From 35 million years ago to the present time, a basin was formed. The Black Sea is an internal sea of ​​the Atlantic Ocean. The Bosphorus Strait connects with the Sea of ​​Marmara, then, through the Dardanelles, with the Aegean and Mediterranean Seas. The Kerch Strait connects with the Sea of ​​Azov. From the north it cuts deep into the sea Crimean peninsula. The water border between Europe and Asia Minor runs along the surface of the Black Sea.

Length 1150 km

Width 580 km

Area 422,000 km²

Volume 547,000 km³

Coastline length 3400 km³

Greatest depth 2210 m

Average depth 1240 m

The catchment area is more than 2 million km²

Black Sea Map

Black Sea salinity map

The salty taste of sea water is given by sodium chloride, and the bitter taste is given by magnesium chloride and magnesium sulfate. Water contains 60 different elements. But it is assumed that it contains all the elements found on Earth. Sea water has a number of healing properties. Water salinity is about 18%.

Rivers flowing into the Black Sea

Due to the excess inflow of fresh water from the rivers Agoy, Ashe, Bzugu, Bzyp, Veleka, Vulan, Gumista, Dnieper, Dniester, Danube, Yeshilyrmak, Inguri, Kamchia, Kodor, Kyzylyrmak,

Kyalasur, Psou, Reprua, Rioni, Sakarya, Sochi, Khobi, Chorokhi, Southern Bug.

(more than 300 rivers) above evaporation it has less salinity than the Mediterranean Sea.

Rivers contribute 346 cubic meters to the sea. km of fresh water and 340 cubic meters. km of salt water flows from the Black Sea through the Bosphorus.

Current of the Black Sea

International experts claim that the natural cyclonic circulation of water in the Black Sea - the so-called “Knipovich glasses” - cleans the sea naturally.

Of particular interest is the issue of Black Sea currents. In the Black Sea there is a main closed ring of current from 20 to 50 miles wide, running 2-5 miles from the coast counterclockwise, and several connecting jets between its individual parts. average speed current in this ring is 0.5-1.2 knots, but with strong and stormy winds it can reach 2-3 knots. In spring and early summer, when rivers bring to the sea a large number of water, the flow intensifies and becomes more stable.

The current in question originates at the mouths big rivers and in the Kerch Strait. River waters, flowing into the sea, go to the right. Then the direction is formed under the influence of wind, shore configuration, bottom topography and other factors. From the Kerch Strait the current runs along the Crimean shores. At the southern end there is a division. The main current goes north to the mouth of the Dnieper-Bug estuary, and part of it goes to the Danube shores. Having received the Dnieper and then the Dniester waters, the main current goes to the Danube and then to the Bosphorus. Strengthened by the Danube waters and the Crimean branch, it gains its greatest strength here. From the Bosphorus, the main branch of the current, having given part of the water to the Sea of ​​Marmara, turns towards Anatolia. Prevailing winds here favor an easterly direction. At Cape Kerempe, one branch of the current deviates north to the Crimea, and the other goes further to the east, absorbing the flow of the rivers of Asia Minor. At the Caucasian coast the current turns to the northwest. Near the Kerch Strait it merges with the Azov Current. And off the southeastern coast of Crimea, division is occurring again. One branch descends to the south, diverges from the current coming from Cape Kerempe, and in the Sinop area connects with the Anatolian current, closing the Eastern Black Sea circle. And the other branch of the current from the southeastern coast of Crimea goes to its southern tip. Here the Anatolian current flows into it from Cape Kerempe, which closes the Western Black Sea circle.

Underwater river in the Black Sea

An underwater river in the Black Sea is a bottom flow of highly salty water from the Sea of ​​Marmara through the Bosphorus and along the seabed of the Black Sea. The trench through which the river flows is about 35 m deep, 1 km wide and about 60 km long. The water flow speed reaches 6.5 km/h, that is, 22 thousand m³ of water passes through the canal every second. If this river flowed on the surface, it would be sixth in the list of rivers in terms of fullness. The underwater river has elements characteristic of surface rivers, such as banks, floodplains, rapids and waterfalls. Interestingly, the whirlpools in this underwater river swirl not counterclockwise (as in ordinary rivers of the Northern Hemisphere due to the Coriolis force), but along it.

