean is a huge body of water. There are four oceans on Earth: Pacific, Atlantic, Indian and Arctic.
   Remember that the west coast of Asia and the east coast of America border on the Pacific Ocean, and the western coast of Ame. Riks and the east coast of Europe and Asia adjoin the Atlantic Ocean. The Indian Ocean borders the west coast of Africa, the south coast of Asia and the east coast of Australia,
   Most small from the oceans - the Arctic. It lies between the northern coasts of Asia, Europe and America.
   The depth of the ocean can be quite significant and reach the order of 4,500 meters (11,400 feet). But there are also deeper places in it - depressions. The depth of the Mariana Trench reaches 11022 meters. This is the deepest depth on earth.
   
   First of all, remember that there are two kinds of seas: the inland seas and the outer seas. The inner sea is surrounded on all sides by the continent, while the outer sea only adjoins it.
   The North Sea borders the Atlantic Ocean. An example of an inland sea would be the Mediterranean Sea.
   The words "bay" and "bay" are used interchangeably. The word "bay" is more commonly used.
   Usually these words denote the seas that approach the islands. Such, for example, is the Gulf of Biafra or the Persian Gulf.
   The depth of water in bays or bays is never too deep. And this is not at all surprising. The bottom of the sea gradually rises, and over time, the bay can become dry land.
   
   If you look at the map, you can find seas, bays and coves.

10. How many oceans are there on Earth?
    
    Look at a globe or a map of the Earth. You can see huge expanses of water there. These are the oceans. There are four in total.
    The largest of the earth's four oceans is the Pacific Ocean. He is so big that people called him Great.
    The second largest is the Atlantic Ocean, the third is the Indian Ocean, and the last is the Arctic Ocean.
    Together, all four oceans make up nine-tenths of the world's water. One third are inland seas and seas adjacent to the coasts of various countries.
    What are inland seas? They represent a part of the ocean that was once separated from it by land or islands.
    An example of an inland sea in Europe is the Mediterranean and Black Seas. They are separated from the Atlantic Ocean by the Strait of Gibraltar. Another example can be given - the Baltic Sea, which is separated from the Atlantic Ocean by the Skagerrak and Kattegat straits.
    The seas surrounding the continents are, in essence, huge bays. These are the Yellow, White or Okhotsk Sea.
    People call the seas and some very large lakes, for example, the Caspian and Aral.
    There are also oceanic seas on the map. These are parts of the ocean bounded by islands. For example, the Andaman Sea in the Indian Ocean or Sargasso in the Atlantic.
    The Atlantic Ocean extends from the east coast of Europe and Africa to the west coast of America.
    The Pacific Ocean stretches from the east coast of North and South America to the coast of Asia.
    The Indian Ocean lies between the west coast of Africa, the south coast of Asia, and the east coast of Australia.
    Between the northern coasts of America and Europe lies the Arctic Ocean.
    You can see all the oceans if you look closely at the globe.

11. 
    For a long time, scientists knew nothing about the inhabitants of the oceans who lived from the mid-Jurassic to the Eocene (which is almost 100 million years). But a recent discovery in Kansas (USA) of the remains of ancient giant fish has clarified a lot. Vera Konovalova, scientific secretary of the Paleontological Institute of the Russian Academy of Sciences, shared her opinion about the discovery with a Pravda.Ru correspondent.
    A group of scientists from Britain, the USA and Japan, led by experts from Oxford University, found representatives of a peculiar family of ancient sea giants. According to scientists, during the Jurassic and Cretaceous periods, these fish could occupy the ecological niche of modern baleen whales, feeding on small planktonic organisms. They flourished in the depths of the ocean at a time when their predecessors, the Leedsichthys, were already extinct.
    According to Dr. Kenshu Shimada, the discovery of fish remains in the center of the United States is not surprising, since 90 million years ago, modern Kansas was the most common seabed.

12. What do we know about the Dead Sea?
    
    The Dead Sea is a lake filled with salt water, stretching for 76 km in length and 16 km in width, located on the border of Jordan and Israel. The Dead Sea coast is the lowest point on land, it is 402 meters below the level of the Mediterranean Sea.
    The lake is so salty that not a single fish can live there, hence the name - the Dead Sea. It is also called Asphaltite, because its waters contain asphalt, that is, hardened oil. An excess of salts (400 grams of salt are dissolved in a liter of water of this sea) only allows you to stay on the surface of the lake, but not to swim. You can even lie there quietly reading a newspaper.
    In some places, salt precipitates and covers the bottom with a sparkling layer or sticks around the coastal stones with salt "drifts". The light yellow sand and white salt make the water appear bright blue.
    The waters and minerals of the Dead Sea have long been popular with those who want to be young, healthy and vigorous. For example, thousands of years ago, the ancient Egyptian queen Cleopatra used the water of the Dead Sea to create her "beauty balm". Mud taken from the bottom of the Dead Sea, like water, contains a huge amount of calcium, potassium, iodine, magnesium and bromine, which helps in the treatment of many diseases. People who come to relax on the shores of this unusual sea can choose different medical procedures. The Dead Sea is rich not only in mud with useful minerals, salt water, but also in sulfur springs that are nearby.
    Unfortunately, over the past century, the water level in the Dead Sea has dropped by almost 25 meters. In 1977, due to a decrease in the water level, the sea was divided into two parts - North and South. According to scientists, without intensive technical intervention, the level of the reservoir will continue to decline at a rate of about 1 meter per year and will completely disappear from the face of the earth over the next 50 years.
    Why is it impossible to drown in the Dead Sea?
    
    The Dead Sea is a truly strange and, moreover, far from the only name given by man to this one of the most unusual reservoirs on Earth.
    For the first time this sea began to be called "dead" by the ancient Greeks. The inhabitants of ancient Judea called him "salty". Arab authors referred to it as the "stinking sea".
    What is the peculiarity of this sea? In reality, it is rather a huge salt lake located between Jordan and Israel. It is formed in a depression or crack in the earth's crust that exists in this region.
    The Dead Sea stretches for about 75 km in length, reaching a width in various places from 5 to 18 km. Surprising is the fact that the surface of the Dead Sea is 400 m below sea level. In its southern part, its depth is small, but in the northern part it reaches 400 m.
    From the Dead Sea, unlike ordinary lakes, not a single river flows out, but it itself absorbs the waters of the Jordan River, which flows into it from the north, and many small streams flowing from the slopes of the surrounding hills. The only way excess water is removed from the sea is by evaporation. As a result, an unusually high concentration of mineral salts was created in its waters, such as table salt, potassium carbonate (potash), magnesium chloride and bromide, and others.
    Therefore, the Dead Sea is the saltiest sea in the world. The concentration of salts in its water is 6 times higher than in the ocean! This increases the density of the water so much that a person floats here like a cork without any effort! The Dead Sea can serve as a huge source of valuable substances. According to scientists, about 2,000,000 tons of potash are dissolved in it, which is used to produce fertilizers for the soil.
    Is there life in the Dead Sea?
    
    The Dead Sea- one of the strangest bodies of water on Earth. Millions of years ago, the water level in it was about 420 m higher than the current one and thus exceeded the level of the Mediterranean Sea.
    At that time there was life in it. However, a period of great drought followed, during which so much water evaporated from the Dead Sea that it gradually shrunk to its present size.
    One of the most striking features about the Dead Sea is the amount of salt contained in its water - 23-25 ​​percent. For comparison, let's say that ocean water is only 4-6 percent salt! If you taste the water from the Dead Sea, it will not only seem very salty to you, but it can also make you sick due to the high content of magnesium chloride. In addition, it has a similarity to oily liquids to the touch due to the large amount of calcium chloride dissolved in it.
    No animal can exist in the Dead Sea. Of course, often individual fish get there with the waters of the Jordan River flowing into it. However, due to the too high salt content, fish die, becoming the prey of birds nesting on the seashore.
    All images in this post are clickable.

13. How were the Great Lakes formed?
    
    The five Great Lakes together form the largest reservoir of fresh water on Earth. One of them is larger than any other freshwater lake in the world. More than it is only a lake with salt water - the Caspian Sea. Lake Superior, Michigan, Huron, Erie and Ontario is a Great Lakes basin that was formed by glaciers during the Ice Age. The glaciers moved in from the North, and under the weight of the glaciers the valleys became deeper and wider.
    Then, when the ice melted, there were huge deposits of sand, gravel, stones where the edge of the glacier was. With these blockages, they limited some part of the land, which used to be a valley.
    At the same time, there was no ice, it moved away, the earth began to rise, and at first in the southwest. This caused the surface of the earth in this place to change its slope. So the water flowed from the southwest to the northeast. By the time the glacier retreated, all the lakes had flowed into the St. Lawrence River and the Atlantic Ocean.
    Why did the Great Lakes fill with fresh water again? Some streams flowed into them, but the bulk of the streams flowed in the direction opposite to the lakes. The main source that feeds the Great Lakes is groundwater, which in this place comes close to the surface.
    The bottom of the lakes is a source of groundwater that maintains their level. The total area of ​​the Great Lakes and their channels is 246 sq. km.

