Map of the Black Sea currents cold and warm currents

What is a geographical map?

A geographical map is an image of the Earth’s surface with a coordinate grid and symbols, the proportions of which directly depend on scale. A geography map is a reference point by which you can identify the location of one, the yoke of an array, an object, or the location of a person. These are indispensable assistants for geologists, tourists, pilots and the military, whose professions are directly related to travel, long-distance trips.

Types of cards

Geographical maps can be divided into 4 types:

• by territory coverage these are maps of continents, countries;
• by appointment, and these are tourist, educational, road, navigation, scientific and reference, technical, tourist maps;
• by content - thematic, general geographic, general political maps;
• in scale - small-scale, medium-scale and large-scale maps.

Each of the maps is devoted to a certain topic, the thematic one reflects islands, seas, vegetation, settlements, weather, soils, taking into account the coverage of the territory. A map can only consist of the applied countries, continents or states individually at a certain scale. Given the extent to which that other territory is reduced, the map scale happens - 1x1000,1500, which means a reduction in distance of 20,000 times. Of course, it is easy to guess that the larger the scale, the more detailed the map is drawn. Nevertheless, individual parts of the earth’s surface on the map are distorted, unlike a globe that can transmit the appearance of the surface unchanged. The earth is spherical and distortions are found, such as: area, angles, length of objects.

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

Map of the Black Sea

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 flows, water should move to the center of the sea, but under the influence of the Earth's rotation force, it deviates to the right (in the northern hemisphere) by 90 degrees and goes counterclockwise along the banks. The main stream of currents has a width of 40-60 kilometers and runs at a distance of 3-7 kilometers from the coast.

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

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

For the first time, these trends were 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 wonderful scientist who understood how important it was to know the environment in which the navy had to operate.

From conversations with local residents S.O. Makarov established that in the Bosphorus there are two currents: superficial and deep. He checked this fact by successively lowering the load into water different depths. The load was fastened with a rope with a buoy floating on the surface. When the cargo was in the surface layers, the buoy moved to the Sea of \u200b\u200bMarmara, when the cargo was at the bottom, the buoy carried to the Black Sea. Thus, it was found that the surface current carrying desalinated water goes to the Sea of \u200b\u200bMarmara, and the deep, carrying denser salt water, goes to the Black Sea. S. O. Makarov established that the speed of the upper stream 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 course does not go strictly under the upper one, both of them are reflected from the capes, sometimes the stream jets bifurcate.

To explain the reasons for these currents, Makarov did such an experiment. Water was poured into a glass box, divided into two parts: saline in one part, and desalinated in the other. Two holes were made one above the other in the partition. Salt water began to move through the bottom hole, desalinated - through the top. S.O. Makarov was the first to explain the origin of these two layers. The upper course is sewage, it is formed under the influence of excess water brought by rivers to the Black Sea. The lower, the so-called density, is formed as a result of the fact that the denser waters of the Sea of \u200b\u200bMarmara exert greater pressure on the underlying layers than the lighter waters of the Black Sea. This causes water to move from an area of \u200b\u200bgreater pressure to an area of \u200b\u200blesser.

Share with friends:
The surface currents of the Black Sea originate at the mouths large rivers and in the Kerch Strait. River waters, having entered the sea, are deflected to the right by the Coriolis force. In the future, the direction of the currents is influenced by wind and coastal configuration. In spring, when river runoff is maximum, it is the main cause of surface circulation in the sea. In autumn, when surface currents depend only on wind, the currents in the underlying layers can have a different direction.

The main amount of river water flows into the northwestern part of the sea. A coastal current arises here. Having collected the waters of the Dnieper, Southern Bug and Dniester, it reaches its true scale when it receives the Danube waters. Near the Romanian and Bulgarian coasts, this current is directed south. East of Varna, where the Crimean current flows into it, a current is formed, directed to the south, to the Bosphorus. A few miles from the coast, where the axis of the current passes, it becomes the most powerful, the salinity is the smallest. From the axis of the current to the shore, the salinity increases slightly, the speed of the current weakens, and conditions for the occurrence of a counterflow (directed to the north) appear. Directly near the coast, depending on its configuration, there are local currents. Under the influence of local river runoff, salinity here decreases. The currents adjacent to the coast are weak, they are more strongly affected by winds. In general, however, the southern current dominates. Due to the seasonal change of winds and the influx of river waters, the southern current is most intense in winter and spring. In the summer, when it weakens, the northern countercurrent is more pronounced. The latter also intensifies in the fall, sometimes even more significantly.

From the Bosphorus, the main part of the coastal course continues to move near Anatolia. The prevailing winds favor the eastern direction of the current. From Cape Kerempe, one stream deviates north to the Crimea, the other continues to move east, capturing the flow of Turkish rivers along the way.