The channels at the bottom of the Black Sea were presumably formed 6 thousand years ago, when the sea level was approaching its current position. Water Mediterranean Sea broke through into the Black Sea and formed a network of trenches that are still active today.

The water in the river has a higher salinity and concentration of sediments than the surrounding water, so it flows under gravity and possibly supplies nutrients to abyssal plains that would otherwise be lifeless.

The river was discovered by scientists from the University of Leeds on August 1, 2010, and is the first such river to be discovered. Based on sonar sounding, it was previously known about the existence of channels on the ocean floor, and one of the largest such channels stretches from the mouth of the Amazon to Atlantic Ocean. The assumption that these channels could be rivers was confirmed only with the discovery of an underwater river in. The strength and unpredictability of such flows makes it impossible to study them directly, so scientists used autonomous underwater vehicles.

Sea water transparency

The transparency of sea water, that is, the ability to transmit light rays, depends on the size and quantity of suspended particles of various origins in the water, which significantly change the depth of penetration of light rays. There is a distinction between absolute and relative transparency of sea water.

Relative transparency refers to the depth (measured in meters) at which a white disk with a diameter of 30 cm disappears. Absolute transparency refers to the depth (measured in meters) to which any ray of light from the solar spectrum can penetrate. It is believed that in clear sea waters this depth is approximately 1000 to 1700 m.

Table of relative transparency of the waters of the World Ocean

Atlantic Ocean, Sargasso Sea to 66

Atlantic Ocean, equatorial zone 40 - 50

Indian Ocean, trade wind zone 40 - 50

Pacific Ocean, trade wind zone up to 45

Barents Sea, southwestern part to 45

Mediterranean Sea, off the African coast 40 - 45

Aegean Sea up to 50

Adriatic Sea about 30 - 40

Black Sea about 30

Baltic Sea, near the island of Bornholm 11 - 13

North Sea, English Channel 6.5 - 11

Caspian Sea, South part 11-13

Results of expeditions on the research vessel “Professor Vodyanitsky” (2002-2006)

If the methane outlet is deep enough underwater, the gas becomes bound in the composition " warm ice" But sometimes the thickness of gas hydrates is broken through by free, very powerful gas emissions.

Sometimes such a “methane fountain” flows for days, months... or even begins to “work” periodically, then dying down, then breaking through to the surface of the sea again. Such phenomena are called mud volcanoes, because gas, rushing upward from the bottom, takes with it masses of bottom soil, stones, water...

In many places, much more modest streams of methane rise from the bottom, spreading into clouds. We call them vultures. Some of them emit gas in an even, constant stream, others pulsate, reminiscent of a smoker's puffing pipe... There are quite a lot of seeps in the Kerch-Taman region, and off the coast of the Caucasus, and off the coasts of Georgia, Bulgaria...

Methane gas plume on the Black Sea shelf emerging on the water surface

Currents in the sea can be figuratively compared to rivers without banks. In marine science, it is customary to designate the direction of currents using the “where” principle. Unlike currents, wind and wave directions are determined by the “from” principle. For example, a wind blowing from south to north will be called south, and the current created by this wind will be called north.

Map of Black Sea currents

The currents of the Black Sea are weak, their speed rarely exceeds 0.5 meters per second, their main causes are river flow and the influence of winds. Under the influence of river flow, the water should move towards the center of the sea, but under the influence of the force of the Earth's rotation, it deviates to the right (in the northern hemisphere) by 90 degrees and flows along the coast in a counterclockwise direction. The main stream of currents has a width of 40-60 kilometers and passes at a distance of 3-7 kilometers from the coast.

