Major oceans. Materials on the Internet. World Ocean - video

Despite the fact that humanity has been paying close attention to the World Ocean for many millennia, many mysteries of the ocean remain unsolved. It is believed that to date it has been studied only ten percent. It is not surprising that the most incredible stories and myths are told about it, and the tales of the legendary Atlantis at the bottom of the ocean still excite minds.

The world ocean is a continuous, but not continuous, water shell of the planet, which includes dissolved salts and minerals carried by the rivers flowing into them from the depths of our planet. The world's oceans occupy 71% earth's surface(approximately 361 million m2), and therefore the ocean area is located on 95% of the planet’s hydrosphere. The world's oceans are extremely closely connected with the land; various substances and energy (for example, heat/cold) are constantly exchanged between them, and the water cycle in nature plays an important role in this interaction.

The prototype of the modern ocean, according to the generally accepted theory, is Panthalassa, which was formed on our planet about 444 million years ago and was divided into parts about 252 million years ago, when the lithospheric plates located under the continent of Pangea gradually began to move away from each other, breaking the continent into several parts.

Interestingly, many oceanographers have still not finally decided how many oceans there really are. First, scientists identified two, then three. In the middle of the last century, it was agreed that the World Ocean consists of four parts, but at the beginning of the 21st century. The International Hydrogeographical Bureau has identified the fifth, Southern, with the presence of which this moment Not everyone agrees.

What does the hydrosphere consist of?

Thus, the oceans known to us are parts of the World Ocean located between continents and archipelagos. They constantly exchange water masses with each other, and some currents cover as many as three oceans in a row. For example, the cold current of the Western Winds, which carries its waters not far from Antarctica, obeying the winds that blow from west to east, does not encounter large areas of land on its way, and therefore completely circles the planet, connecting the waters of the Indian, Pacific and Atlantic oceans.

Oceanographers distinguish the following oceans (they are also parts of the World Ocean):

1. Quiet. The largest ocean covers an area of ​​178.68 million km2, while the average depth of the ocean reaches almost four kilometers, and the water surface has the highest average ocean temperature - plus 19.4 ° C. Interestingly, this is where the deepest point of the Earth is located - Mariana Trench, the depth of which exceeds 11 km. Here is the highest underwater mountain in the world - the Mauna Kea volcano: despite the fact that it rises 4 thousand meters above the ocean, its height from the ocean floor exceeds 10 km, being almost 2 km higher than Everest.
2. Atlantic. It has an elongated shape, stretches from north to south, its area is 91.66 million km2, the average ocean depth is 3.5 km, and the deepest point is the Puerto Rico Trench with a depth of more than 8.7 km. This is where the most powerful flows warm current world, the Gulf Stream, and also has one of the most mysterious and mysterious places planets, Bermuda Triangle.
3. Indian. The area is 76.17 million km2, and the average depth exceeds 3.7 km (its deepest point is the Java Depression with a depth of more than 7.2 km).
4. Arctic. The area is 14.75 million km2, and the average depth is about 1.2 km, with the greatest ocean depth recorded in the Greenland Sea and slightly exceeding 5.5 km. Concerning average temperature water on the surface, then it is +1°C.
5. 5. Southern (Antarctic). In the spring of 2000, it was decided to allocate a separate ocean in the Antarctic region between 35° south. w. (based on signs of water and atmospheric circulation) up to 60° south. w. (based on the shape of the bottom topography). Officially, its size is 20.327 million km2 - it is this area that must be subtracted from the above data of the three oceans, the Pacific, Atlantic and Indian. As for the average depth of the South, it is about 3.5 km, and the most deep place is the South Sandwich Trench - its depth is about 8.5 km.

Seas, bays and straits

The world's oceans near the coast are divided into seas, bays, and straits. The bay has a direct connection with them - a part of the ocean that does not flow deeply into the land, and always has common waters with it.

But the seas can be located at a distance of several thousand kilometers, surrounded on three sides by land, but one side is always open and connected to the ocean by straits, bays, and other seas. Seas and oceans are always interconnected, if this message is not there, no matter what huge size It would not be a body of water and no matter how salinity it has, it is considered a lake.

ocean floor

The bottom of the World Ocean is the surface of the lithospheric plate on which the waters of the World Ocean are located. The underwater bottom topography is extremely diverse: there are high mountain ranges, hills, deep gorges, trenches, valleys, and plateaus. At the same time, the ocean floor consists of several parts, connecting the deepest parts of the world's oceans with land.

The area separating the ocean shores from the water is called a sandbank (shelf), the relief of which is characterized by a common geological structure with the land. The length of the shelf bottom is about 150 meters, after which it begins a sharp descent to the continental slope, the depth of which is generally from 100 to 200 m, but can sometimes reach 1.5 km, as off the coast of New Zealand.

In terms of its relief and geological structure, the continental slope, whose bottom length is from three to four kilometers, is a continuation of the land. It is interesting that there are many underwater gorges and trenches on it, the average depth of which is about eight kilometers, and in places where the oceanic plate goes under the continental plate, it can exceed ten.

Between the continental slope and the bed there is a continental foot (though not everywhere: the largest ocean on Earth, the Pacific, does not have it in some areas). The continental base is characterized by hilly terrain and its length is about 3.5 km.

The ocean floor is located at a depth of 3.5 to 6 km. The bottom topography is characterized by deep gorges, mid-ocean ridges, hills and underwater plateaus. Most of the bottom topography consists of abyssal plains located at a depth of about five kilometers, where there are a huge number of active or extinct volcanoes.

The bottom relief of all the world's oceans is characterized by the fact that in its central part, at the junction of lithospheric plates, mid-ocean ridges are located. The longest underwater mountain range is the Mid-Atlantic Ridge, 20 thousand km long (it starts near the coast of Iceland and ends near Bouvet Island, which is located in the middle of Africa and Antarctica).

Since these mountains are young, constant earthquakes and volcanic eruptions are recorded in the area of ​​the ridge, and in some places, forming islands, its peaks rise above the surface of the water.

Since the mountains are quite heavy, the ocean floor sags under them, and the relief gradually begins to drop from three to six thousand meters, turning into a deep-sea basin, the bottom of which consists of basalt and sedimentary rocks.

Flora and fauna

The nature of the ocean is amazing: its waters are home to about seventy forms from all existing forms of life on our planet, and scientists are constantly discovering new species of not only small but also large sizes. The flora is represented by various types of algae, some of them are able to live only at the surface of the water, some - at quite great depths.

As for representatives of the fauna, the majority live in tropical and subtropical latitudes, and one of the most populated places is the Great Barrier Reef, located off the coast of Australia. Among the inhabitants of the ocean there are such representatives of the animal world as fish, plankton, corals, sea ​​worms, crustaceans, cetaceans, cephalopods (squids, octopuses), and many birds live on the coast.

The nature of the Arctic and Arctic oceans is the poorest - harsh climatic conditions are to blame for this.