The surface current usually forms a vortex in the southwestern part of the sea, which arises mainly under the influence of southeastern and northerly winds.

Near the coast of the Caucasus, a northwestern course prevails. In the area of \u200b\u200bthe Kerch Strait, it merges with the Azov Current. At southeast Crimean coast is divided. One branch, descending to the south, diverges from the current going from Cape Keremp, and in the Sinop area it merges into the Anatolian current. Thus, the circle of the East Black Sea cyclonic cycle closes. Another branch of the Azov current from the Crimea is directed west and is divided into currents of the north-western direction (towards Odessa) and the south-western direction (towards Varna). The latter is called the Crimean current and, when merged with the “river current” created by the waters of the Dnieper, Southern Bug, Dniester and Danube, closes the circle of the West Black Sea cyclonic cycle.

Under cyclonic surface currents at a depth of 150-200 m, compensation anticyclonic currents are often formed. Such currents exist near the mouths of large rivers. To the central regions of the sea, the current velocity decreases.

In the central regions there are practically no definitely directed currents; there is only a drift movement of water masses that occurs under the influence of wind.

With strong winds from land, the outflow of surface water from the coast and the rise of the waters of the underlying layers are sometimes observed.

With strong winds from the sea, in addition to the excitement, the surface coastal current intensifies, but only slightly during all seasons except winter. In winter, the surge effect, combined with strong cooling of coastal water, creates conditions for the formation of vertical circulation and lowering of water along the shelf to great depths.

Excitement. The intensity of the waves, the height of the waves and their speed depend on the speed of the wind, its duration and acceleration of the wave.

The maximum excitement on the Bulgarian coast, obviously, should be at east winds, and the Caucasus - with the western. With a wind force of 7-8 points, lasting two days, waves 7 meters high and about 90 meters long should form near the Bulgarian shores. In fact, even with very strong storms, the maximum waves are smaller due to the influence of coastal shallow water.

At the Caucasian coast, where there are significant depths, the waves are higher; Thus, in the Poti region, waves with a height of about 5 m were noted, and in the Sochi region during a severe storm on January 28-29, 1968 a wave with a height of 7 m was recorded with a period of 9-10 s.

On the Bulgarian coast, waves of approximately this height were observed only on January 17-18, 1977 and October 18, 1979.

In the open sea, with a 5-7-point wind, the Black Sea wave has the following average values: period 6-7 s, speed 2.4-5 m / s, length 10-30 m and height 1.5-2.5 m. rare "cases of severe storms, the wave height reaches 5-6 m," and the length of 70-80 m.

The shock force of the waves is very large. According to the record of a dynamograph installed on a wave breaker in Tuapse, with a western wind of 4-5 points and a wave with a period of 11 s, the impact force was 5.7 tons per 1 m2.

The intensity of the excitement changes / according to the seasons - is it maximum in autumn and winter, and minimum - in ma? and June.

In the mode of excitement, daily changes are also observed. In most cases, the height of the waves in the afternoon hours is greater than in the morning. This is most clearly expressed in the summer, when the breeze circulation develops - in the afternoon the wave becomes 10 cm higher than in the morning. In winter, such differences are insignificant - on average 1 cm, and even at night the waves are higher than in the afternoon.

After the toga as the wind stopped, the excitement does not immediately subside, a swell persists - gentle smoothly moving waves. If a strong wind caused a surge of water in one part of the sea and a drive-in in another, level fluctuations similar to those of a weighing pan arise. These vibrations are called seiches. Their cause may also be a sharp change in atmospheric pressure. The wave that began on the surface of the sea penetrates into the deeper layers and gradually fades with depth. At the boundaries of the layers, which differ in density, internal waves of large amplitude and length are formed. They are the cause of rapid changes in temperature, salinity and other hydrological and hydrochemical parameters of water, most often at depths of 150-200 m.

Vertical exchange

Analyzing the data on the seasonal distribution of layer stability, it can be noted that in winter, when the conditions are favorable for maximum vertical mixing, even during severe storms it is limited to the upper 100-meter layer; only occasionally, weakening, mixing can penetrate to a depth of 150-200 m. Despite strong winter cooling, the waters of the upper 200-meter layer are less dense than the waters of the underlying more saline layers. As a result, winter vertical mixing in the Black Sea develops only to a depth of 200 m. Below this horizon, vertical water exchange is difficult.