14. Why is the Black Sea called "Black"?
    
    Everyone has long been accustomed to it and it never occurs to anyone that our Black Sea may be called something else. However, this familiar, warm and not at all frightening name of his was not always by the sea. Or rather, he had it, but a very, very long time ago.
    And really, why is the Black Sea called "Black"?
    From the most ancient Iranian texts it is clear that the sea was called "Ahshayna", which means "dark, opaque, black." And then this name was forgotten for several hundred years. To reappear? It means that it was only that this name was the most accurate and correct, since, after the lapse of time, they returned to it.
    Nevertheless, from the time when we find the first mention of the Black Sea in historical and geographical documents to the present day, several dozen names of the basin have accumulated. The great Greek colonization of this region in its written sources from the 9th-8th centuries. BC. mentioned this sea more than once. At first, the sea met the newcomers from the south, apparently, inhospitably. It hit them with severe winter storms and ice off the northern coast. In addition, the local inhabitants - the Taurians - caused significant damage to the Greek sailors. That's probably why Black Sea For a long time the Greeks called it the Inhospitable Sea (Axinos Pontos).
    Over the years, with further penetration into the Northern Black Sea region and settlement along its fertile shores, the Greeks began to call the sea Hospitable (Euxinos Pontos). The sea was marked with this name by Herodotus (V century BC), as well as on the map of Ptolemy (II century AD). We find descriptions of Pontus Euxinus in the sailing directions of that time - periplas (sea guides).
    Later, Arab geographers, using the scientific knowledge of the Black Sea of ​​ancient scientists, significantly supplemented and expanded them with new information acquired as a result of strengthening trade ties between the Middle East and the Black Sea region (the most famous trade routes ran here: “from the Varangians to the Greeks” and “The Great Silk Road ".
    Judging by historical documents, the Black Sea was then called Russian. This was noted by the Arab scholars Masudi (mid-10th century) and Edrizi (12th century). And this is not surprising, since the first documentary uses of the word "ros", "Rus" are associated precisely with the Crimea (Tavrika). Some Rus lived on the peninsula in the IX century. and later. At the same time, the educator Cyril saw books in Taurica, "written in Russian letters." But who was hiding under this name: the Scythians or the Slavs - no one can answer for sure yet. Greeks, for example, in the tenth century. they called the Russes Scythians and even Taurus-Scythians; the Arabs definitely called the Russians Slavs.
    It is only obvious that in the Indo-Aryan reading the word "ros" means "light, white." It turns out, paradoxically, but the Black Sea at one time was called the "White" Sea - Russian? So it was called for several hundred years. On some Italian maps (portolans), this name was preserved until the 15th-16th centuries. But along with this name, some peoples and travelers called the Black Sea in their own way.
    So the famous traveler Marco Polo (XIII century) called the Black Sea in his great "Book" the Great Sea. Eastern authors at the same time often mention the Black Sea under the name of Sudak (Surozh), thereby emphasizing the wide popularity of the Crimean trading center of Sudak (Surozh). The outstanding domestic traveler Athanasius Nikitin, who visited the Crimea in the 15th century, returning from his big campaign "over the three seas" to India, calls the Black Sea (the third one on its way) - Istanbul. There were other names: Cimmerian, Tauride, Crimean, Slavic, Greek, Georgian and even Armenian.
    
    Marco Polo
    Why, for example, Armenian? It can be assumed that when in the XI century. a large number of Armenians resettled in the Crimea, ousted by the Persians and Seljuk Turks from their ancestral territories, and part of the Crimea east of the present Belogorsk becomes Primorskaya Armenia - a significant economic and religious center, the sea is also called Armenian.
    In the context of the ongoing struggle for dominance over the Black Sea, the next inscription on the map disappeared along with the displacement of the next "owner" from the Black Sea region. “It flows down the sea shelf, much like a river on land. The plains in the depths of our oceans are like the deserts of the sea world, but these channels can supply the nutrients necessary for life in the desert, ”said researcher Dan Parsons (Dr. Dan Parsons), reports the Daily Telegraph. According to him, if the Black Sea river was not located under water, it would become the sixth in the world in terms of full flow.
    To explore the bottom of the Black Sea, an automatic deep-sea vehicle was used, which collected data on the characteristics of the environment. With his help, it was possible to examine the banks of the river and its floodplain. The main fundamental difference from ordinary rivers turned out to be in the features of the movement of water associated with the resistance of the environment.
    
    The river flows into the Black Sea through the Bosphorus from the Mediterranean Sea (NASA Visual Earth)
    Parsons said the river is saltier and denser than the surrounding sea water because it carries a lot of sediment. It flows along the sea floor, carrying water to the abyssal plains, just like rivers on land. Through the Sea of ​​Marmara and the Bosporus from the Mediterranean Sea, more saline waters enter the Black Sea - and it is they that fill the underwater river. For this reason, the water in the river has an extremely high concentration of salt.
    Abyssal plains in the ocean are like deserts on land. They are removed from coastal waters rich in useful substances, there is practically no life there. Feeding such underwater rivers would be very helpful.
    The authors of the study believe that underwater rivers support life in the deepest places of the oceans, far from the food-rich coastal waters. "They can be vital - like the arteries that sustain life deep in the ocean," Parsons said.
    He added that now only the first of all underwater rivers has been found. Presumably, another one is located off the coast of Brazil, where the Amazon flows into the Atlantic Ocean.
    The only significant difference between this water flow and earthly rivers is the fact that during a sharp collapse in the cavity, the water does not spiral in a clockwise direction, as the Coriolis force dictates in the Northern Hemisphere, where the Black Sea is located, but, on the contrary, counterclockwise.
    The pictures in this post are clickable.

    "When we first saw a colony of these corals, we were shocked," - says Zoe Richards (Zoe Richards), representative of the Australian center. "The huge coral was about 5 meters in diameter and 2 meters high, we have not found anything like it here before."
    Scientists say the new corals belong to the species Acropora palmata, which was thought to be extinct. Previously, it was believed that corals of this species can only be found in the Atlantic Ocean. Genetic analysis of Atlantic and Pacific corals showed that these species are close to each other, but they also have differences.
    According to scientists, Acropora palmata belong to the so-called reef-building corals and a unique ecosystem is being created here with its fish and other ocean inhabitants. Most reef-building corals are located in protected areas.
    Australian scientists say small colonies of Acropora corals have been found off the coast of the Marshall Islands before, while the new find is the largest of them. Acropora palmata corals, comparable in scale, were previously discovered in 1898 near the Fiji Islands in the Pacific Ocean.

    History of formation
    The Indian Ocean was formed at the junction of the Jurassic and Cretaceous periods as a result of the breakup of Gondwana. Then there was a separation of Africa and the Deccan from Australia with Antarctica, and later - Australia from Antarctica (in the Paleogene, about 50 million years ago).
    Bottom relief
    
    In the area of ​​​​the island of Rodrigues (Mascarene archipelago) there is a so-called. a triple junction where the Central Indian and West Indian Ridges converge, as well as the Australo-Antarctic Rise. The ridges consist of steep mountain ranges cut by normal or oblique faults with respect to the axes of the chains and divide the basalt ocean floor into 3 segments, and their tops are, as a rule, extinct volcanoes. The bottom of the Indian Ocean is covered with deposits of the Cretaceous and later periods, the thickness of which varies from several hundred meters to 2-3 km. The deepest of the numerous trenches of the ocean is the Yavan (4,500 km long and 29 km wide). The rivers flowing into the Indian Ocean carry with them huge amounts of sedimentary material, especially from the territory of India, creating high alluvial rapids.
    The coast of the Indian Ocean is replete with cliffs, deltas, atolls, coastal coral reefs and salt marshes overgrown with mangroves. Some islands - for example, Madagascar, Socotra, Maldives - are fragments of ancient continents, others - Andaman, Nicobar or Christmas Island - are of volcanic origin. The Kerguelen Plateau, located in the southern part of the ocean, also has a volcanic origin.
    Climate
    In this region, four climatic zones elongated along the parallels are distinguished. The first, located north of 10° south latitude, is dominated by a monsoonal climate with frequent cyclones moving towards the coasts. In summer, the temperature over the ocean is 28-32 °C, in winter it drops to 18-22 °C. The second zone (trade wind) is located between 10 and 30 degrees south latitude. Throughout the year, southeasterly winds blow here, especially strong from June to September. The average annual temperature reaches 25 °C. The third climatic zone lies between the 30th and 45th parallel, in subtropical and temperate latitudes. In summer, the temperature here reaches 10-22 °C, and in winter - 6-17 °C. Strong winds are characteristic from 45 degrees and south. In winter, the temperature here ranges from -16 °C to 6 °C, and in summer - from -4 °C to 10 °C.
    Characteristics of the waters
    Indian Ocean:
    Square
    surfaces
    water, million km² = 90,17
    Volume,
    million km³ = 18,07
    Medium
    depth,
    m = 1225
    The largest
    ocean depth,
    m = Sunda Trench (7209)
    The belt of Indian Ocean waters between 10 degrees north latitude and 10 degrees south latitude is called the thermal equator, where the surface water temperature is 28-29 ° C. To the south of this zone, the temperature drops, reaching -1 °C off the coast of Antarctica. In January and February, the ice along the coast of this continent melts, huge blocks of ice break off from the ice sheet of Antarctica and drift towards the open ocean.
    To the north, the temperature characteristics of the waters are determined by the monsoon air circulation. In summer, temperature anomalies are observed here, when the Somali Current cools surface waters to a temperature of 21-23 °C. In the eastern part of the ocean at the same geographical latitude, the water temperature is 28 ° C, and the highest temperature mark - about 30 ° C - was recorded in the Persian Gulf and the Red Sea. The average salinity of ocean waters is 34.8‰. The waters of the Persian Gulf, the Red and Arabian Seas are the most saline: this is due to intensive evaporation with a small amount of fresh water brought into the seas by rivers.
    Flora and fauna
    The flora and fauna of this region is unusually rich. The flora is represented by brown, red and green algae. Typical representatives of zooplankton are copepods, siphonophores and pteropods. Ocean waters are inhabited by molluscs, squids, crabs and lobsters. Fish include wrasses, bristletooths, luminous anchovies, parrotfish, surgeonfish, flying fish and poisonous lionfish. Characteristic inhabitants of the oceans are nautiluses, echinoderms, corals Fungia, Seratopia, Sinularia and lobe-finned fish. The huge charonia is unusual and beautiful. Endemic species include sea snakes and the dugong, a mammal of the siren order.
    Most of the waters of the Indian Ocean lie in the tropical and temperate zones. Warm waters are home to numerous corals, which, along with other organisms such as red algae, build coral islands. A variety of animals live in coral reefs: sponges, mollusks, crabs, echinoderms and fish. In tropical mangroves live crustaceans, mollusks and jellyfish (the diameter of the latter sometimes exceeds 1 m). The most numerous fish in the Indian Ocean are the anchovy, flying fish, tuna and shark. Often there are sea turtles, dugongs, seals, dolphins and other cetaceans. The avifauna is represented, in particular, by frigatebirds, albatrosses and several species of chinstrap penguins.
    fishing
    The importance of the Indian Ocean for the world fishing industry is small: the catches here are only 5% of the total. The main commercial fish of the local waters are tuna, sardine, anchovy, several species of sharks, barracudas and rays; Shrimps, lobsters and lobsters are also caught here.
    Transport routes
    The most important transport routes of the Indian Ocean are routes from the Persian Gulf to Europe and North America, as well as from the Gulf of Aden to India, Indonesia, Australia, Japan and China.
    Minerals
    The most important minerals of the Indian Ocean are oil and natural gas. Their deposits are found on the shelves of the Persian and Suez Gulfs, in the Bass Strait, on the shelf of the Hindustan Peninsula. On the coasts of Mozambique, the islands of Madagascar and Ceylon, ilmenite, monazite, rutile, titanite and zirconium are exploited. Off the coast of India and Australia there are deposits of barite and phosphorite, and in the shelf zones of Indonesia, Thailand and Malaysia, deposits of cassiterite and ilmenite are exploited on an industrial scale.
    States of the Indian Ocean
    In the Indian Ocean are the island states of Madagascar (the fourth largest island in the world), Comoros, Seychelles, Maldives, Mauritius, Sri Lanka. The ocean washes in the east such states: Australia, Indonesia; in the northeast: Malaysia, Thailand, Myanmar; in the north: Bangladesh, India, Pakistan; in the west: Oman, Somalia, Kenya, Tanzania, Mozambique, South Africa. In the south it borders on Antarctica. ​
    

In our country, the beginning of the study of the oceans laid Mikhail Vasilyevich Lomonosov (1711-1765). He invented a number of instruments for navigation, oceanography, geodesy, and meteorology. Of particular importance was the instrument for measuring sea currents. In 1761, Mikhail Lomonosov compiled a classification of sea ice, and two years later, a description of the Arctic Ocean. He scientifically substantiated the idea of ​​the possibility development of the Northern Sea Route.