In the cold waters of our planet, there are more than a hundred commercial fish species, and there are also mammals adapted for life in harsh conditions: seals, walruses, whales, and those living on the coast that are ideally adapted to the conditions of the South seabirds penguins.

Ecology

Scientists have calculated that the annual weight of garbage dumped into the world's oceans is three times greater than the fish catch. Ocean pollution has reached the point that a real garbage continent floats in the North Pacific Ocean, consisting of several hundred million tons of waste, most of which is plastic products. Plastic is dangerous because when exposed to sun rays falls into pieces, maintaining a polymer structure, and in shape resembling zooplankton - as a result, deceived fish and jellyfish confuse it with food, swallow it, and then die.

Ocean pollution is caused by wastewater contaminated with various impurities, as well as rivers carrying pollutants such as oil, fertilizers (including insecticides and herbicides), which negatively affect the nature of the ocean and contribute to its death. Increasing accidents of tankers carrying oil, toxic and even radioactive waste cause environmental disasters, the consequences of which take many years to eliminate.

Despite the fact that various environmental organizations are trying to correct the situation, making quite incredible efforts to do this, their successes are only local: ocean pollution continues in geometric progression, and the active growth of industry suggests that in the near future a huge amount of water will enter the ocean waters. amount of harmful substances.

World Ocean

World Ocean

Ocean
World Ocean
a layer of water that covers most of the earth's surface (four-fifths in the Southern Hemisphere and more than three-fifths in the Northern Hemisphere). Only in places Earth's crust rises above the surface of the ocean, forming continents, islands, atolls, etc. Although the World Ocean is a single whole, for the convenience of research, its individual parts are given different names: Pacific, Atlantic, Indian and Northern Arctic Ocean s.
The largest oceans are the Pacific, Atlantic and Indian. The Pacific Ocean (area approximately 178.62 million km2) has a round shape in plan and occupies almost half of the water surface of the globe. Atlantic Ocean(91.56 million km 2) has the shape of a wide letter S, with its western and eastern coasts almost parallel. Indian Ocean with an area of ​​76.17 million km2, it has the shape of a triangle.
The Arctic Ocean, with an area of ​​only 14.75 million km 2, is surrounded by land on almost all sides. Like Quiet, it has a rounded shape in plan. Some geographers identify another ocean - the Antarctic, or Southern - the body of water surrounding Antarctica.
Ocean and atmosphere. The world's oceans, whose average depth is approx. 4 km, contains 1350 million km 3 of water. The atmosphere, which envelops the entire Earth in a layer several hundred kilometers thick, with a much larger base than the World Ocean, can be considered as a “shell”. Both the ocean and the atmosphere are fluid environments in which life exists; their properties determine the habitat of organisms. Circulation flows in the atmosphere affect the general circulation of water in the oceans, and the properties of the air largely depend on the composition and temperature of the air. ocean waters. In turn, the ocean determines the basic properties of the atmosphere and is a source of energy for many processes occurring in the atmosphere. The circulation of water in the ocean is influenced by winds, the Earth's rotation, and land barriers.
Ocean and climate. It is well known that temperature regime and other climatic characteristics of the area at any latitude can change significantly in the direction from the ocean coast to the interior of the continent. Compared to land, the ocean warms more slowly in summer and cools more slowly in winter, smoothing out temperature fluctuations on the adjacent land.
The atmosphere receives from the ocean a significant part of the heat supplied to it and almost all the water vapor. The steam rises and condenses to form clouds, which are carried by winds and support life on the planet, falling as rain or snow. However, only surface waters participate in heat and moisture exchange; more than 95% of the water is located in the depths, where its temperature remains virtually unchanged.
Composition of sea water. The water in the ocean is salty. The salty taste is given by the 3.5% dissolved minerals it contains - mainly sodium and chlorine compounds - the main ingredients of table salt. The next most abundant is magnesium, followed by sulfur; All the usual metals are also present. Of the non-metallic components, calcium and silicon are especially important, since they are involved in the structure of the skeletons and shells of many marine animals. Due to the fact that the water in the ocean is constantly mixed by waves and currents, its composition is almost the same in all oceans.
Properties of sea water. The density of sea water (at a temperature of 20 ° C and a salinity of about 3.5%) is approximately 1.03, i.e. slightly higher than density fresh water(1.0). The density of water in the ocean varies with depth due to the pressure of the overlying layers, as well as depending on temperature and salinity. In the deepest parts of the ocean, waters tend to be saltier and colder. The densest masses of water in the ocean can remain at depth and maintain a low temperature for more than 1000 years.
Because the sea ​​water has low viscosity and high surface tension, it provides relatively little resistance to the movement of a ship or swimmer and quickly drains from various surfaces. The predominant blue color of sea water is associated with the scattering of sunlight by small particles suspended in the water.
Sea water is much less transparent to visible light compared to air, but more transparent than most other substances. The penetration of solar rays into the ocean to a depth of 700 m has been recorded. Radio waves penetrate into the water column only to a small depth, but sound waves can spread thousands of kilometers underwater. The speed of sound in seawater varies, averaging 1500 m per second.
The electrical conductivity of seawater is approximately 4000 times higher than that of fresh water. The high salt content prevents its use for irrigation and watering of agricultural crops. It is also not suitable for drinking.
SEA INHABITANTS
Life in the ocean is incredibly diverse, with more than 200,000 species of organisms living there. Some, such as the lobe-finned fish coelacanth, are living fossils whose ancestors flourished here more than 300 million years ago; others have appeared more recently. Most marine organisms are found in shallow waters, where they penetrate sunlight, promoting the process of photosynthesis. Areas enriched with oxygen and nutrients, such as nitrates, are favorable for life. The phenomenon known as “upwelling” is widely known. . upwelling), - the rise to the surface of deep sea waters enriched with nutrients; it is with this that the wealth of organic life along some coasts is associated. Life in the ocean ranges from microscopic single-celled algae and tiny animals to whales that are over 100 feet long and larger than any animal that has ever lived on land, including the largest dinosaurs. Oceanic biota is divided into the following main groups.
Plankton is a mass of microscopic plants and animals that are not capable of independent movement and live in the near-surface, well-lit layers of water, where they form floating “feeding grounds” for larger animals. Plankton consists of phytoplankton (including plants such as diatoms) and zooplankton (jellyfish, krill, crab larvae, etc.).
Nekton consists of organisms freely swimming in the water column, mainly predatory, and includes more than 20,000 species of fish, as well as squid, seals, sea ​​lions, whales
Benthos consists of animals and plants that live on or near the ocean floor, both in deep and shallow waters. Plants, represented by various algae (for example, brown algae), are found in shallow water where sunlight penetrates. Of the animals, sponges, crinoids (at one time considered extinct), brachiopods, etc. should be noted.