Separate gyres are formed in the bays, directed clockwise, their speed reaches 0.5 meters per second.
In the central part of the sea there is a calm zone, where the currents are weaker than off the coast and are not constant in direction. Some researchers identify two separate rings in the general flow. The origin of the two rings of currents is associated with the peculiarities of the outlines of the Black Sea, which contribute to the deviation of parts of the general flow to the left off the coast of Crimea and Turkey.

An interesting system of currents is observed in the Bosphorus Strait, it has great importance for the Black Sea.

These currents were first studied at the end of the last century by Admiral Makarov. S. O. Makarov was not only an outstanding naval commander, shipbuilder, and military theorist, he was also a remarkable scientist who understood how important it is to understand the environment in which the navy had to operate.

From conversations with local residents S. O. Makarov established that there are two currents in the Bosphorus: surface and deep. He tested this fact by successively lowering a load into the water to different depths. The load was secured by a cable to a buoy floating on the surface. When the load was in the surface layers, the buoy moved towards the Sea of ​​Marmara; when the load was at the bottom, the buoy was carried towards the Black Sea. Thus, it was established that the surface current, carrying desalinated water, goes to the Sea of ​​Marmara, and the deep one, carrying denser salty water, goes to the Black Sea. S. O. Makarov established that the speed of the upper current is 1.5 meters per second, the lower one is 0.75 meters per second; The depth of the current interface is 20 meters. The lower current does not go strictly under the upper one, both of them are reflected from the capes, sometimes the current jets bifurcate.

To explain the reasons for these currents, Makarov performed the following experiment. Water was poured into a glass box, divided into two parts: salted in one part, desalinated in the other. Two holes were made in the partition, one above the other. Salty water began to move through the lower hole, the desalinated one - through the upper one. S. O. Makarov was the first to explain the origin of these two layers. Upstream is a wastewater, it is formed under the influence of excess water brought by rivers to the Black Sea. The lower one, the so-called dense one, is formed as a result of the fact that the denser waters of the Sea of ​​Marmara exert greater pressure on the underlying layers than the lighter waters of the Black Sea. This causes water to move from an area of ​​higher pressure to an area of ​​lower pressure.