Early Russian exploration of the distant northern and eastern sea routes in the 17th-18th centuries, carried out by expeditions equipped by decree of Peter I . Expedition of Admiral Ivan Fedorovich Kruzenshtern (1770-1846) and Admiral Yuri Fedorovich Lisyansky (1773-1837) on the sailing ships "Nadezhda" and "Neva" in 1803-1806 gg. Around the world voyages of Russian ships began to study and develop the oceans.

As a result of the research, the world map has been refined, a number of islands have been discovered, a wealth of scientific material has been collected, explored vast areas of the Pacific Ocean.

In 1815-1818. round-the-world expedition Otto Evstafievich Kotzebue (1788-1846) on the sloop "Rurik", discovered 399 islands in the Pacific Ocean and southeast of the Bering Strait - Kotzebue Bay. A well-known Russian physicist took part in the expedition (at the birth of Heinrich Friedrich Emil Lenz. Great scientific work was carried out in the Pacific Ocean, including numerous ethnographic studies on the islands of the tropical zone of the Pacific Ocean.

Russian navigator, geographer, Arctic explorer, admiral (1855), president of the Academy of Sciences in 1864-1882. Fyodor Petrovich Litke (1797-1882) described the western coast of Novaya Zemlya, the Barents and White Seas. He made two round-the-world voyages - in 1817-1819 and 1826-1829, during which he explored Kamchatka, Chukotka, the Caroline Islands, the Bonin Islands; compiled an atlas and a description of his travels, F.P. Litke - one of the creators Russian Geographical Society. A gold medal was established in his honor.

In 1819-1921. an expedition of two sloops took place - "Vostok" under the command of Thaddeus Faddeyevich Bellingshausen (1779-1852), the famous Russian navigator, discoverer of Antarctica, and "Mirny" under the command of Mikhail Petrovich Lazarev (1788-1851).They sailed towards the South Pole to solve an ancient riddle about the southern continent. Having overcome the enormous difficulties of sailing in ice conditions, the ships approached Antarctica. On January 10, 1821, the sailors of the Mirny and Vostok saw the island at the same time. It was named Peter I Island.

On January 29, 1821, the coast of Antarctica was discovered.; he was given name Alexander Coast I. This is how the greatest geographical discovery of the 19th century was made. c. - discovery of the sixth continent - Antarctica. During the sailing F. F. Bellingshausen and M. P. Lazarev rich oceanological material was collected, mainly in the latitudes of the southern hemisphere, especially in the waters of the Antarctic.

Our domestic expeditions of the 19th century, carried out on sailing ships, were of great importance for the study of the World Ocean.

In 1815, Ivan Fedorovich Kruzenshtern, on the basis of Russian research, compiled the first Atlas of the South Sea (Pacific Ocean). Russian sailors and scientists carried out 25 circumnavigations, first described the trade wind countercurrent in the Pacific Ocean. Other currents were also discovered, and a variety of valuable information on oceanology was collected. Huge expanses of then almost unknown regions in the north and south of the Pacific Ocean are marked on the map; many corrections have been made to the maps of other oceans and seas.

Abroad, the chronicle of modern oceanology has been conducted since the three-year expedition English vessel "Challenger", which made a round-the-world voyage in 1872-1876. Organizer of a special research expedition Charles Thomson was on the Challenger. The scientific materials on the World Ocean collected by the expedition were processed and studied for 20 years. The publication of the research results was completed in 1895 and amounted to 50 large volumes, which are still of great importance in the knowledge of the ocean. The expedition gave a lot of new information about the physical, chemical and biological phenomena and processes taking place in the ocean.

From a wonderful galaxy Russian oceanographers of the end 19th century and early XX in. the name of Stepan Osipovich Makarov (1848-1904) stands out in particular- oceanographer, polar explorer, shipbuilder, vice admiral of the naval commander, inventor and theorist of shipbuilding, tireless explorer of the oceans and seas. His motto was: "At sea means at home." He is one of founders of national oceanology. In 1895 he developed the Russian semaphore alphabet. In 1886-1889. sail-motor corvette "Vityaz" under the command of S. O. Makarov made a round-the-world voyage, during which oceanographic observations and research were carried out along all navigation routes.

During the three years of navigation, a huge scientific work was carried out. Conducted oceanographic studies are described in the book "The Knight" and the Pacific Ocean, published in 1894. and now known all over the world. The merits of the expedition are highly appreciated by world science. Name "Vityaz" engraved on the pediment of the Oceanographic Institute in Monaco among the names of the ten most famous ships associated with the study and development of the oceans.

Stepan Osipovich Makarov was also a polar explorer. From the world's first powerful icebreaker "Ermak", built according to the project of Stepan Osipovich Makarov, for a number of years the ice of the Arctic basin and the depths of the ocean were studied, magnetic and other observations were made. On board the Yermak, the mechanical properties of sea ice, its structure, and density were carefully studied. . The work of S. O. Makarov "Ermak" in the ice"- a reference book for every modern oceanologist.

At the beginning of the XX century. work began on a comprehensive oceanographic study of the fishing areas of the World Ocean. An important place among them is occupied by the works of the zoologist Nikolai Mikhailovich Knipovich (1862-1939) in the Barents Sea which laid the foundation for a systematic comprehensive study of the northern seas. He worked on the study of the fauna and physical geography of the White Sea.

The results of Russian pre-revolutionary studies are summed up in the capital work of the Russian and Soviet oceanographer and geographer Yuli Mikhailovich Shokalsky (185 G -1940) "Oceanography", published in 1917

On March 10, 1921, a decree signed by V. I. Lenin was issued on the organization of an oceanographic institution called the Floating Marine Research Institute (Plavmornin). Later it was transformed into the Polar Research Institute of Marine Fisheries and Oceanography. N. M. Knipovich. The Institute is located in Murmansk. His task included a comprehensive and systematic study of the northern seas, their islands, coasts, biological and other resources of the sea. The institute was served by the first Soviet research vessel "Perseus"- small (with a displacement of 550 tons), but well equipped, with several scientific laboratories,

In the 1920s and 1930s, the main efforts of Soviet oceanologists were directed towards a comprehensive study of the seas washing the shores of the USSR.

The research materials of the second International Polar Year made it possible to draw important scientific and practical conclusions regarding the improvement of the accuracy of ice and weather forecasts for the development of marine fisheries in the Far North.

Aroused great interest in the world expedition on the icebreaking steamer "Sibiryakov", for the first time in history, made in 1932 for one sea navigation through navigation along the Northern Sea Route from Arkhangelsk to Vladivostok. It was to pave the way, which many navigators tried to find for several centuries.

The thirties were the years of the development of the Arctic and the Northern Sea Route. Numerous expeditions, including those led by a well-known geophysicist and geographer Otto Yulievich Schmidt (1891 -1956), in terms of the breadth of scientific programs, the importance of their results for the national economy and science, and at the same time, in terms of the complexity of the natural conditions in which they were carried out, they were practically unparalleled. Two events stand out in particular: the operation of the first drifting scientific station "North Pole" in 1937-1938, which later became known as "SP-1", and the drift of the icebreaker steamship "Georgy Sedov" in 1937-1940.

By 1937, a significant amount of information had been accumulated about the nature and regime of the ice cover, about the weather in the marginal seas of the Arctic. But there was almost no information about natural phenomena in the Central Arctic, which delayed the development of the Northern Sea Route. This "white spot" was supposed to be explored by the scientific station "SP-1" landed on the ice floe. The polar explorers Ivan Papanin, Pyotr Shirshov, Evgeny Fedorov and Ernst Krenkel worked as part of the station. The researchers measured the depths of the Arctic Ocean, and for the first time it was established ocean depth at the North Pole, measured at different horizons temperature, flow, studied composition of water, determined the force of gravity, carried out meteorological, magnetometric, biological and other observations. The results of the work of the station "SP-1" refuted many ideas of world scientists about the Arctic.

It was found that there are no islands and land in the region of the North Pole, but there is life. Installed perfectly new patterns in weather phenomena and atmospheric processes in the Central Arctic. There was an opinion among Scientists that throughout the year, stable cold weather with high pressure persists over the polar basin - the so-called "cold cap". It turned out that a relatively warm mass of air circulates in the region of the pole, and cyclones occur just as often, as on the mainland, bringing unstable weather, rain, snow, fog, strong winds.

In 1937, the icebreaking ships Sadko, Malygin and Georgy Sedov were caught in ice near the New Siberian Islands.. The icebreaker "Ermak" managed to bring the "Sadko" and "Malygin" out of the ice captivity. The icebreaker "Georgy Sedov" crossed the entire Central Arctic Basin with drifting ice and in 1940 was taken out to the Greenland Sea.A simple icebreaking ship, not prepared for the conditions of a long ice drift, managed not only to repeat the world famous drift on the Fram. Fridtjof Nansen (1893-1896) - Norwegian polar explorer, zoologist, founder of a new science - physical oceanography, but also closer to the North Pole. In high latitudes, Georgy Sedov stayed twice as long as the Norwegian Fram, and three times longer than the SP-1 station. Soviet sailors "George Sedov"Under the command of Captain K.S. Badigin, it was possible to overcome the difficulties of ice drift.

The scientific data obtained as a result of the drifts of the SP-1 and Georgy Sedov played an important role in the development of Arctic navigation and transformation of the Northern Sea Route into an operating transport route.

The post-war period is marked by an intensive, broad and comprehensive study of all regions of the World Ocean. A number of scientific institutions of the oceanological profile were created. One of the station drift participants "SP-1" Pyotr Petrovich Shirshov organized and headed the Institute of Oceanology of the USSR Academy of Sciences. Now the institute bears his name. In 1949, an expeditionary research vessel of this Institute "Vityaz" - the flagship of the Soviet research fleet. Studying nature, revealing its innermost secrets, he traveled to unexplored regions of the World Ocean, approached the shores of distant islands, explored the greatest depths, was in the Bermuda Triangle, went towards typhoons and storms.