Food chains. More than 90% of the organic substances that form the basis of life in the sea are synthesized under sunlight from minerals and other components by phytoplankton, which abundantly inhabit the upper layers of the water column in the ocean. Some organisms that make up zooplankton eat these plants and, in turn, provide a source of food for larger animals that live at greater depths. Those are eaten by larger animals that live even deeper, and this pattern can be traced to the very bottom of the ocean, where the largest invertebrates, such as glass sponges, receive the nutrients they need from the remains of dead organisms - organic detritus that sinks to the bottom from the overlying water column. However, it is known that many fish and other free-moving animals have managed to adapt to extreme conditions high pressure, low temperature and constant darkness characteristic of great depths. see also marine biology.
WAVES, TIDES, CURRENTS
Like the rest of the Universe, the ocean never remains at rest. A variety of natural processes, including such catastrophic ones as underwater earthquakes or volcanic eruptions, cause the movement of ocean waters.
Waves. Regular waves are caused by wind blowing at varying speeds over the surface of the ocean. First there are ripples, then the surface of the water begins to rise and fall rhythmically. Although the water surface rises and falls, individual particles of water move along a trajectory that is almost a closed circle, experiencing virtually no horizontal displacement. As the wind increases, the waves become higher. In the open sea, the height of a wave crest can reach 30 m, and the distance between adjacent crests can be 300 m.
Approaching the shore, the waves form two types of breakers - diving and sliding. Diving breakers are characteristic of waves that originate away from the shore; they have a concave front, their crest overhangs and collapses like a waterfall. The sliding breakers do not form a concave front, and the wave decline occurs gradually. In both cases, the wave rolls onto the shore and then rolls back.
Catastrophic waves may arise as a result sudden change depth of the seabed during the formation of faults (tsunamis), during severe storms and hurricanes (storm waves) or during landslides and landslides of coastal cliffs.
Tsunamis can travel in the open ocean at speeds of up to 700–800 km/h. As the tsunami wave approaches the shore, it slows down and at the same time its height increases. As a result, a wave up to 30 m or more high (relative to the average ocean level) rolls onto the shore. Tsunamis have enormous destructive power. Although areas near seismically active areas such as Alaska, Japan, and Chile are most affected, waves from distant sources can cause significant damage. Similar waves occur during explosive volcanic eruptions or collapse of crater walls, such as the volcanic eruption on Krakatau Island in Indonesia in 1883.
Storm waves generated by hurricanes can be even more destructive ( tropical cyclones). Repeatedly similar waves hit the coast in the upper part of the Bay of Bengal; one of them in 1737 led to the death of approximately 300 thousand people. Thanks to greatly improved early warning systems, it is now possible to warn the population of coastal cities in advance of approaching hurricanes.
Catastrophic waves caused by landslides and landslides are relatively rare. They arise from the fall of large blocks of rock into deep-sea bays; in this case, a huge mass of water is displaced, which falls onto the shore. In 1796, a landslide occurred on the island of Kyushu in Japan, which had tragic consequences: the three huge waves it generated claimed the lives of approx. 15 thousand people.
Tides. Tides roll onto the ocean shores, causing the water level to rise to a height of 15 m or more. The main cause of tides on the Earth's surface is the gravity of the Moon. During every 24 hours 52 minutes there are two high tides and two low tides. Although these level fluctuations are only noticeable near the coast and in shallows, they are known to occur in the open sea. Tides cause many very strong currents in the coastal area, so sailors need to use special current tables to navigate safely. In the straits connecting the Japanese Inland Sea with the open ocean, tidal currents reach speeds of 20 km/h, and in the Seymour Narrows Strait off the coast of British Columbia (Vancouver Island) in Canada, a speed of approx. 30 km/h.
Currents in the ocean can also be created by waves. Coastal waves approaching the shore at an angle cause relatively slow alongshore currents. Where the current deviates from the shore, its speed increases sharply - a rip current is formed, which can pose a danger to swimmers. The Earth's rotation causes large ocean currents to move clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. Some currents provide the richest fishing grounds, such as the Labrador Current off the eastern coast of North America and Peruvian Current(or Humboldt) off the coast of Peru and Chile.
Turbidity currents are among the strongest currents in the ocean. They are caused by the movement of large volumes of suspended sediment; These sediments can be carried by rivers, be the result of waves in shallow water, or be formed by a landslide along an underwater slope. Ideal conditions for the emergence of such currents exist at the tops of underwater canyons located near the shore, especially at the confluence of rivers. Such currents reach speeds of 1.5 to 10 km/h and sometimes damage submarine cables. After the 1929 earthquake with its epicenter in the Great Newfoundland Bank area, many transatlantic cables connecting Northern Europe and the USA were damaged, probably due to strong turbidity currents.
SHORE AND COASTLINES
The maps clearly show the extraordinary variety of coastal contours. Examples include coasts indented by bays, with islands and winding straits (in Maine, southern Alaska and Norway); relatively simple coastlines, like most of the west coast of the United States; deeply penetrating and branching bays (for example, Chesapeake) in the mid-Atlantic coast of the United States; the prominent low-lying coast of Louisiana near the mouth of the Mississippi River. Similar examples can be given for any latitude and any geographic or climatic region.
Evolution of the coast. First of all, let's look at how sea level has changed over the past 18 thousand years. Just before this, most of the land in the high latitudes was covered with huge glaciers. As these glaciers melted, meltwater entered the ocean, causing its level to rise by about 100 m. At the same time, many river mouths were flooded - this is how estuaries were formed. Where glaciers have created valleys deepened below sea level, deep bays (fjords) with numerous rocky islands have formed, as, for example, in the coastal zone of Alaska and Norway. When advancing on low-lying coasts, the sea also flooded river valleys. On sandy coasts, as a result of wave activity, low barrier islands were formed, stretched along the coast. Such forms are found off the southern and southeastern coasts of the United States. Sometimes barrier islands form accumulative coastal overhangs (e.g., Cape Hatteras). Deltas appear at the mouths of rivers carrying large amounts of sediment. On tectonic block shores experiencing uplifts that compensated for sea level rise, straight abrasion ledges (cliffs) can form. On the island of Hawaii, as a result of volcanic activity, lava flows and lava deltas formed. In many places, coastal development proceeded in such a way that the bays formed by the flooding of river mouths continued to exist - for example, the Chesapeake Bay or the bays on the northwestern coast of the Iberian Peninsula.
IN tropical zone rising sea levels contributed to more intensive growth of corals on the outer (marine) side of the reefs, so that inside lagoons were formed, separating a barrier reef from the shore. A similar process occurred where the island sank against the backdrop of rising sea levels. Wherein barrier reefs on the outside were partially destroyed during storms, and coral fragments were piled up by storm waves above the level calm sea. Rings of reefs around the submerged volcanic islands formed atolls. Over the past 2000 years, there has been virtually no rise in sea level.