When measuring heights on land, the count starts from sea levels. This does not mean that sea level is exactly the same in all areas of the World Ocean. In particular, the level of the Black Sea near Odessa is 30 cm higher than that of Istanbul, for this reason water rushes from the Black Sea to the Mediterranean (via Marmara), and in the Bosphorus Strait there is a constant current carrying Black Sea water. It is known that in the atmosphere cold air moves down towards the warmer, lighter side. The water in the Bosphorus moves in exactly the same way - the heavy Mediterranean water flows below towards the Black Sea. It is interesting that Mediterranean water is warmer, but despite this, it is heavier: the density of water depends more on salinity rather than temperature. The smallest width of the Bosphorus is 730 m, and the depth in some places does not exceed 40 m, so the smallest section of the strait is only 0.03 sq. km. The two opposing currents are a bit crowded here. Foreign scientists took measurements in the Bosporus in the 40-50s of our century and stated that a constant lower current does not exist in the strait. Mediterranean water supposedly enters the Black Sea only occasionally, in small quantities. The materials used for such a “revolution in science” turned out to be clearly insufficient. The authors of the “discovery” did not pay attention to this obvious circumstance: the flow of river water into the Black Sea far exceeds evaporation from its surface. So, if the sea were not constantly salted with Mediterranean water, it would become fresh. This is typical specifically for the Black Sea, since in the Mediterranean, for example, evaporation exceeds river flow, and the dynamics of the salt balance there is different. Accurate Facts are decisive in scientific disputes, so Soviet scientists, starting in 1958, conducted many years of research, now no longer in the strait, but in the Bosphorus region of the Black Sea. The expedition work was led by hydrologists from the Institute of Biology of the Southern Seas, located in Sevastopol; Our scientific institutions, as well as Bulgarian and Romanian scientists, took part in them. Expeditions in the Bosphorus region made it possible to establish that Mediterranean water flows into the Black Sea in all seasons of the year. After leaving the strait, this heavy water goes at the bottom, to the east, forming a stream with a thickness of 2 to 8 m, after 5-6 miles it turns to the northwest, and in the area of ​​​​the continental slope it breaks up into separate streams, gradually descends to greater depths and mixed with Black Sea water. Research has shown that in the Bosphorus both currents have a speed of about 80 cm/sec. About 170 cubic meters enter the Black Sea annually. km of Mediterranean water, and about 360 cubic meters flow out. km of Black Sea water. In order to fully determine the water balance of the Black Sea, it is also necessary to take into account the exchange with the Sea of ​​Azov and the flow of river waters. precipitation and evaporation rates. Studying the water balance of the sea is reminiscent of solving a school problem about a swimming pool with pipes. Only the problem about the sea is incomparably more difficult. Nevertheless, it is already possible to quite accurately predict the changes that will occur to the sea during certain major transformations of nature. The regulation of rivers with dams, the creation of reservoirs and diversion canals leads to a decrease in river flow, since some of the water no longer reaches the sea. The scale of such transformations is enormous. If in the Black Sea salinity does not yet change very noticeably, then in the shallow Azov Sea salinity is already leading to a noticeable decrease in fish stocks. The saltier Black Sea water enters the Sea of ​​Azov through the Kerch Strait, which, like the Bosphorus, has opposing currents. Previously, the Sea of ​​Azov received about 33 cubic meters. km of Black Sea water per year and gave 51 cubic meters. km of its own, less salty water. After the regulation of the Don and Kuban, the ratio changed in favor of the Black Sea water, and the Sea of ​​Azov began to become saltier. Salinity exceeded 12‰. This led to a decrease food base gobies and other fish. The most valuable freshwater fish for fishing began to stay closer to the mouths of rivers, and immobile mollusks are destroyed by the saltier water going below. In order to improve the water balance of the Sea of ​​​​Azov, it was decided to regulate the exchange of water in the Kerch Strait. This will make it possible to control the sea level, its salinity, and create conditions for increasing the fish stocks of Azov. One of the difficulties is that with reduced river flow there is nothing to compensate for evaporation. There is no need yet to artificially change water exchange in the Bosphorus to regulate the salinity of the Black Sea. But perhaps this problem will someday have to be solved by countries interested in its fate. Near the mouths of rivers, the Black Sea water is less salty than in the central part of the sea. But in deep-sea areas, far from the coast, does the Black Sea water have the same composition throughout the entire thickness of the sea? Is the water here stagnant or is it mixing? It has long been established that in upper layers There are currents in the seas. They are caused by winds, level differences and differences in water density. Scheme of currents in the Black Sea Some currents are constant and resemble rivers, others often change speed and direction (for example, depending on the nature of the winds). In the Black Sea, one of the reasons causing currents is the difference in level between its northern and southern parts, which we have already discussed. Water from the northwestern region of the sea “flows” to the south. But the rotation of the earth causes this current to deviate to the west, and it flows along the coast counterclockwise. The width of the current is about 60 km, and the speed of water movement is 0.5 m/sec. Part of the water goes into the Bosphorus, and the rest of the mass moves further, turning north near the eastern shore of the sea. Where the current bends around the broad protrusion of the Anatolian coast, part of the stream forms a branch heading immediately to the north; a western ring current arises. The eastern half of the sea also has its own ring current, running counterclockwise. Currents in the Black Sea are often disrupted by strong winds, which move significant masses of water and can noticeably change the water level, sometimes by half a meter. When the wind blows offshore, it pushes warm surface water out to the open sea. The water level is falling. During such a driving wind, rocks covered with algae are exposed near the shore. Instead of the warm water that has gone away, cold water appears at the surface, rising from the depths. The surge wind directed from the sea to the shore drives warm surface water and increases the water level near the shore. The ebbs and flows in the Black Sea are so small that water movements under the influence of the wind almost completely obscure them. (Tides arise in the World Ocean under the influence of lunar gravity, but in inland seas the tidal wave does not reach a great height.)