The famous Russian scientist Nikolai Nikolaevich Miklukho-Maclay sailed on the first Vityaz, Russian ethnographer, anthropologist, biologist and traveler who studied the indigenous population of Southeast Asia, Australia and Oceania (1870-1880s).

On the second Vityaz, S. O. Makarov explored the Pacific Ocean. Third "Vityaz" took part in many international expeditions. With the third "Vityaz""A whole era of discoveries and research in the World Ocean is connected. During the expedition, life was discovered at maximum depths, deep-sea ridges, trenches, mountains, currents were discovered, the greatest depth of the World Ocean was determined. G.

In 1982, the fourth Vityaz entered service.» is the world's most modern research vessel, equipped with the latest science and technology. On board there are manned and remote-controlled underwater vehicles and other deep-sea equipment that allows researchers to descend into the depths of the ocean.

Along with the Vityaz, the secrets of the seas and oceans are explored by many modern ships of science: "Mikhail Lomonosov", "Academician Kurchatov", "Dmitry Mendeleev", "Academician Vernadsky", "Academician Sergei Korolev", "Cosmonaut Vladimir Komarov" and etc. They are rightly called modern research floating institutes.

Man has been studying the ocean for a long time, but still the ocean holds many secrets. The complex configuration of coasts, variable depths, changing weather and climatic conditions, other terrestrial and space factors affecting the nature of the ocean - all this makes research difficult. Even his “inventory” has not been completed. Specialists annually discover and describe new seamounts, gorges, plains, as well as processes and phenomena occurring in the ocean, discover species of animals and plants unknown to science, discover new mineral wealth. To the aid of the explorers of the depths came space technology.

What sciences study the oceans!

Many sciences are engaged in the study and research of the World Ocean. The main ones are oceanology, which studies various physical, chemical, biological, geological processes and their relationship with the atmosphere. The ocean sciences are ocean physics, ocean chemistry, ocean biology and other related disciplines.

Ocean physics is a science that studies the patterns of interaction between the ocean and the atmosphere (hydrothermal dynamics, acoustics and optics of the ocean, the study of its radioactivity and the electromagnetic field in it).

Ocean chemistry is a science that establishes the patterns of exchange and transformation of a chemical substance in the ocean and the formation of its stability.

Ocean biology is a science that investigates the patterns of formation and assessment of biomass and annual productivity of the most important species of organisms, the possibilities of controlling the biological productivity of the ocean. Ocean geology is the science of identifying the patterns of development of geological processes at the bottom and under the bottom of the ocean and the formation of mineral deposits.

Oceanography is a science that studies and describes the physical and chemical properties of the aquatic environment, the patterns of physical and chemical processes and phenomena in the World Ocean in their interaction with the atmosphere, dry land and the bottom.

One of the branches of oceanology - marine hydrography. It is engaged in the study of the seabed and the possibilities of using marine natural resources. As a result hydrographic works are created sea charts and sailing directions (guides with recommended courses), descriptions of coasts and ports, anchorages, lighthouses and navigational signs; without these benefits, not a single ship goes to sea.

The World Ocean, covering 71% of the Earth's surface, strikes with the complexity and variety of processes developing in it.

From the surface to the greatest depths, the waters of the ocean are in continuous motion. These complex movements of water from huge ocean currents to the smallest eddies are excited by tide-forming forces and serve as a manifestation of the interaction of the atmosphere and the ocean.

The water mass of the ocean at low latitudes accumulates heat received from the sun and transfers this heat to high latitudes. The redistribution of heat, in turn, excites certain atmospheric processes. So, in the area of ​​convergence of cold and warm currents in the North Atlantic, powerful cyclones arise. They reach Europe and often determine the weather throughout its space up to the Urals.

The living matter of the ocean is very unevenly distributed over the depths. In different regions of the ocean, biomass depends on climatic conditions and the supply of nitrogen and phosphorus salts to surface waters. The ocean is home to a great variety of plants and animals. From bacteria and unicellular green phytoplankton algae to the largest mammals on earth - whales, whose weight reaches 150 tons. All living organisms form a single biological system with their own laws of existence and evolution.

Loose sediments accumulate very slowly at the bottom of the ocean. This is the first stage in the formation of sedimentary rocks. In order for geologists working on land to be able to correctly decipher the geological history of a particular territory, it is necessary to study in detail the modern processes of sedimentation.

As it turned out in recent decades, the earth's crust under the ocean has great mobility. At the bottom of the ocean, mountain ranges, deep rift valleys, and volcanic cones are formed. In a word, the bottom of the ocean "lives" violently, and often there are such strong earthquakes that huge devastating tsunami waves rapidly run across the surface of the ocean.

Trying to explore the nature of the ocean - this grandiose sphere of the earth, scientists face certain difficulties, to overcome which they have to apply the methods of all the main natural sciences: physics, chemistry, mathematics, biology, geology. Oceanology is usually spoken of as a union of various sciences, a federation of sciences united by the subject of study. In this approach to the study of the nature of the ocean, there is a natural desire to penetrate deeper into its secrets and an urgent need to deeply and comprehensively know the characteristic features of its nature.

These tasks are very complex, and they have to be solved by a large team of scientists and specialists. In order to imagine exactly how this is done, consider the three most relevant areas of ocean science:

• ocean-atmosphere interaction;
• the biological structure of the ocean;
• ocean floor geology and its mineral resources.

The long-term tireless work of the oldest Soviet research vessel "Vityaz" has completed. It arrived at the Kaliningrad sea port. The 65th farewell flight, which lasted more than two months, has ended.

Here is the last "traveling" entry in the ship's log of a veteran of our oceanographic fleet, who, in thirty years of voyages, left more than a million miles behind the stern.

In a conversation with a Pravda correspondent, the head of the expedition, Professor A. A. Aksenov, noted that the 65th flight of the Vityaz, like all previous ones, was successful. During complex research in the deep-sea regions of the Mediterranean Sea and the Atlantic Ocean, new scientific data have been obtained that will enrich our knowledge of the life of the sea.

Vityaz will be temporarily based in Kaliningrad. It is assumed that then it will become the base for the creation of the Museum of the World Ocean.

For several years, scientists from many countries have been working on the international project GAAP (Global Atmospheric Process Research Program). The aim of this work is to find a reliable method for weather forecasting. There is no need to explain how important this is. It will be possible to know in advance about drought, floods, downpours, strong winds, heat and cold ...

So far, no one can give such a forecast. What is the main difficulty? It is impossible to accurately describe the processes of interaction between the ocean and the atmosphere with mathematical equations.

Nearly all of the water that falls on land as rain and rain enters the atmosphere from the surface of the ocean. Ocean waters in the tropics become very hot, and currents carry this heat to high latitudes. Over the ocean there are huge whirlwinds - cyclones that determine the weather on land.

The ocean is the kitchen of the weather... But there are very few permanent weather stations in the ocean. These are a few islands and several automatic floating stations.

Scientists are trying to build a mathematical model of the interaction between the ocean and the atmosphere, but it must be real and accurate, and this lacks many data on the state of the atmosphere over the ocean.

The solution was found to be very accurate and continuous measurements from ships, aircraft and meteorological satellites in a small area of ​​the ocean. Such an international experiment called "Tropex" was carried out in the tropical zone of the Atlantic Ocean in 1974, and very important data were obtained for building a mathematical model.

It is necessary to know the whole system of currents in the ocean. Currents carry heat (and cold), nutritious mineral salts necessary for the development of life. A long time ago, sailors began to collect information about the currents. It began in the 15th-16th centuries, when sailing ships took to the open ocean. Nowadays, all sailors know that there are detailed maps of surface currents, and use them. However, in the last 20-30 years, discoveries have been made that have shown how inaccurate current maps are and how complex the overall picture of ocean circulation is.

In the equatorial zone of the Pacific and Atlantic oceans, powerful deep currents were explored, measured and mapped. They are known as the Cromwell Current in the Pacific and the Lomonosov Current in the Atlantic Ocean.

In the west of the Atlantic Ocean, the deep Antilo-Guiana countercurrent was discovered. And under the famous Gulf Stream turned out to be the Counter-Gulf Stream.

In 1970, Soviet scientists conducted a very interesting study. A series of buoy stations have been installed in the tropical zone of the Atlantic Ocean. Currents at various depths were continuously recorded at each station. The measurements lasted half a year, and hydrological surveys were periodically performed in the area of ​​measurements to obtain data on the general pattern of water movement. After processing and summarizing the measurement materials, a very important general pattern emerged. It turns out that the previously existing idea of ​​a relatively uniform nature of the constant trade wind current, which is excited by the north trade winds, does not correspond to reality. There is no such stream, this huge river in liquid banks.

Huge whirlpools, whirlpools, tens and even hundreds of kilometers in size, move in the zone of the trade wind current. The center of such a vortex moves at a speed of about 10 cm/s, but on the periphery of the vortex, the flow velocity is much higher. This discovery of Soviet scientists was later confirmed by American researchers, and in 1973 similar eddies were traced in Soviet expeditions operating in the North Pacific Ocean.

In 1977-1978. A special experiment was set up to study the eddy structure of currents in the area of ​​the Sargasso Sea in the west of the North Atlantic. Over a large area, Soviet and American expeditions continuously measured currents for 15 months. This huge amount of material has not yet been fully analyzed, but the formulation of the problem itself required massive specially designed measurements.

Particular attention to the so-called synoptic eddies in the ocean is due to the fact that it is the eddies that carry the largest share of the current energy. Consequently, their careful study can bring scientists much closer to solving the problem of long-range weather forecasting.

Another most interesting phenomenon associated with ocean currents has been discovered in recent years. To the east and west of the powerful Gulf Stream, very stable so-called rings (rings) were found. Like a river, the Gulf Stream has strong meanders. In some places, the meanders close, and a ring is formed, in which the temperature of the hearth differs sharply at the periphery and in the center. Such rings have also been traced on the periphery of the powerful Kuroshio current in the northwestern part of the Pacific Ocean. Special observations of rings in the Atlantic and Pacific oceans have shown that these formations are very stable, maintaining a significant difference in water temperature on the periphery and inside the ring for 2-3 years.

In 1969, for the first time, special probes were used to continuously measure temperature and salinity at various depths. Prior to this, the temperature was measured with mercury thermometers at several points at different depths, and water was raised from the same depths in bottles. Then the salinity of the water was determined and the salinity and temperature values ​​were plotted on a graph. The depth distribution of these water properties was obtained. Measurements at individual points (discrete) did not even allow us to assume that the water temperature changes with depth as complexly as it was shown by continuous measurements with the probe.