Beaches have always been highly valued by humans. They are composed mainly of sand, although there are also pebble and even small boulder beaches. Sometimes the sand is shells crushed by waves (so-called shell sand). The profile of the beach has sloping and almost horizontal parts. The angle of inclination of the coastal part depends on the sand that composes it: on beaches composed of thin sand, the frontal zone is the most flat; On coarse sand beaches, the slopes are somewhat greater, and the steepest ledge is formed by pebble and boulder beaches. The rear zone of the beach is usually above sea level, but sometimes huge storm waves flood it too.
There are several types of beaches. For the US coast, the most typical are long, relatively straight beaches bordering the outer side of barrier islands. Such beaches are characterized by along-shore hollows, where currents that are dangerous for swimmers can develop. On the outer side of the hollows there are sand bars stretched along the shore, where the destruction of waves occurs. When the waves are strong, rip currents often occur here.
Rocky shores of irregular shape usually form many small coves with small isolated areas of beaches. These coves are often protected from the sea by rocks or underwater reefs protruding above the surface of the water.
Formations created by waves are common on beaches - beach festoons, ripple marks, traces of wave splash, gullies formed by the flow of water during low tide, as well as traces left by animals.
When beaches erode during winter storms, sand moves toward the open sea or along the shore. When the weather is calmer in the summer, new masses of sand arrive on the beaches, brought by rivers or formed when coastal ledges are washed away by waves, and thus the beaches are restored. Unfortunately, this compensation mechanism is often disrupted by human intervention. The construction of dams on rivers or the construction of bank protection walls prevents the flow of material to the beaches to replace those washed away by winter storms.
In many places, sand is carried by waves along the coast, mainly in one direction (the so-called alongshore sediment flow). If coastal structures (dams, breakwaters, piers, groins, etc.) block this flow, then the beaches “upstream” (i.e., located on the side from which sediment flows) are either washed away by waves or expand behind account of sediment supply, while the beaches “downstream” are almost not recharged with new sediments.
OCEAN BOTTOM RELIEF
At the bottom of the oceans there are huge mountain ranges, deep chasms with steep walls, long ridges and deep rift valleys. In fact, the seabed is no less rugged than the land surface.
Shelf, continental slope and continental foot. The platform that borders the continents, called the continental shelf, is not as level as was once thought. Rocky outcroppings are common on the outer part of the shelf; bedrock often appears on the part of the continental slope adjacent to the shelf.
The average depth of the outer edge (edge) of the shelf, separating it from the continental slope, is approx. 130 m. Along coastlines that have been subject to glaciation, troughs (troughs) and depressions are often observed on the shelf. Thus, off the fjord coasts of Norway, Alaska, and southern Chile, deep-water areas are found near the modern coastline; deep-sea trenches exist off the coast of Maine and in the Gulf of St. Lawrence. Glacier-made troughs often stretch across the entire shelf; In some places along them there are shallows that are exceptionally rich in fish, for example the Georges Banks or the Great Newfoundland Bank.
Shelves off the coast, where there was no glaciation, have a more uniform structure, however, on them there are often sandy or even rocky ridges rising above general level. During the Ice Age, when sea levels dropped due to the fact that huge masses of water accumulated on land in the form of ice sheets, river deltas were created in many places on the current shelf. In other places on the outskirts of the continents, at the levels of the then sea level, abrasion platforms were cut into the surface. However, the results of these processes, which occurred under conditions of low sea level, were significantly transformed by tectonic movements and sedimentation in the subsequent post-glacial era.
What is most surprising is that in many places on the outer shelf one can still find sediments formed in the past, when the sea level was more than 100 m lower than today. Bones of mammoths who lived during the Ice Age, and sometimes tools of primitive man, are also found there.
Speaking about the continental slope, it is necessary to note the following features: firstly, it usually forms a clear and well-defined boundary with the shelf; secondly, it is almost always crossed by deep underwater canyons. The average slope on the continental slope is 4°, but there are also steeper, sometimes almost vertical, sections. At the lower boundary of the slope in the Atlantic and Indian Oceans there is a gently inclined surface, called the “continental foot.” Along the periphery of the Pacific Ocean, the continental foot is usually absent; it is often replaced by deep-sea trenches, where tectonic movements (faults) generate earthquakes and where most tsunamis are generated.
Underwater canyons. These canyons, cut into the seabed for 300 m or more, are usually distinguished by steep sides, narrow bottoms, and tortuosity in plan; like their counterparts on land, they receive numerous tributaries. The deepest known underwater canyon, the Grand Bahama, is cut almost 5 km deep.
Despite the similarity with the formations of the same name on land, most submarine canyons are not ancient river valleys submerged below ocean level. Turbidity currents are quite capable of both working out a valley on the ocean floor and deepening and transforming a flooded river valley or a depression along a fault line. Underwater valleys do not remain unchanged; sediment is transported along them, as evidenced by the signs of ripples on the bottom, and their depth is constantly changing.
Deep sea trenches. Much has been learned about the topography of the deep ocean floor as a result of large-scale research that began after World War II. The greatest depths are confined to the deep-sea trenches of the Pacific Ocean. The deepest point is the so-called. “Challenger Deep” is located within the Mariana Trench in the southwest Pacific Ocean. The greatest depths of the oceans are listed below, along with their names and locations:
Arctic– 5527 m in the Greenland Sea;
Atlantic– Puerto Rico Trench (off the coast of Puerto Rico) – 8742 m;
Indian– Sunda (Javan) Trench (west of the Sunda archipelago) – 7729 m;
Quiet– Mariana Trench (near the Mariana Islands) – 11,033 m; Tonga Trench (near New Zealand) – 10,882 m; Philippine Trench (near the Philippine Islands) – 10,497 m.
Mid-Atlantic Ridge. The existence of a large underwater ridge stretching from north to south across the central Atlantic Ocean has been known for a long time. Its length is almost 60 thousand km, one of its branches stretches into the Gulf of Aden to the Red Sea, and the other ends off the coast of the Gulf of California. The width of the ridge is hundreds of kilometers; Its most striking feature is the rift valleys, which can be traced throughout almost its entire length and are reminiscent of the East African Rift Zone.
An even more surprising discovery was that the main ridge is crossed at right angles to its axis by numerous ridges and valleys. These transverse ridges can be traced in the ocean for thousands of kilometers. At the places where they intersect with the axial ridge there are so-called. fault zones to which active tectonic movements are confined and where the centers of large earthquakes are located.
Hypothesis of continental drift by A. Wegener. Until about 1965, most geologists believed that the position and shape of continents and ocean basins remained unchanged. There was a fairly vague idea that the Earth was compressing, and this compression led to the formation of folded mountain ranges. When, in 1912, German meteorologist Alfred Wegener proposed the idea that continents move (“drift”) and that the Atlantic Ocean was formed by the widening of a crack that split an ancient supercontinent, this idea was met with disbelief, despite many facts testifying in its favor (the similarity of the outlines of the eastern and western coasts of the Atlantic Ocean; the similarity of fossil remains in Africa and South America; traces of the great glaciations of the Carboniferous and Permian periods in the range of 350–230 million years ago in areas now located near the equator).