Many people who swim well or stay on the water well do not understand how you can drown near the shore when you know how to swim?! Especially when you don’t know how, and therefore you don’t go deeper than waist-deep. Having heard news reports during the holiday season about tourists who “died near the shore,” they think that the victims either did not know how to swim or were intoxicated. But they are wrong. What then is the reason?

We are talking about a very dangerous, but little-known phenomenon - rip currents, which are often also called “rip currents”. Rip currents exist in all corners of the planet and in Gulf of Mexico, and on the Black Sea, and on the island of Bali. Not only ordinary people, but also first-class swimmers who do not know how to behave in this situation can not cope with these insidious rips. The most dangerous are considered to be rip currents in shallow seas with a gentle coast, which is framed by sandbanks, spits and islands (Azov sea, etc.). In these places, during low tide, sand spits prevent the return of the mass of water to the sea. The water pressure on the narrow strait connecting the sea with the estuary increases many times over. As a result, a fast flow is formed, through which water moves at a speed of 2.5-3.0 m/s.

You can read about the physics of the occurrence of “rips” yourself on your favorite Wikipedia. For technically incompetent comrades, it is enough to know that corridors with a reverse (seaward) current constantly appear in one place or another right next to the shore. There are “rips” that are stable, and they are not so dangerous, because, as a rule, all the locals know about them and tell them where not to go for a swim. But there are so-called flash rip currents that come and go; that's exactly what they represent mortal danger. In most cases, the "ripa" corridor is narrow, 2-3 meters, and it is easy to jump out of it to the right or left. Also, in most cases, the speed of the current in the “rip” is 4-5 km/h, which is also harmless. However, several times a day, “rips” up to 50 meters wide and up to 200-400 long can occur on the same beach! If you add a speed of 15 km/h to it, then if you get into such a “rip”, if you don’t know how to deal with it, you can say a prayer. What happens when a person gets into a rip? He begins to be dragged into the open ocean. If the “rip” is wide and the speed is even minimal (5 km/h), it is useless to resist, that is, swim against the current - it will still drag you to the depths. The sad thing is that people who do not know about “rips” begin to desperately resist and frantically swim towards the shore, that is, against the current of the “rips”. Of course, nothing works out for them, and after 20-30 seconds a MONSTER PANIC begins! Can you imagine if a person doesn’t know how to swim?! Here he stands, say, waist-deep in water and thinks: “It’s a thrill! I won’t go any deeper, it’s safe here!” What is it! If she gets into a “rip”, she’ll be dragged away by the ocean and won’t ask for her last name, especially if she’s a weak woman or an elderly person. It will drag you to a place where there is no bottom... But you don’t know how to swim... It’s better not to think.

What should I do? How to deal with "rips"? If you don’t know how to swim at all, there is only one recommendation: don’t go into the water alone! Never! Only with someone experienced. Of course, you need to swim where there are lifeguards and red flags. Anyone who knows how to swim must remember that the depth up to the chest is already sufficient for a serious “rip” (10 km/h or more), which can drag you into the open ocean. What to do if you are still carried away? First and most importantly - DON'T PANIC! In no case, because if you know the rules of conduct in a “rip” and don’t panic, you will get out 100 times out of 100. The second main thing is not to resist the reverse current and under no circumstances swim to the shore! It sounds, of course, frightening, but this is the only correct logic: by resisting, you will not achieve anything, you will still continue to drag, but in a minute or two you will be exhausted, exhausted, tired and guaranteed to lose your composure. Hundreds and hundreds of excellent swimmers, athletes, athletes, weightlifters and bodybuilders unknowingly drowned in “rips”. In this situation, the matter will not be yours. So, don't panic and swim to shore! What are you doing? First: you are trying to get out of the “rip” to the side. That is, you are not swimming towards the shore, but parallel to it. Right or left, it doesn't matter. If the “rip” is narrow, 2-4 meters, then you will quickly get out of it. If it is wide - up to 50 meters, then, of course, it will not work. As soon as you realize that you can’t get out, immediately stop trying and... relax! At least lie on your back, but don’t panic. Why? Because in a minute or two the oncoming current will end and leave you alone. After that, you will turn around and swim... but not immediately to the shore, but first 50-100 meters to the side in order to get around the “rip”, otherwise you will get stuck back into it. Oh, and while you're relaxingly floating with the flow, don't forget to raise your hand high, then at least a lifeguard will help you on the way back. Another one important detail, which you need to remember: “rip” will not drag you to the bottom! This is not a whirlpool or a funnel. All the “rips” in the world are dragged from the shore along the surface, but not to the depth.