It turned out that the entire water mass from the surface to great depths is divided into thin layers. The difference in temperature between adjacent horizontal layers reaches several tenths of a degree. These layers, from several centimeters to several meters thick, sometimes exist for several hours, sometimes disappear in a few minutes.

The first measurements, made in 1969, seemed to many to be a random phenomenon in the ocean. It cannot be, the skeptics said, that the mighty ocean waves and currents do not mix the water. But in subsequent years, when the sounding of the water column with precise instruments was carried out throughout the ocean, it turned out that the thin-layered structure of the water column was found everywhere and always. The reasons for this phenomenon are not entirely clear. So far, they explain it this way: for one reason or another, numerous fairly clear boundaries appear in the water column, separating layers with different densities. At the boundary of two layers of different density, internal waves very easily arise, which mix the water. In the process of destruction of internal waves, new homogeneous layers arise, and the boundaries of the layers are formed at other depths. So this process is repeated many times, the depth and thickness of layers with sharp boundaries change, but the general nature of the water column remains unchanged.

In 1979, the pilot phase of the International Program for the Study of Global Atmospheric Processes (PGAP) began. Several dozen ships, automatic observation stations in the ocean, special aircraft and meteorological satellites, all this mass of research facilities is working throughout the entire space of the World Ocean. All participants in this experiment work according to a single coordinated program so that, by comparing the materials of the international experiment, it would be possible to build a global model of the state of the atmosphere and ocean.

If we take into account that in addition to the general task - the search for a reliable method of long-term weather forecasting, it is necessary to know a lot of particular facts, then the general task of ocean physics will seem very, very complicated: measurement methods, instruments, the operation of which is based on the use of the most modern electronic circuits, are quite difficult processing of the information received with the obligatory use of a computer; construction of very complex and original mathematical models of processes developing in the water column of the ocean and at the boundary with the atmosphere; setting up extensive experiments in characteristic regions of the ocean. These are the general features of modern research in the field of ocean physics.

Special difficulties arise in the study of living matter in the ocean. Relatively recently, the necessary materials were obtained for a general characterization of the biological structure of the ocean.

Only in 1949 was life discovered at depths of more than 6000 m. Later, the deep-sea fauna - the fauna of the ultraabyssal - turned out to be the most interesting object of special research. At such depths, the conditions of existence are very stable on a geological time scale. Based on the similarity of the ultra-abyssal fauna, it is possible to establish the former connections of individual oceanic depressions and restore the geographical conditions of the geological past. So, for example, comparing the deep-sea fauna of the Caribbean Sea and the Eastern Pacific Ocean, scientists have found that in the geological past there was no Isthmus of Panama.

Somewhat later, a striking discovery was made - a new type of animal, pogonophores, was discovered in the ocean. A thorough study of their anatomy, a systematic classification made up the content of one of the outstanding works in modern biology - A. V. Ivanov's monograph "Pogonophores". These two examples show how difficult it turned out to be to study the distribution of life in the ocean, and even more so the general laws governing the functioning of biological systems in the ocean.

Comparing disparate facts, comparing the biology of the main groups of plants and animals, scientists have come to important conclusions. The total biological production of the World Ocean turned out to be somewhat less than a similar value characterizing the entire land area, despite the fact that the ocean area is 2.5 times larger than the land area. This is due to the fact that the areas of high biological productivity are the periphery of the ocean and the areas of deep water rise. The rest of the ocean is an almost lifeless desert, where only large predators can be found. Separate oases in the ocean desert are only small coral atolls.

Another important finding concerns the general characteristics of food chains in the ocean. The first link in the food chain is unicellular green algae phytoplankton. The next link is zooplankton, then planktivorous fish and predators. Milking animals - benthos, which are also food for fish, are of significant importance.

Reproduction in each link of the food price is such that the produced biomass is 10 times higher than its consumption. In other words, 90% of, for example, phytoplankton dies naturally and only 10% serves as food for zooplankton. It has also been established that zooplankton crustaceans perform vertical diurnal migrations in search of food. More recently, it was possible to detect clumps of bacteria in the diet of zooplankton crustaceans, and this type of food accounted for up to 30% of the total volume. The general result of modern studies of ocean biology is that an approach has been found and the first block mathematical model of the ecological system of the open ocean has been built. This is the first step towards the artificial regulation of ocean biological productivity.

What methods do biologists use in the ocean?

First of all, a variety of fishing gear. Small plankton organisms are caught with special cone nets. As a result of fishing, an average amount of plankton is obtained in weight units per unit volume of water. These nets can catch individual horizons of the water column or "filter" water from a given depth to the surface. Bottom animals are caught by various tools towed along the bottom. Fish and other nekton organisms are caught by mid-depth trawls.

Peculiar methods are used to study the food relationships of various plankton groups. Organisms “tag” with radioactive substances and then determine the amount and rate of grazing in the next link in the food chain.

In recent years, physical methods have been used to indirectly determine the amount of plankton in water. One of these methods is based on the use of a laser beam, which, as it were, probes the surface layer of water in the ocean and provides data on the total amount of phytoplankton. Another physical method is based on the use of the ability of plankton organisms to glow - bioluminescence. A special bathometer-probe is immersed in water, and as it sinks, the intensity of bioluminescence is recorded as an indicator of the amount of plankton. These methods very quickly and completely characterize the distribution of plankton in a variety of sounding points.

An important element in the study of the biological structure of the ocean is chemical research. The content of biogenic elements (mineral salts of nitrogen and phosphorus), dissolved oxygen, and a number of other important characteristics of the habitat of organisms are determined by chemical methods. Careful chemical determinations are especially important when studying highly productive coastal regions - upwelling zones. Here, with regular and strong winds from the shore, there is a strong collapse of water, accompanied by the rise of deep waters and their spread in the shallow area of ​​the shelf. Deep waters contain in dissolved form a significant amount of mineral salts of nitrogen and phosphorus. As a result, phytoplankton flourishes in the upwelling zone and, ultimately, an area of ​​commercial concentrations of fish is formed.

The prediction and registration of the specific nature of the habitat in the upwelling zone is carried out by chemical methods. Thus, in biology, the question of acceptable and applicable methods of research is being solved in our time in a complex way. While widely using traditional methods of biology, researchers are increasingly using the methods of physics and chemistry. The processing of materials, as well as their generalization in the form of optimized models, is carried out using the methods of modern mathematics.

In the field of ocean geology, so many new facts have been obtained over the past 30 years that many traditional ideas have had to be drastically changed.

Just 30 years ago, measuring the depth of the ocean floor was extremely difficult. It was necessary to lower a heavy lot with a load suspended on a long steel cable into the water. At the same time, the results were often erroneous, and the points with measured depths were separated from one another by hundreds of kilometers. Therefore, the idea of ​​the vast expanses of the ocean floor as giant plains dominated.

In 1937, for the first time, a new method of measuring depths was applied, based on the effect of sound signal reflection from the bottom.

The principle of measuring depth with an echo sounder is very simple. A special vibrator mounted in the lower part of the ship's hull emits pulsating acoustic signals. The signals are reflected from the bottom surface and are picked up by the receiving device of the echo sounder. The round-trip time of the signal depends on the depth, and a continuous bottom profile is drawn on the tape as the ship moves. A series of such profiles, separated by relatively small distances, makes it possible to draw lines of equal depths - isobaths on the map and depict the bottom relief.

Depth measurements with an echo sounder have changed scientists' previous ideas about the topography of the ocean floor.

What does it look like?

A strip extending from the shore is called the continental shelf. Depths on the continental shelf usually do not exceed 200-300 m.

In the upper zone of the continental shelf there is a continuous and rapid transformation of the relief. The coast recedes under the onslaught of waves, and at the same time large accumulations of detrital material appear under the water. It is here that large deposits of sand, gravel, pebbles are formed - an excellent building material, crushed and sorted by nature itself. Various spits, embankments, bars, in turn, build up the coast in another place, separate lagoons, block river mouths.

In the tropical zone of the ocean, where the water is very clean and warm, grandiose coral structures grow - coastal and barrier reefs. They stretch for hundreds of kilometers. Coral reefs serve as a refuge for a great variety of organisms and together with them form a complex and extraordinary biological system. In a word, the upper zone of the shelf "lives" with a stormy geological life.

At depths of 100-200 m, geological processes seem to freeze. The relief becomes leveled, there are many bedrock outcrops at the bottom. The destruction of the rocks is very slow.

On the outer edge of the shelf, facing the ocean, the bottom surface slope becomes steeper. Sometimes slopes reach 40-50°. This is the continental slope. Its surface is cut by underwater canyons. Tense, sometimes catastrophic processes take place here. Silt accumulates on the slopes of underwater canyons. At times, the stability of the accumulations is suddenly broken, and a mud stream falls down along the bottom of the canyon.

The mud flow reaches the mouth of the canyon, and here the main mass of sand and large debris, being deposited, forms an alluvial cone - an underwater delta. A turbid flow goes beyond the continental foot. Quite often, separate alluvial fans unite, and a continuous strip of loose sediments of great thickness forms at the continental foot.

53% of the bottom area is occupied by the ocean bed, the area that until recently was considered a plain. In fact, the relief of the ocean floor is quite complex: uplifts of various structures and origins divide it into huge basins. The dimensions of oceanic basins can be estimated from at least one example: the northern and eastern basins of the Pacific Ocean cover an area larger than the entire North America.

A large area of ​​the basins themselves is dominated by a hilly relief, sometimes there are separate seamounts. The height of the mountains of the ocean reaches 5-6 km, and their peaks often rise above the water.

In other areas, the ocean floor is crossed by huge gently sloping swells several hundred kilometers wide. Usually, volcanic islands are located on these shafts. In the Pacific Ocean, for example, there is the Hawaiian Wall, on which there is a chain of islands with active volcanoes and lava lakes.

Volcanic cones rise from the bottom of the ocean in many places. Sometimes the top of the volcano reaches the surface of the water, and then an island appears. Some of these islands are gradually being destroyed and hidden under water.

In the Pacific Ocean, several hundred volcanic cones have been discovered with clear traces of wave action on flat tops, submerged to a depth of 1000-1300 m.

The evolution of volcanoes may be different. Reef-forming corals settle at the top of the volcano. With slow sinking, corals build up a reef, and over time, a ring island is formed - an atoll with a lagoon in the middle. Coral reef growth can take a very long time. Drilling has been carried out on some Pacific atolls to determine the thickness of the coral limestone sequence. It turned out that it reaches 1500. This means that the top of the volcano descended slowly - for about 20 thousand years.