Expansion (spreading) of the ocean floor. Gradually, Wegener's arguments were supported by the results of further research. It has been suggested that rift valleys within mid-ocean ridges originate as tension cracks, which are then filled by rising magma from the depths. Continents and adjacent areas of the oceans form huge plates moving away from underwater ridges. The frontal part of the American Plate is thrust over the Pacific Plate; the latter, in turn, moves under the continent - a process called subduction occurs. There is much other evidence in favor of this theory: for example, the location of earthquake centers, marginal deep-sea trenches, mountain ranges and volcanoes in these areas. This theory explains almost everything large forms relief of continents and ocean basins.
Magnetic anomalies. The most convincing argument in favor of the hypothesis of the spreading of the ocean floor is the alternation of stripes of direct and reverse polarity (positive and negative magnetic anomalies), traced symmetrically on both sides of the mid-ocean ridges and running parallel to their axis. The study of these anomalies made it possible to establish that ocean spreading occurs at an average speed of several centimeters per year.
Plate tectonics. Further evidence for the likelihood of this hypothesis was obtained through deep-sea drilling. If, as historical geology suggests, the expansion of the oceans began during the Jurassic period, no part of the Atlantic Ocean can be older than that time. In some places, deep-sea drilling wells penetrated Jurassic sediments (formed 190–135 million years ago), but nowhere more ancient ones were found. This circumstance can be considered significant evidence; at the same time, it leads to the paradoxical conclusion that the ocean floor is younger than the ocean itself.
OCEAN EXPLORATION
Early research. The first attempts to explore the oceans were purely geographical in nature. Travelers of the past (Columbus, Magellan, Cook, etc.) made long, tiring voyages across the seas and discovered islands and new continents. The first attempt to explore the ocean itself and its bottom was made by the British expedition on the Challenger (1872–1876). This voyage laid the foundations of modern oceanology. The echo sounding method, developed during the First World War, made it possible to compile new maps of the shelf and continental slope. Special oceanological scientific institutions that appeared in the 1920s and 1930s expanded their activities to deep-sea areas.
Modern stage. Real progress in research, however, began only after the end of World War II, when the study of the ocean took part naval forces various countries. At the same time, many oceanographic stations received support.
The leading role in these studies belonged to the USA and the USSR; on a smaller scale, similar work was carried out by Great Britain, France, Japan, West Germany and other countries. In about 20 years, it was possible to obtain a fairly complete picture of the topography of the ocean floor. On the published maps of the bottom relief, a picture of the distribution of depths emerged. Great importance They have also acquired research on the ocean floor using echo sounding, in which sound waves are reflected from the surface of bedrock buried under loose sediments. More is now known about these buried sediments than about the rocks of the continental crust.
Submersibles with a crew on board. A big step forward in ocean research was the development of deep-sea submersibles with portholes. In 1960, Jacques Piccard and Donald Walsh, on the bathyscaphe Trieste I, dived into the deepest known region of the ocean - the Challenger Deep, 320 km southwest of Guam. Jacques Cousteau's "Diving Saucer" turned out to be the most successful among devices of this type; with its help it was possible to open amazing world coral reefs and underwater canyons to a depth of 300 m. Another device, “Alvin,” descended to a depth of 3650 m (with a design diving depth of up to 4580 m) and was actively used in scientific research.
Deepwater drilling. Just as the concept of plate tectonics revolutionized geological theory, deep-sea drilling revolutionized the understanding of geological history. An advanced drilling rig can drill hundreds or even thousands of meters into igneous rocks. If it was necessary to replace the dull bit of this installation, a casing string was left in the well, which could easily be detected by a sonar mounted on a new drill pipe bit, and thus continue drilling the same well. Cores from deep-sea wells have made it possible to fill in many gaps in the geological history of our planet and, in particular, have provided much evidence for the correctness of the ocean floor spreading hypothesis.
OCEAN RESOURCES
As the planet's resources struggle to meet the needs of a growing population, the ocean becomes increasingly special meaning as a source of food, energy, minerals and water.
Ocean food resources. Tens of millions of tons of fish, shellfish and crustaceans are caught in the oceans every year. In some parts of the oceans, fishing using modern floating fish hatcheries is very intensive. Some species of whales have been almost completely exterminated. Continued intensive fishing can cause severe damage to such valuable commercial fish species as tuna, herring, cod, sea bass, sardines, and hake.
Fish farming. Vast areas of the shelf could be allocated for fish farming. In this case, you can fertilize the seabed to ensure the growth of marine plants that the fish feed on.
Mineral resources of the oceans. All minerals that are found on land are also present in sea water. The most common salts there are magnesium, sulfur, calcium, potassium, and bromine. Recently, oceanographers discovered that in many places the ocean floor is literally covered with a scattering of ferromanganese nodules with high contents of manganese, nickel and cobalt. Phosphorite nodules found in shallow waters can be used as raw materials for the production of fertilizers. Sea water also contains valuable metals such as titanium, silver and gold. Currently, only salt, magnesium and bromine are extracted from seawater in significant quantities.
Oil . A number of large deposits oil, for example, off the coast of Texas and Louisiana, in the North Sea, the Persian Gulf and off the coast of China. Exploration is underway in many other areas, for example off the coast of West Africa, off the east coast of the United States and Mexico, off the coast of Arctic Canada and Alaska, Venezuela and Brazil.
The ocean is a source of energy. The ocean is a virtually inexhaustible source of energy.
Tidal energy. It has long been known that tidal currents passing through narrow straits can be used to generate energy to the same extent as waterfalls and dams on rivers. For example, in Saint-Malo in France, a tidal hydroelectric power station has been successfully operating since 1966.
Wave energy can also be used to generate electricity.
Thermal gradient energy. Nearly three-quarters of the Earth's solar energy comes from the oceans, making the ocean an ideal giant heat sink. Energy production based on the use of the temperature difference between the surface and deep layers of the ocean could be carried out on large floating power plants. Currently, the development of such systems is in the experimental stage.
Other resources. Other resources include pearls, which are formed in the body of some mollusks; sponges; algae used as fertilizers, food products and food additives, and also in medicine as a source of iodine, sodium and potassium; deposits of guano - bird droppings mined on some atolls in the Pacific Ocean and used as fertilizer. Finally, desalination makes it possible to obtain fresh water from sea water.
OCEAN AND MAN
Scientists believe that life began in the ocean about 4 billion years ago. The special properties of water had a huge impact on human evolution and still make life on our planet possible. Man used the seas as routes of trade and communication. Sailing the seas, he made discoveries. He turned to the sea in search of food, energy, material resources and inspiration.
Oceanography and oceanology. Ocean studies are often divided into physical oceanography, chemical oceanography, marine geology and geophysics, marine meteorology, ocean biology, and engineering oceanography. Oceanographic research is carried out in most countries with access to the ocean.