Finally, the last thing: all “rips” have clear identification marks (signs). If there are no lifeguards with red flags on the beach, you can independently determine the location of the oncoming current by one of the following signs (in any combination). A visible channel of rushing water perpendicular to the shore. A coastal zone with a changed color of water (say, everything around is blue or green, and some area is white). An area of ​​foam, some kind of marine vegetation, bubbles, which is steadily moving from the shore into the open sea. A gap in the general structure of tidal waves (a continuous strip of waves, and a 5-10-meter gap in the middle). If you see any of the things described, consider yourself lucky and just don't go swimming in that place. What if you don't see any of the four signs? This means that you are out of luck, because 80 percent of dangerous spontaneously occurring “rips” (flash rips) do not manifest themselves visually. That is, professional rescuers will still be able to identify these places, but ordinary tourists are unlikely to. Until they get sucked into one of these invisible “rips.”

In the Black Sea there is Main Black Sea Current(Rim Current) - it is directed counterclockwise along the entire perimeter of the sea, forming two noticeable rings (“Knipovich glasses”, named after one of the hydrologists who described these currents). The basis of this movement of water and its direction is the acceleration imparted to water by the rotation of the Earth - the Coriolis force. True, in such a relatively small water area as the Black Sea, the direction and strength of the wind are no less important. Therefore, the Rim Current is very variable, sometimes it becomes poorly distinguishable against the background of smaller-scale currents, and sometimes its jet speed reaches 100 cm/s.

In the coastal waters of the Black Sea, eddies of opposite direction to the Rim Current are formed - anticyclonic gyres, they are especially pronounced along the Caucasian and Anatolian coasts.

Local coastal currents in the surface layer of water are usually determined by the wind; their direction can change even during the day.

A special type of local coastal current - draft– is formed on gently sloping sandy shores during strong sea waves: the water flowing onto the shore does not retreat evenly, but along channels formed in the sandy bottom. Getting caught in such a current is dangerous - despite the efforts of the swimmer, he can be carried away from the shore; to get out, you need to swim not straight to the shore, but diagonally.

Vertical currents: rise of water from depth - upwelling, most often occurs when driven away coastal surface waters from the shore strong wind from the shore; at the same time, water from the depths rises to replace the surface water driven into the sea. Since the water of the depths is colder than the surface waters heated by the sun, as a result of the surge, the water near the shore becomes colder. The surge of water off the Caucasian coast of the Black Sea, caused by a strong northeast wind (this wind is called bora here), can be so powerful that the sea level near the coast can drop by forty centimeters per day.

In the oceans, upwellings arise from the action of the Coriolis force (created by the movement of the Earth around its axis) on masses of water carried by currents in the meridional direction (from the poles to the equator) along the coasts of the continents: the Peruvian current and the Peruvian upwelling (the most powerful in the world) off the Pacific coast South America, Benguela Current and Benguela Upwelling off the east coast of South Africa .

Upwellings lift water enriched with biogenic substances into the surface, illuminated layer of the ocean (or sea). minerals(salt ions containing nitrogen, phosphorus, silicon), necessary for the growth and reproduction of phytoplankton microalgae - the basis of life in the sea. Therefore, upwelling areas are the most productive water areas - there is more plankton, fish, and everything that lives in the ocean.