By studying the bottom topography and the geological structure of the ocean's solid crust, scientists have come to some new conclusions. The earth's crust under the ocean floor turned out to be much thinner than on the continents. On the continents, the thickness of the Earth's solid shell - the lithosphere - reaches 50-60 km, and in the ocean it does not exceed 5-7 km.

It also turned out that the lithosphere of land and ocean is different in rock composition. Under a layer of loose rocks - products of the destruction of the land surface lies a powerful granite layer, which is underlain by a basalt layer. There is no granite layer in the ocean, and loose deposits lie directly on the basalts.

Even more important was the discovery of a grandiose system of mountain ranges at the bottom of the ocean. The mountain system of mid-ocean ridges stretches across all the oceans for 80,000 km. In size, underwater ranges are comparable only to the greatest mountains on land, such as the Himalayas. The crests of underwater ridges are usually cut along by deep gorges, which were called rift valleys, or rifts. Their continuation can also be traced on land.

Scientists have realized that the global rift system is a very important phenomenon in the geological development of our entire planet. A period of careful study of the system of rift zones began, and soon such significant data were obtained that there was a sharp change in ideas about the geological history of the Earth.

Now scientists have again turned to the half-forgotten hypothesis of continental drift, expressed by the German scientist A. Wegener at the beginning of the century. A careful comparison of the contours of the continents separated by the Atlantic Ocean was made. At the same time, the geophysicist J. Bullard combined the contours of Europe and North America, Africa and South America not along the coastlines, but along the median line of the continental slope, approximately along the 1000 m isobath. The outlines of both ocean shores coincided so exactly that even inveterate skeptics could not doubt in the actual enormous horizontal movement of the continents.

Particularly convincing were the data obtained during geomagnetic surveys in the area of ​​mid-ocean ridges. It turned out that the erupted basaltic lava gradually shifted to both sides of the crest of the ridge. Thus, direct evidence was obtained of the expansion of the oceans, the spreading of the earth's crust in the rift region and, in accordance with this, the drift of the continents.

Deep drilling in the ocean, which has been carried out for several years from the American ship Glomar Challenger, has again confirmed the fact of the expansion of the oceans. They even established the average value of the expansion of the Atlantic Ocean - a few centimeters per year.

It was also possible to explain the increased seismicity and volcanism at the periphery of the oceans.

All these new data formed the basis for the creation of a hypothesis (often called a theory, its arguments are so convincing) of tectonics (mobility) of lithospheric plates.

The original formulation of this theory belongs to the American scientists G. Hess and R. Dietz. Later it was developed and supplemented by Soviet, French and other scientists. The meaning of the new theory is reduced to the idea that the rigid shell of the Earth - the lithosphere - is divided into separate plates. These plates experience horizontal movements. The forces that set the lithospheric plates in motion are generated by convective currents, i.e., currents of the deep fiery-liquid substance of the Earth.

The spreading of plates to the sides is accompanied by the formation of mid-ocean ridges, on the crests of which gaping rift cracks appear. Through the rifts there is an outpouring of basaltic lava.

In other areas, lithospheric plates converge and collide. In these collisions, as a rule, a subduction of the edge of one plate under another is born. On the periphery of the oceans, such modern underthrust zones are known, where strong earthquakes often occur.

The theory of lithospheric plate tectonics is confirmed by many facts obtained over the past fifteen years in the ocean.

The general basis of modern ideas about the internal structure of the Earth and the processes occurring in its depths is the cosmogonic hypothesis of Academician O. Yu. Schmidt. According to him, the Earth, like other planets of the solar system, was formed by sticking together the cold matter of a dust cloud. Further growth of the Earth occurred by capturing new portions of the meteorite substance when passing through a dust cloud that once surrounded the Sun. As the planet grew, heavy (iron) meteorites sank and light (stone) meteorites emerged. This process (separation, differentiation) was so powerful that inside the planet the substance was melted and divided into a refractory (heavy) part and a fusible (lighter) part. At the same time, radioactive heating in the inner parts of the Earth also acted. All these processes led to the formation of a heavy inner core, a lighter outer core, lower and upper mantle. Geophysical data and calculations show that a huge energy is hidden in the bowels of the Earth, which is really capable of decisive transformations of the solid shell - the lithosphere.

Based on the cosmogonic hypothesis of O. 10. Schmidt, Academician A. P. Vinogradov developed a geochemical theory of the origin of the ocean. A.P. Vinogradov, through precise calculations, as well as experiments to study the differentiation of the molten substance of meteorites, established that the water mass of the ocean and the Earth's atmosphere was formed in the process of degassing of the substance of the upper mantle. This process continues to this day. In the upper mantle, indeed, a continuous differentiation of matter occurs, and its most fusible part penetrates the surface of the lithosphere in the form of basalt lava.

Ideas about the structure of the earth's crust and its dynamics are gradually being refined.

In 1973 and 1974 an unusual underwater expedition was carried out in the Atlantic Ocean. In a pre-selected area of ​​the Mid-Atlantic Ridge, deep-sea dives of submersibles were carried out and a small but very important area of ​​the ocean floor was studied in detail.

Exploring the bottom from surface vessels during the preparation of the expedition, the scientists studied the bottom topography in detail and discovered an area inside which there was a deep gorge, cutting along the crest of an underwater ridge - a rift valley. In the same area, there is a well-pronounced transform fault, which is transverse with respect to the crest of the ridge and the rift gorge.

Such a typical bottom structure - a rift gorge, a transform fault, young volcanoes - was surveyed from three submarines. The expedition was attended by the French bathyscaphe "Archimedes" with the special vessel "Marseille le Bian" providing its operation, the French submarine "Siana" with the vessel "Norua", the American research vessel "Knorr", the American submarine "Alvin" with the vessel "Lulu" .

A total of 51 deep dives were made over two seasons.

When performing deep-sea dives up to 3000 m, the crews of submarines encountered some difficulties.

The first thing that initially greatly complicated the research was the inability to determine the location of the underwater vehicle in conditions of a highly dissected terrain.

The underwater vehicle had to move, keeping a distance of no more than 5 m from the bottom. On steep slopes and crossing narrow valleys, the bathyscaphe and submarines could not use the system of acoustic beacons, as seamounts prevented the passage of signals. For this reason, an on-board system was put into operation on support vessels, with the help of which the exact location of the submarine was determined. From the support vessel, they monitored the underwater vehicle and directed its movement. Sometimes there was a direct danger to the underwater vehicle, and once such a situation arose.

On July 17, 1974, the Alvin submarine literally got stuck in a narrow crack and made attempts to get out of the trap for two and a half hours. The Alvin crew showed amazing resourcefulness and composure - after leaving the trap, they did not surface, but continued research for another two hours.

In addition to direct observations and measurements from underwater vehicles, when photographing and collecting samples, drilling was done in the expedition area from the famous special vessel "Glomar Challenger".

Finally, geophysical measurements were regularly carried out on board the Knorr research vessel, supplementing the work of underwater vehicle observers.

As a result, 91 km of route observations were made in a small area of ​​the bottom, 23 thousand photographs were taken, more than 2 tons of rock samples were collected and more than 100 videos were made.

The scientific results of this expedition (it is known as "Famous") are very important. For the first time, submersibles were used not just for observations of the underwater world, but for purposeful geological research, similar to those detailed surveys that geologists conduct on land.

For the first time, direct evidence was obtained for the movement of lithospheric plates along the boundaries. In this case, the boundary between the American and African plates was investigated.

The width of the zone was determined, which is located between moving lithospheric plates. Unexpectedly, it turned out that this zone, where the earth's crust forms a system of cracks and where basalt lava flows out onto the bottom surface, that is, a new earth's crust is formed, this zone has a width of less than a kilometer.

A very important discovery was made on the slopes of underwater hills. In one of the dives of the Siana submersible, fissured loose fragments were found on a hillside, very different from various fragments of basaltic lava. After the Siana surfaced, it was found that it was manganese ore. A more detailed survey of the area of ​​distribution of manganese ores led to the discovery of an ancient hydrothermal deposit on the bottom surface. Repeated dives yielded new materials proving that indeed, due to the emergence of thermal waters from the depths of the bottom, iron and manganese ores lie in this small section of the bottom.

During the expedition, many technical problems arose and there were failures, but the precious experience of purposeful geological research, gained over two seasons, is also an important result of this extraordinary oceanological experiment.

Methods for studying the structure of the earth's crust in the ocean differ in some features. The bottom relief is studied not only with the help of echo sounders, but also with side-scan locators and special echo sounders, which give a picture of the relief within a strip equal in width to the depth of the place. These new methods give more accurate results and more accurately represent topography on maps.

On research vessels, gravimetric surveys are carried out using on-board gravimeters, and magnetic anomalies are surveyed. These data make it possible to judge the structure of the earth's crust under the ocean. The main research method is seismic sounding. A small explosive charge is placed in the water column and an explosion is made. A special receiver registers the arrival time of the reflected signals. Calculations determine the propagation velocity of longitudinal waves caused by an explosion in the thickness of the earth's crust. The characteristic velocity values ​​make it possible to divide the lithosphere into several layers of different composition.

Currently, pneumatic devices or an electric discharge are used as a source. In the first case, a small volume of air compressed in a special device with a pressure of 250-300 atm is released (almost instantly) in the water. At a shallow depth, the air bubble expands sharply and this imitates an explosion. The frequent repetition of such explosions, caused by a device called an air gun, gives a continuous profile of seismic sounding and, therefore, a fairly detailed profile of the structure of the earth's crust throughout the tack.

A profilograph with an electric spark gap (sparker) is used in a similar way. In this version of seismic equipment, the power of the discharge that excites the oscillations is usually small, and a sparker is used to study the power and distribution of unconsolidated layers of bottom sediments.

To study the composition of bottom sediments and obtain their samples, various systems of soil pipes and bottom grabs are used. Ground pipes have, depending on the task of the study, a different diameter, they usually carry a heavy load for maximum penetration into the ground, sometimes they have a piston inside and carry one or another contactor (core breaker) at the lower end. The tube is immersed in water and sediment at the bottom to a certain depth (but usually not more than 12-15 m), and the core extracted in this way, usually called a column, rises to the deck of the ship.

Grab grabs, which are clamshell-type devices, seem to cut out a small monolith of the surface layer of the bottom soil, which is delivered to the deck of the vessel. Self-floating bottom grab models have been developed. They make it possible to do without a cable and a deck winch and greatly simplify the method of obtaining a sample. In the coastal regions of the ocean at shallow depths, vibropiston soil tubes are used. With their help, it is possible to obtain columns up to 5 m long on sandy soils.