World Ocean- this is the salty, watery shell of the Earth surrounding the islands and continents. The collection of all the largest bodies of water on Earth. Something we simply couldn't live without. The World Ocean includes all four oceans of our planet.

World Ocean

Most of the globe is covered by seas and oceans. , which means that the aquatic world is simply obliged to surprise us with interesting and extraordinary facts, which, by the way, it does. The world ocean is the totality of all the seas and oceans on Earth. This name comes from

• Greek Okeanos - the great river flowing around the Earth,
• English WorldOcean,
• him . Weltmeer
• French Ocean, Ocean Mondial,
• Spanish Oceano, Oceano mundial)

It is important to answer the question correctly here: how many oceans are there in the world? The French scientist de Florier introduced the term for the components of the World Ocean. This term is “the world’s oceans.” The names of these oceans are

In total, on the map you will find five oceans, which together with the seas represent a large organism with its own life and its own stories. The world's oceans directly influence a huge number of natural processes, which is why it is a close object of various studies. Thus, the nature of the currents determines the climate of the regions, and in the salt water, which at first glance is unsuitable for life, there is an entire underwater world, with its large and very small representatives. Oceans of the world rich in various minerals, in addition, they represent a source of energy and food. Residents of a large number of coastal areas are engaged in fishing, which is very often their main source of income. In this article I will answer the most popular questions about the World Ocean.

Volume of the world's oceans

The world's oceans constantly exchange with environment energy, warmth. He is inexhaustible source for humanity. How big is this source? Let's find out. An ocean is a collection of water; John Murray was the first to measure its quantity. And in 1983, Leningrad scientists Shiklomanov and Sokolov carried out their measurements. The data they published states that the volume of the world's oceans is 1.338 billion km 3 of water. Murray's measurements were corrected by only 1%.

World Ocean Map

Rising sea levels

Many scientists are concerned rising sea levels. This is due to an anomaly in the Canadian Arctic Archipelago. Lifting general temperature, leads to an increase in ice melting. Gradually, over three years, the archipelago loses its snow cover, and the volume of water increases by 60 km 3 when the temperature increases by only 1 0.

World Ocean - video

Video film “Secrets of the World Ocean” - its history and impact on our survival and on the planet.

film "Secrets" depths of the sea. The Unknown World" is a popular science film made by oceanographers about what can be seen if the World Ocean is drained.

I hope that these two videos made the same impression on you as they did on me.

Which ocean is the largest in the world

The largest ocean in the world— Quiet, occupying a third of the World. This ocean is rightfully considered one of the most beautiful, amazing and wonderful, with a unique and diverse fauna. He also holds the record for the number of islands, which amount to 10 thousand. We can talk about this ocean endlessly. It is full of secrets, riddles and mystical stories. It owes its name to the voyage of Magellan, who sailed through its waters for three months. During all this time, the captain and his crew never struggled with bad weather. This ocean includes such seas as the Yellow, Japanese, Bering, Tasman, Coral, Java, and East China. Also, very important international air and sea routes pass through the Pacific Ocean.

What is the smallest ocean in the world

The smallest ocean in the world- Arctic. Situated between North America and Eurasia, it occupied only 4% of the area of ​​the entire World Ocean. It is also ten times smaller than the largest Pacific Ocean. Despite its rather modest size, this representative of the aquatic world has a unique fauna and is rich in stories.

What is the saltiest ocean in the world

List of oceans of the world complements and the saltiest ocean in the world, which is the Atlantic. Despite the fact that it collects a large amount of fresh water, the percentage of salt here is 35.4%. The Atlantic Ocean is very interesting. In almost any place, the percentage of salt is the same. This feature is unique to him. The Indian Ocean, for example, does not fit this rule at all, since in some areas the salt saturation is several times higher than the salinity of the Atlantic Ocean.

Which ocean is the warmest in the world

The Pacific Ocean will appear several times on lists of the very best. This time he became the first, as he received the title "C" warmest ocean in the world" Although relatively this fact There have always been a lot of disputes and doubts; just think a little logically, and it will become clear that this ocean deserves the title of the warmest. Thus, the cover of ice and the proximity of oceans such as the Arctic Ocean and the Atlantic to Antarctica definitely exclude them from possible contenders for this title. Only the Indian Ocean raises doubts, because it includes the most warm seas and currents. However, it is also adjacent to Antarctica, which deprives it of the title of the warmest ocean. The coldest ocean is the Arctic Ocean. He is also the smallest.

The world's oceans and its parts: what else is worth knowing

• Scientists note that the Moon has been studied much better than the World Ocean. We know only about 3% of information about him.
• Despite the thickness of the water at the bottom, in some places there are underwater waterfalls. Currently, 7 such natural phenomena are known.
• At the bottom are placed underwater rivers- areas where methane, hydrogen sulfide, seeps through cracks and mixes with water.
• The deepest point of the World Ocean is called the Mariana Trench. The maximum depth is more than 11 km.
• Almost 2.2 million live in the depths of the waters. various types organisms.
• The whale shark is recognized as one of the largest fish on earth. Its weight reaches 21.5 tons.
• The average depth of the world's oceans is 3,984 km.
• At a depth of 1 km you can find organisms that are amazing in appearance. They often have a very scary appearance.

The most beautiful ocean in the world

It is difficult to say which is the most beautiful ocean in the world, since each part of the World Ocean has its own charms and its own unique beauty. That is why you need to visit all the oceans and determine your favorite for yourself. Well, I’ll help you a little - look at the photos of the ocean.

Oceans of the world - photos

The World Ocean is the main part of the hydrosphere, constituting 94.2% of its total area, a continuous but not continuous water shell of the Earth, surrounding continents and islands, and characterized by a common salt composition.

Continents and large archipelagos divide the world's oceans into four large parts (oceans):

• Atlantic Ocean,
• Indian Ocean,
• Pacific Ocean,
• Arctic Ocean.

Sometimes the Southern Ocean also stands out from them.

Large regions of the oceans are known as seas, bays, straits, etc. The study of the earth's oceans is called oceanology.

Origin of the World Ocean

The origin of the oceans has been the subject of debate for hundreds of years.

It is believed that in the Archean the ocean was hot. Due to the high partial pressure of carbon dioxide in the atmosphere, reaching 5 bar, its waters were saturated with carbonic acid H2CO3 and were characterized by an acidic reaction (pH ≈ 3−5). A large number of different metals were dissolved in this water, especially iron in the form of FeCl2 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.

History of the study

The first explorers of the ocean were sailors. During the Age of Discovery, the outlines of continents, oceans and islands were studied. The voyage of Ferdinand Magellan (1519-1522) and the subsequent expeditions of James Cook (1768-1780) allowed Europeans to gain an understanding of the vast expanses of water surrounding the continents of our planet, and to roughly determine the outlines of the continents. The first maps of the world were created. In the XVII and XVIII centuries the coastline was detailed and the world map became modern look. However, the depths of the ocean have been very poorly studied. In the middle of the 17th century, the Dutch geographer Bernhardus Varenius proposed using the term “World Ocean” in relation to the water spaces of the Earth.