Obviously, all of the listed devices cannot be used to obtain samples (cores) of bottom rocks that are compacted and have a thickness of tens and hundreds of meters. These samples are obtained using conventional ship-mounted drilling rigs. For relatively small depths of the shelf (up to 150-200 m), special vessels are used that carry a drilling rig and are installed at the drilling point on several anchors. Keeping the vessel at the point is carried out by adjusting the tension of the chains going to each of the four anchors.

At depths of thousands of meters in the open ocean, anchoring a ship is technically unfeasible. Therefore, a special method of dynamic positioning has been developed.

The drilling ship goes to a given point, and the accuracy of determining the location is provided by a special navigation device that receives signals from artificial earth satellites. Then a rather complex device such as an acoustic beacon is installed on the bottom. The signals from this beacon are received by the system installed on the vessel. After receiving the signal, special electronic devices determine the displacement of the vessel and instantly issue a command to the thrusters. The desired group of propellers is turned on and the position of the vessel is restored. On the deck of the deep drilling vessel, there is a drilling rig with a rotary drilling rig, a large set of pipes and a special device for lifting and screwing pipes.

Drilling vessel "Glomar Challenger" (so far the only one) carries out work on the international project of deep sea drilling in the open ocean. More than 600 wells have already been drilled, and the maximum depth of well drilling was 1300 m. Materials of deep-water drilling have yielded so many new and unexpected facts that interest in their study is extraordinary. In the study of the ocean floor, many different techniques and methods are used, and new methods using new measurement principles can be expected in the near future.

In conclusion, a brief mention should be made of one task in the overall program of ocean research, the study of pollution. The sources of ocean pollution are varied. Discharge of industrial and domestic effluents from coastal enterprises and cities. The composition of pollutants here is extremely diverse: from nuclear industry waste to modern synthetic detergents. Significant pollution is created by discharges from ocean-going ships, and sometimes by catastrophic oil spills during accidents with tankers and offshore oil wells. There is another way to pollute the ocean - through the atmosphere. Air currents carry over vast distances, for example, lead that enters the atmosphere with the exhaust gases of internal combustion engines. In the process of gas exchange with the atmosphere, lead enters the water and is found, for example, in Antarctic waters.

Pollution definitions are now organized into a dedicated international observing system. At the same time, systematic observations of the content of pollutants in the water are assigned to the relevant vessels.

The greatest distribution in the ocean is oil pollution. To control it, not only chemical methods of determination are used, but mostly optical methods. Airplanes and helicopters are equipped with special optical devices that determine the boundaries of the area covered with an oil film, and even the thickness of the film.

The nature of the World Ocean, this, figuratively speaking, a huge ecological system of our planet, has not yet been sufficiently studied. Evidence for this assessment is provided by recent discoveries in various areas of oceanology. Methods for studying the World Ocean are quite diverse. Undoubtedly, in the future, as new methods of research are found and applied, science will be enriched with new discoveries.

The ocean for ancient man was a hostile element. The peoples who inhabited the coasts of the seas and oceans were engaged only in collecting seafood thrown ashore: edible algae, mollusks, and fish. Centuries passed, and the ocean expanse opened up to humanity more and more. Navigators of ancient times - the Phoenicians and Egyptians, the inhabitants of the islands of Crete and Rhodes, the ancient peoples who inhabited the shores of the Indian and Pacific Oceans - at that time had a good idea of ​​the prevailing winds, sea currents and storm phenomena, skillfully using them for navigation. The Phoenicians were the first navigators of antiquity (3000 BC), information about which has come down to the present. At first they swam along the coast, not losing sight of the land. Even then, the Phoenicians, who lived on the eastern coast of the Mediterranean Sea, extended their possessions far to the west. They knew about the Red Sea, the Persian Gulf, the shores of Africa, they went to the open sea without a compass, guided by the stars. Rafts could be a means for distant voyages, and then, according to the famous Norwegian scientist Thor Heyerdahl, reed boats. In Mesopotamia and ancient India, reed boats were built of quite impressive size. The centers of such shipbuilding were, apparently, only in South America, Africa and India. A few decades ago, in India, north of Bombay, the ruins of the seaport of Lothal were found. In its eastern part, a huge shipyard lined with bricks (with an area of ​​218 30 m2) was dug up. Such structures have not been found either in Hellas or in Phoenicia, this port is about four and a half thousand years old. An even more ancient port has been discovered on the island of Bahrain. Such discoveries made it possible for scientists to put forward the assumption that the primacy of navigation with the Phoenicians can be challenged by the inhabitants of the coast of the Indian Ocean.

In ancient times, the main routes of the peoples inhabiting its shores ran through the Mediterranean Sea, many of which became famous as skillful sailors. The Greeks, who replaced the Phoenicians in domination of the sea, began to study and master the coastal regions and the nature of the sea during their voyages. During the first voyages of the Greeks to the Pillars of Hercules (Gibraltar), many Greek colonies were founded (Massilia - now Marseille, Neapolis - now Naples, etc.). The scientist and traveler Herodotus (5th century BC) already argued that the Indian and Atlantic oceans are one, and also tried to explain the essence of the tides. The ancient Greeks noticed that ships approaching the Pillars of Hercules fell into a zone of high waves with a cloudless sky and no wind. This phenomenon was frightening for the ancient Greeks, and only a few daredevils could challenge this terrible element.

The works of Strabo speak of the unity of the oceans. The great scientist of antiquity Ptolemy in his work "Geography" brought together all the geographical information of that time. He created a geographical map in a conic projection and put on it all the then known geographical points - from the Atlantic Ocean to Indochina. Ptolemy claimed the existence of an ocean to the west of the Pillars of Hercules. Aristotle, the teacher of Alexander the Great, in his well-known work "Meteorology" also summarized all the information known at that time about the ocean. In addition, he showed great interest in the depths of the sea and the propagation of sound signals in them. He told the young Alexander of Macedon about this and about the benefits that can be obtained by penetrating into the water depths. To this day, Assyrian bas-reliefs depicting people who seek to dive under water with the help of goatskin furs have survived. Ancient chronicles say that, on the advice of his teacher Aristotle, Alexander the Great spent several hours under water in a cast sphere of thick glass. After such experiments of Alexander the Great, the profession of divers appeared, which played a big role in the naval wars of that time. Information has been preserved that in ancient Rome there was a special corps of divers. To communicate with their agents in the besieged cities, the Romans sent divers, to whose arm thin lead plates with dispatches engraved were attached. Already in the Middle Ages, the art of divers was firmly forgotten. And only with the onset of the Renaissance and the great geographical discoveries, it is reborn again. The famous Leonardo da Vinci is fond of designing breathing apparatus for diving into the depths of the sea.

After the Greeks comes the time of domination of the sea by the Romans. Having defeated the inhabitants of Carthage, the Romans conquered the entire eastern Mediterranean and left a detailed description of the conquered coastal lands. The Roman philosopher Seneca supported the hypothesis according to which the Earth and the waters of the Ocean stood out from the primary Chaos. He had a correct understanding of the balance of moisture on Earth and believed that evaporation is equal to the amount of water poured into the sea by rivers and rains. This conclusion allowed him to draw a conclusion about the constancy of the salinity of the waters of the oceans.

In the early Middle Ages, Scandinavian navigators (Normans, or Vikings) made their travels, well aware of the existence of currents in the Atlantic Ocean, as evidenced by the Scandinavian sagas.

In the Middle Ages, there was a long break in the development of geographical and oceanographic knowledge. Even the old well-known truths were gradually forgotten. Thus, the idea of ​​the sphericity of the Earth was forgotten, and by the 11th century, the rather perfect maps of Ptolemy were replaced by very primitive ones. During this period, although sea voyages were made (the voyages of the Arabs to India and China, the Normans to Greenland and to the shores of Northeast America), no significant oceanographic discoveries or generalizations were made. The Arabs brought a compass from China, with the help of which great successes were achieved in navigation. Thus, the period of exploration from the ancient Phoenicians to the era of great geographical discoveries can be called the prehistory of the scientific exploration of the ocean.

Further development of research is associated with major geographical discoveries of the late 15th - early 16th century. Preparing for his voyage, X. Columbus was the first to observe the trade winds over the Atlantic and made observations on currents in the open ocean. At the end of the 15th century, B. Dias rounded the Cape of Good Hope, calling it the Cape of Storms, and established that the Atlantic and Indian oceans are interconnected. Sebastian Cabot, who discovered Labrador and Newfoundland (1497-1498) for the second time after the Normans, was the first to consciously take advantage of the Gulf Stream. At this time, the cold Labrador Current also becomes known. The first round-the-world voyage of F. Magellan (1519-1522) practically proved that the Earth is a sphere and all oceans are interconnected. At the same time, the ratio of land and ocean was determined. Expedition Vasco da Gama paved the sea route from Europe to India. Along the way, observations were made of sea currents, wave processes and wind directions.

In the XVI-XVIII centuries, numerous voyages were made to various regions of the World Ocean and information in the field of oceanology gradually accumulated. It should be noted the voyages of Vitus Bering and A.I. Chirikov (1728-1741), as a result of which (secondarily after Semyon Dezhnev, 1648) the Bering Strait was discovered and the vast expanses of the northern part of the Pacific Ocean were explored, the work of the Great Northern Expedition (1734- 1741) in the seas of the Arctic Ocean (Chelyuskin and others) and three expeditions of J. Cook (1768-1779), who explored the Pacific Ocean from Antarctica (71 S) to the Chukchi Sea in the Arctic. In all these voyages, important information was collected on the hydrology of the Pacific and Arctic oceans and their seas.

Great geographical discoveries testify that it is the ocean that determines the appearance of our planet, influencing the nature of all its parts. Since then, the ocean has been under intense scrutiny by scientists, politicians, and economists.

In the 19th century, expeditionary exploration of the oceans became even more interesting. Valuable oceanographic materials were obtained as a result of domestic and foreign circumnavigations. Among them, the voyages of I. F. Kruzenshtern and Yu. F. Lisyansky on the ships "Neva" and "Nadezhda" (1803-1806), which carried out deep oceanographic observations, determination of currents and observations above sea level, and voyages of O. E. Kotzebue on the ships "Rurik"

(1815-1818) and "Enterprise" (1823-1826). Special mention should be made of the expedition of F. F. Bellingshausen and M. P. Lazarev on the boats "Vostok" and "Mirny" to Antarctica (1819-1821), which discovered the coasts of Antarctica and made a great contribution to the study of Antarctic ice (their classification and physico- Chemical properties).

But fundamental complex and intensive scientific research of the World Ocean begins only in the second half of the 19th century, when oceanological expeditions on special ships begin to equip one after another. This was largely dictated by practical considerations.

Among the expeditions, it is necessary to note the significant work of English scientists on the Challenger corvette in 1872-1876. In three and a half years, British scientists carried out 362 deep-sea studies in three oceans. The materials collected on the Challenger were so extensive that it took 20 years to process them, and the published results of the expedition took up 50 volumes. The beginning of modern complex researches of the World Ocean is connected with this expedition.

In the same years, comprehensive studies of the depths of the ocean, the relief of its bottom and bottom sediments, the physical characteristics of the water column, bottom flora and fauna were carried out in the Pacific Ocean by the Russian naval officer K. S. Staritsky. And in 1886-1889. Russian sailors on the Vityaz corvette under the direction of S. O. Makarov carried out new research in all three oceans.

A little later, Russia showed interest in the study of the Arctic Ocean, organizing an expedition led by G. Ya. Sedov.

At the end of the 19th century in Berlin, at the International Geographical Congress, an international council for the exploration of the oceans and seas was established, whose task was to study marine fisheries in order to protect them from predatory extermination. But the council did a lot for the development of science. He published international oceanographic tables to determine the salinity of sea water, density, and the content of chlorine in it. The Council established standard horizons for observation in the seas and oceans, distributed the World Ocean into regions between countries. In addition, the council was engaged in the standardization of new research methods in the creation of scientific equipment.

At the beginning of the 20th century and before the Second World War, active research was carried out in polar latitudes and in Antarctic waters.

After the Second World War, expeditionary research of the World Ocean received a new development. The works of the Swedish round-the-world expedition aboard the Albatross are widely known; Danish expedition on the ship "Galatea"; English on "Challenger-Jere-II"; Japanese on board the Ryofu-Maru, a number of American studies on the Discovery, and studies carried out by Russian scientists on board the Vityaz II. At that time, about 300 scientific expeditions from various countries worked in the World Ocean on specially equipped ships. Many marine expeditions discovered equatorial countercurrents, clarified the boundaries and regimes of already known currents, studied the currents of the West Winds and the eastern current in Antarctic waters, discovered the deep Cromwell current in the Pacific Ocean and the Lomonosov current in the Atlantic, the Humboldt current under the Peruvian current. Numerous echo sounding measurements made it possible to obtain a general, sufficiently detailed picture of the topography of the bottom of the World Ocean. New ridges were discovered (the Lomonosov ridge crossing the Arctic Ocean), many depressions, underwater volcanoes. A new value of the maximum depth of the World Ocean, found in the Mariana Trench and equal to 11,022 m, has been determined. An intensive penetration of man into the depths of the ocean began for their direct study. In the middle of the 20th century, much attention was paid by scientists to the creation of deep-sea technology. Deep-sea submersibles are being built in France, Japan, England, Canada, Germany, Russia and a number of other countries. A significant contribution to the creation of underwater vehicles was made by the Swiss physicist Auguste Picard, who in 1953 descended to a depth of 3160 m on a bathyscaphe of his own design. Dive into the Mariana Trench with Dunn Walsh. Since then, intensive study of the sea depths began.

For deep-sea diving, it was necessary to improve the respiratory system for underwater vehicles. This discovery is associated with the name of the Swiss scientist Hans Keller. He understood that in the respiratory system it is necessary to clearly maintain the necessary pressure of oxygen, nitrogen and carbon dioxide at the same level as at normal atmospheric pressure. Scientists have calculated thousands of variants of gas systems for different depths. In the late 1960s in the former Soviet Union, the United States, a whole series of underwater vehicles for exploring the ocean depths appears: Ikhtiandr, Sadko, Chernomor, Pisis, Sprut. At the end of the century, underwater vehicles reach a depth of 6000 m (Argus, Mir, Clif). In the United States, the ship "Atlantis" appears, equipped with robots to study organic life in the deep layers. At the same time (1983-1988), deep research is being carried out from the Keldysh ship in the Indian Ocean: samples of volcanic deposits were taken from a depth of 2000-6000 m. cyclones and anticyclones. The size of these eddies are 200 km in diameter and penetrate to a depth of 1500 m. The famous "Bermuda Triangle" was chosen as a test site for this experiment.

An important contribution to the study of the World Ocean was made by the expeditions of the world-famous scientist, writer J. I. Cousteau on the ships "Calypso" and "Alsion". Over the 87 years of his life (1910-1997) he made many discoveries: he improved scuba gear, created underwater houses and diving saucers, studied organic life in the oceans. He has written more than 20 major monographs, filmed more than 70 scientific documentaries about life in the waters of the oceans. For the film "A World Without Sun" the scientist received his first "Oscar". J. I. Cousteau was the permanent director of the Oceanographic Museum in Monaco. His research showed humanity the possibility of building special underwater laboratories. Back in 1962, he was the first to conduct an experiment called "Precontinent-I". Two scuba divers in the Diogenes underwater laboratory house, installed at a depth of 25.5 m, conducted an experiment and worked in scuba gear at a depth of 25-26 m for 5 hours a day. In 1963, J.I. Cousteau conducts a second experiment - "Precontinent-II" - in the Red Sea, where two underwater houses were installed. As a result of the generalization of the valuable experience of two experiments, "Precontinent-III" appeared, carried out in 1965 in the Mediterranean Sea near Monaco (Cape Ferram). At a depth of 100 m, six scuba divers live in an underwater house for 23 days. During this experiment, the researchers dived to a depth of 140 m. After that, the Precontinent-IV experiment took place with a dive to a depth of 400 m.

In the 70-80s. XX century J. I. Cousteau was the first to raise the problem of pollution of the oceans. He makes numerous dives into the depths of the oceans.

Since the end of the 20th century, scientific research has been carried out on specially equipped ships using the latest measuring devices, telemetry tools, physical and chemical methods, quantitative analysis, cybernetic methods of information processing using computers.

Modern studies of the World Ocean are distinguished by the international coordination of the results of research, which flow to the International Oceanological Committee (IOC). Now, according to the UN, there are more than 500 ships in the scientific navy of all countries of the world.

Nowadays, almost everything is open and mapped. But only almost. The meaning of the term “geographical discovery” has changed in many ways. Geographical science at the present stage sets the task of identifying relationships in nature, establishing geographical laws and patterns.

One of the most important and at the same time complex problems of modern mankind is the integrated development of the World Ocean. It can be solved only by developing a clear strategy and defining the forms of international cooperation in the development of the ocean and its preservation as an integral ecological system.

At the present stage of the development of science, great importance is attached to the study of the World Ocean by especially highly developed countries. The United States, Japan, Germany, and France stand out for the active development of national oceanographic programs.

The United States is the leader in the exploration and development of the World Ocean. Thus, in 1991, a comprehensive program was prepared in the United States COPS aimed at:

creation within a decade of the first generation of operating systems for forecasting processes occurring in the coastal regions of the ocean (ecological, biological, transport of bottom sediments);

modeling, reconstruction and forecast of synoptic variability of coastal circulation;

creation of electronic sensors, acoustic, optical, radar satellite systems for remote sensing of the ocean, autonomous in situ observation systems, numerical models of ocean circulation, methods for increasing data banks, supercomputers and data bank management systems.

Scripps Institution of Oceanography continues development and implementation of the project ATOK, for the implementation of which the Office for Advanced Ocean Research in 1994 allocated $ 56 million. Within 30 months, engineering developments and studies were carried out in the Pacific Ocean to determine the average values ​​​​of water temperatures at great depths of the ocean along paths several thousand miles long and mapping these values ​​for climate monitoring.

From February 13, 1995 to January 15, 1996, an 11-month round-the-world expedition of the largest oceanographic vessel equipped with modern equipment took place "Malcolm Baldrige" US National Oceanic and Atmospheric Administration. The expedition carried out comprehensive studies in order to obtain data banks on the interaction of the oceans and the atmosphere. The participation of the vessel in international programs was planned.

One of the last major projects of great importance for the development of physical oceanography in the USSR was the project “Pompom-70”, and in 1985 its part, which was called "Mesopolygon". As a result, seven R/Vs explored a wide range of natural processes in the tropical Atlantic and the Pacific Ocean. It is thanks to this project that the so-called polygon method of research has become widespread in the world. Its essence lies in the fact that ships or autonomous buoy stations are located on a relatively large area of ​​the ocean, from which long-term synchronous observations are made of the state of the ocean (on the surface and at different depths), as well as the atmosphere.

A comprehensive independent study of the World Ocean is beyond the power of any country. Therefore, close cooperation between scientists and specialists from different countries is practiced.

To date, the main research international programs are: a joint project to study global flows in the ocean (JGOFS), its biochemical part (BOFS); World Ocean Circulation Experiment (WOCE); technological project for the development of autonomous research underwater vehicles (AUTOSUB); global ocean observing system (GOOS); the UNESCO International Coastal Ecosystems Project (COMAR); non-living resource research program (OSNLR) and some others.

Of particular interest is the program WOCE(6 years of preparatory work, USA). The experiment, which began in 1990, is managed by a specially organized committee? The most extensive hydrological part of the program, designed for 7-10 years, involves global observations of the circulation of the World Ocean (in the first three years - the Pacific, then the Indian and Atlantic oceans).

Observations include:

Installation of moored current meters;

Study of deep-water circulation using floats of neutral buoyancy of the new type ALACE (on average at a depth of 1500 m);

Global measurements of sea surface temperature, circulation in the upper layer, atmospheric pressure using 530 drifters in a water area of ​​600 km 2 ;

Sea level measurements (direct and remote);

Use of microwave altimetry with satellites ERS-1, TOPEX/POSEIDON, ADEOS.

The modeling section of the program assumes, as a first step, the development of the eddy-resolving circulation of the North Atlantic. Special data analysis centers are being organized.

In particular, within the framework of the WOCE program in 1991, a joint Soviet-American expedition was carried out in the eastern part of the Black Sea. Six drifters, the design of which met the requirements of WOCE, were built by the MHI of the Ukrainian SSR Academy of Sciences and the Manvil-Okean firm of the Manvil joint Soviet-Swiss enterprise.

The TOPEX/POSEIDON satellite system, whose mission is to study the World Ocean, is of great importance for the WOCE program. The equipment was developed jointly by American and French scientists. The launch took place on August 10, 1992; continuous observations began from the end of September 1992. The resulting data is analyzed by a team of 200 scientists involved in the study of global ocean circulation, geodesy, geodynamics, oceanic wind and waves. A very promising method of studying the ocean is associated with the use of space facilities - orbital stations and satellites. It is possible that only it will make it possible to obtain a sufficient amount of information about the state of the ocean, equal to the amount of data on the state of the atmosphere.