On December 22, 1872, the sailing-steam corvette Challenger, specially equipped to participate in the first oceanographic expedition, left the English port of Portsmouth.

The modern concept of the World Ocean was compiled at the beginning of the 20th century by Russian and Soviet geographer, oceanographer and cartographer Yuliy Mikhailovich Shokalsky (1856 - 1940). He first introduced the concept of “World Ocean” into science, considering all oceans - Indian, Atlantic, Arctic, Pacific - as parts of the World Ocean.

In the second half of the 20th century, intensive study of the ocean depths began. Using the echolocation method, detailed maps of the ocean depths were compiled, and the main forms of relief of the ocean floor were discovered. These data, combined with the results of geophysical and geological research, led to the creation of the theory of plate tectonics in the late 1960s. Plate tectonics is a modern geological theory about the movement of the lithosphere. To study the structure of the oceanic crust, an international program was organized to drill the ocean floor. One of the main results of the program was the confirmation of the theory.

Research methods

• Research of the World Ocean in the 20th century was actively carried out on research vessels. They made regular voyages to certain areas of the oceans. Research on such domestic ships as Vityaz, Akademik Kurchatov, and Akademik Mstislav Keldysh made a great contribution to science. Major international scientific experiments were carried out in the ocean Polygon-70, MODE-I, POLYMODE.
• The study used deep-sea manned vehicles such as Paisis, Mir, and Trieste. In 1960, the research bathyscaphe Trieste made a record dive into the Mariana Trench. One of the most important scientific results of the dive was the discovery of highly organized life at such depths.
• At the end of the 1970s. The first specialized oceanographic satellites were launched (SEASAT in the USA, Kosmos-1076 in the USSR).
• On April 12, 2007, the Chinese satellite Haiyang-1B (Ocean 1B) was launched to study the color and temperature of the ocean.
• In 2006, NASA's Jason-2 satellite began participating in the international oceanography project Ocean Surface Topography Mission (OSTM) to study ocean circulation and sea level fluctuations.
• By July 2009, one of the largest scientific complexes to explore the World Ocean.

Scientific organizations

• AARI
• VNII Oceangeology
• Institute of Oceanology named after. P. P. Shirshov RAS
• Pacific Oceanological Institute named after. V. I. Ilyichev FEB RAS.
• California Scripps Institution of Oceanography.

Museums and aquariums

• Museum of the World Ocean
• Oceanographic Museum of Monaco
• Oceanarium in Moscow

There are only 4 oceanariums in Russia so far: the St. Petersburg Oceanarium, Aquamir in Vladivostok, the oceanarium in Sochi and the oceanarium in Moscow on Dmitrovskoye Shosse (recently opened).

Division of the World Ocean

Basic morphological characteristics of the oceans

Today, there are several views on the division of the World Ocean, taking into account hydrophysical and climatic features, characteristics of water, biological factors, etc. Already in the 18th-19th centuries, there were several such versions. Malthe-Brön, Conrad Malthe-Brön and Fleurier, Charles de Fleurier identified two oceans. The division into three parts was proposed, in particular, by Philippe Buache and Heinrich Stenffens. The Italian geographer Adriano Balbi (1782-1848) identified four regions in the World Ocean: the Atlantic Ocean, the North and South Arctic Seas and the Great Ocean, of which the modern Indian Ocean became part (this division was a consequence of the impossibility of determining the exact boundary between the Indian and Pacific oceans and the similarity of zoogeographic conditions of these regions). Today people often talk about the Indo-Pacific region - a zoogeographic zone located in the tropical sphere, which includes the tropical parts of the Indian and Pacific Oceans, as well as the Red Sea. The region's border runs along the coast of Africa to Cape Agulhas, later from the Yellow Sea to the northern shores of New Zealand, and from Southern California to the Tropic of Capricorn.

In 1953, the International Hydrogeographical Bureau developed a new division of the World Ocean: it was then that the Arctic, Atlantic, Indian and Pacific oceans were finally identified.

Geography of the oceans

General physical and geographical information:

• Average temperature: 5 °C;
• Average pressure: 20 MPa;
• Average density: 1.024 g/cm³;
• Average depth: 3730 m;
• Total weight: 1.4·1021 kg;
• Total volume: 1370 million km³;
• pH: 8.1±0.2.

The deepest point of the ocean is the Mariana Trench, located in the Pacific Ocean near the Northern Mariana Islands. Its maximum depth is 11,022 m. It was explored in 1951 by the British submarine Challenger II, in honor of which the deepest part of the depression was named Challenger Deep.

Waters of the World Ocean

The waters of the World Ocean make up the main part of the Earth's hydrosphere - the oceanosphere. Ocean waters account for more than 96% (1338 million cubic km) of the Earth's water. The volume of fresh water entering the ocean with river runoff and precipitation does not exceed 0.5 million cubic kilometers, which corresponds to a layer of water on the ocean surface about 1.25 m thick. This determines the constancy of the salt composition of ocean waters and minor changes in their density. The unity of the ocean as a water mass is ensured by its continuous movement in both horizontal and vertical directions. In the ocean, as in the atmosphere, there are no sharp natural boundaries, they are all more or less gradual. Here, a global mechanism of energy transformation and metabolism takes place, which is supported by uneven heating of surface waters and the atmosphere by solar radiation.

Bottom relief

Systematic study of the bottom of the world's oceans began with the advent of echo sounders. Most of the ocean floor is flat surfaces, the so-called abyssal plains. Their average depth is 5 km. IN central parts In all oceans there are linear rises of 1-2 km - mid-ocean ridges, which are connected into a single network. The ridges are divided by transform faults into segments that appear in the relief as low elevations perpendicular to the ridges.

On the abyssal plains there are many single mountains, some of which protrude above the surface of the water in the form of islands. Most of these mountains are extinct or active volcanoes. Under the weight of the mountain, the oceanic crust bends and the mountain slowly sinks into the water. A coral reef forms on it, which builds on the top, resulting in the formation of a ring-shaped coral island- atoll

If the continent's margin is passive, then between it and the ocean there is a shelf - the underwater part of the continent, and a continental slope, smoothly turning into an abyssal plain. In front of subduction zones, where the oceanic crust plunges beneath the continents, are deep-sea trenches - the deepest parts of the oceans.

Sea currents

Sea currents - the movement of large masses of ocean water - have a serious impact on the climate of many regions of the world.

Climate

The ocean plays a huge role in shaping the Earth's climate. Under the influence of solar radiation, water evaporates and is transported to continents, where it falls in the form of various precipitation. Ocean currents transport heated or cooled water to other latitudes and are largely responsible for the distribution of heat across the planet.

Water has a huge heat capacity, so ocean temperatures change much more slowly than air or land temperatures. Areas close to the ocean have smaller daily and seasonal temperature fluctuations.

If the factors causing currents are constant, then a constant current is formed, and if they are episodic in nature, then a short-term, random current is formed. According to the predominant direction, currents are divided into meridional, carrying their waters to the north or south, and zonal, spreading latitudinally. Currents in which the water temperature is higher than the average temperature for the same latitudes are called warm, lower ones are called cold, and currents that have the same temperature as the surrounding waters are called neutral.

The direction of currents in the World Ocean is influenced by the deflecting force caused by the rotation of the Earth - the Coriolis force. In the Northern Hemisphere, it deflects currents to the right, and in the Southern Hemisphere, to the left. The speed of currents on average does not exceed 10 m/s, and their depth extends to no more than 300 m.

Ecology, flora and fauna

The ocean is a habitat for many life forms; among them:

• cetaceans such as whales and dolphins
• cephalopods such as octopuses, squids
• crustaceans such as lobsters, shrimp, krill
• sea ​​worms
• plankton
• corals
• seaweed

A decrease in ozone concentration in the stratosphere over Antarctic waters leads to less absorption of carbon dioxide by the ocean, which threatens the calcium shells and exoskeletons of mollusks, crustaceans, etc.

Economic significance

The oceans are of enormous transport importance: huge amounts of cargo are transported by ships between the world's seaports. In terms of the cost of transporting a unit of cargo per unit of distance, sea transport is one of the cheapest, but far from the fastest. To reduce the length of sea routes, canals were built, the most important of which include Panama and Suez.

• To heat the oceans to boiling point, the energy released from the decay of 6.8 billion tons of uranium is needed.
• If you take all the ocean water (1.34 billion km3) and make a ball out of it, you will get a planet with a diameter of about 1400 km.
• The World Ocean contains approximately 37 septillion (37*1024) drops.

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The water shell surrounding continents and islands and being continuous and unified is called

The word "ocean" comes from the Greek. oceanos, which means “great river flowing around the whole earth.”

The concept of the World Ocean as a single whole was introduced by a Russian oceanologist Yu. M. Shokalsky(1856-1940) in 1917

The ocean is the keeper of water. In the Southern Hemisphere it occupies 81% of the territory, in the Northern Hemisphere - only 61%, which indicates the uneven distribution of land on our planet and is one of the main factors in shaping the nature of the Earth. The ocean influences the climate (as it is a huge battery solar heat and moisture, thanks to it sharp fluctuations in temperature are smoothed out on Earth, moisturized remote areas sushi), soils, flora and fauna; is a source of various resources.

Stand out in separate part Earth's hydrosphere - oceanosphere, which accounts for 361.3 million km 2, or 70.8% of the globe's area. The mass of ocean water is approximately 250 times more mass atmosphere.

The world's oceans are not just water, but a single natural formation in its essence.

Unity of the World Ocean how the water mass is ensured by its continuous movement in both horizontal and vertical directions; homogeneous universal composition of water, which is an ionized solution containing all chemical elements Periodic tables, etc.

All processes occurring in the World Ocean have a pronounced zonal and vertical character. Natural and vertical belts of the ocean are described in section. "Biosphere of the Earth".

The world ocean is a habitat for many forms of life, since it has fairly favorable conditions for the development of life. Almost 300 thousand species of plants and animals live here, including fish, cetaceans (whales and dolphins), cephalopods (octopuses and squids), crustaceans, sea worms, corals, etc., as well as algae. More details about the inhabitants of the World Ocean are described in section. "Biosphere of the Earth".

The oceans are of great importance for the nature of the Earth and humans. For example, the transport significance of the ocean is simply undeniable. Back in the 19th century. the importance of the World Ocean as a means of communication between continents and countries became obvious. Currently, a huge amount of cargo is transported by the world's seaports. Although sea transport is not the fastest, it is one of the cheapest.

So, the significance of the World Ocean is as follows:

• is a solar heat storage device;
• determines weather, climate;
• habitat for hundreds of thousands of species;
• these are the “lungs of the planet”;
• is a source of seafood, mineral resources;
• used as a transport route;
• it is a supplier of fresh water as a result of evaporation and transfer of moisture to land.

Natural resources of the World Ocean

The waters of the World Ocean are rich in various resources. Among them are of great value organic (biological) resources. Moreover, about 90% of the ocean's biological resources come from fisheries.

Herring ranks first in terms of production volumes in the world fishery. Salmon and especially sturgeon fish are especially rich. The fish are mainly caught in the shelf zone. The use of fish is not limited to simply eating, it is used as feed meal, technical fat, fertilizers.

St. John's wort(harvest walruses, seals, fur seals) and whaling fishing is now either limited or completely prohibited.

Fishing related to catching invertebrates And crustaceans, has become widespread in countries South-East Asia and many other coastal countries in which mollusks and echinoderms are widely used as food. Crustaceans are highly valued in the market. One of the representatives of crustaceans is krill, from which food protein and vitamins are produced.

The most important natural resource of the ocean, used for preparing food, to obtain iodine, paper, glue, etc., - seaweed.

also in Lately The artificial cultivation of living organisms in the waters of the World Ocean (aquaculture) has become widespread.

Main chemical resource The ocean is the water itself and the chemical elements dissolved in it. There are about 800 desalination plants operating around the world, resulting in the production of millions of cubic meters of fresh water annually. However, the cost of this water is very high.

Main mineral resources extracted from the bottom of the sea are oil and gas. Their production continues and is growing rapidly every year. Coal, iron ore, tin and many other minerals are also mined, but this mining has not yet been fully established.

Huge and energetic resources ocean. So, water contains promising fuel nuclear reactors— deuterium (heavy water).

In some countries of the world (France, Great Britain, Canada, China, India, Russia, etc.) tidal power plants (TPPs) operate. The first TPP in the world was built in France in 1966. It was built at the mouth of the Rane River and is called “La Rane”. It is currently the world's largest tidal power plant. Its installed capacity is 240 MW. The volume of electricity production is about 600 million kWh.

More than 100 years ago, scientists proposed the idea of ​​generating energy from the difference in water temperatures in the surface and deep layers of the ocean. After 1973, extensive practical research was launched in this direction. There are experimental installations on the Hawaiian Islands, where the temperature difference at the surface of the water and at a depth of about one kilometer is 22 °C. Another hydrothermal station was built on the western coast of Africa near the city of Abidjan (the largest city in the state of Cote d'Ivoire). Power plants using the energy of sea waves can operate on a similar principle to tidal ones. One of these power plants, albeit of small capacity, was commissioned in operation in Norway in 1985

Due to its rich chemical composition, sea water has many healing properties, and sea air is saturated with many ions. This indicates the possibility of using recreational resources ocean. Sea water brings a special effect when used together with therapeutic mud and thermal waters. Therefore, seaside resorts, such as Mediterranean resorts, resorts in California, Florida, etc., are in great demand.