Main role in vertical water exchange between the 200-meter upper layer and the deep waters of the Black Sea, an influx of marble-sea water plays. Many authors are of the opinion that its role is not so significant, since for the year about 1/2000 of the volume of deep Black Sea waters passes through the Bosphorus from the Sea of \u200b\u200bMarmara, that is, the marble-sea inflow completely replaces deep waters in about 2000 years. However, such conclusions are made for the case when the salinity of the Marble Sea jet is about 35 and / oo. In reality, according to Bulgarian scientists, the salinity of the Lower Bosphorus stream in most cases is about 24-25 ° / oo, since in the Bosphorus and in the Bosporus area - the sea waters are intensively mixed with the Black Sea, the salinity of which is about 18 ° / oo. Therefore, less saline waters enter the deep layers of the Black Sea, but in a larger volume - not 229 km3 per year, but about 1000 km3. Thus, a complete renewal of deep water should occur in about 480 years. In fact, it will occur faster due to compensatory outflow of water, vertical mixing, under the influence of internal waves, turbulence, exothermic processes, rise and fall of water in systems of cyclonic and anticyclonic flows, and a number of other reasons.

The Black Sea is the inland sea of \u200b\u200bthe Atlantic Ocean, washed by the shores of Ukraine, Russia, Georgia, Romania, Bulgaria, Turkey.

The area is 422 thousand km2, the length between the western and eastern points is about 1167 km, between the northern and southern - 624 km. The largest peninsula is Crimean, the largest gulf (off the coast of Ukraine) is Karkinitsky, Kalamitsky, Feodosiyskaya, Dzharylgachsky. Off the coast of Ukraine, the largest island is Snake. The average depth is 1271 m, the maximum is 2245 m. The shores of the Black Sea are not very dissected, most often mountainous, steep, but they are gentle in the continental part of Ukraine.
Within Ukraine, they flow into the Black Sea large rivers: Danube, Dniester, Southern Bug, Dnieper. Many resorts: Sochi, Gelendzhik, resorts of Crimea, Abkhazia, Bulgaria.
Most of Sea is located in the subtropical zone. Winter is warm and humid. The air temperature in January over the Black Sea is -1 ... + 8 ° С, the surface water temperature is + 8 ° ... 9 ° С, except for the northwestern and northeastern parts, where the sea freezes in harsh winters. Summer is hot and dry. Air temperature +22 ... 25 ° С, surface water Н24 ... 26 ° С. The average rainfall increases from west to east from 200-600 to 2000 mm or more. The average salinity is 21.8%.
The waters of the Black Sea at depths of more than 50-100 m are saturated with hydrogen sulfide, which negatively affects its organic life.

In the Black Sea, there are more than 300 species of algae and over 180 species of fish that live mainly in the upper layer (above the hydrogen sulfide zone). Hamsa, horse mackerel, mullet, flounder, mackerel, algae and invertebrates (mussels, shrimps, oysters) are of industrial importance. Each year, the sea gives up to 300 thousand tons of biological resources. Explored industrial reserves of natural gas and oil. The therapeutic value is the mud of the Black Sea estuaries. The Black Sea has a number of bays, convenient for ships.

The Black Sea extends from west to east for 1160 km., Its greatest width is 580 km. The total area of \u200b\u200bthe water area exceeds 420 thousand km2. The sea fills a large tectonic hollow. Its maximum depth is 2245 m. The largest bays are Dzharylgach, Karkinitsky, Kalamitsky, Feodosiyskaya, Sivash, Obitichna, Berdyansk. The Danube, Dnieper, Dniester, and Southern Bug rivers flow into the Black Sea. In the areas between the rivers of the coast, water bodies are connected that communicate with the sea - estuaries. Of these, on the Black Sea coast there are estuaries Dniester, Hadzhibey, Kuyalnitsky, Tiligulsky, Dnieper, Azov coast - Ulyutsky, Dairy. The peninsula of the Black Sea is the Crimean, which connects to the mainland by the Perekop Isthmus. In the Sea of \u200b\u200bAzov, elongated land areas - spits - attract attention. The largest among them is the Arabat Spit. In the Black Sea, the largest island is Dzharylgach.

The Kerch Strait connects the Black Sea with the Sea of \u200b\u200bAzov. The depth of the strait is up to 4 m.

The climatic conditions of the Black Sea are characterized by subtropical features. Summer is dry and hot, winter is wet and warm. In winter, Mediterranean and Atlantic cyclones move over it, with which rain and fog weather are associated. In summer, the Black Sea is influenced by the Azores maximum, due to which cloudless weather prevails here, thunderstorms and tornadoes are a rare occurrence.

The sea level fluctuations associated with the tides are insignificant, their amplitude is only 10 cm. The fluctuations under the influence of wind activity reach 1.5 m. The water temperature in summer is +24, + 26 ° C, and in winter it drops to +6, +7 ° C. From a depth of 150 m. The temperature became (8 ° C). In years with harsh winters the northwestern part of the Black Sea freezes.

The salinity of the upper layer of water in the Black Sea is 17-18%. With depth, salinity rises to 22.5%. Compare these indicators with the following: the average salinity of the oceans is 35%, The Mediterranean Sea - up to 38, and the Red Sea - 40% o. Find out why the salinity of the Black Sea is much lower.

Characteristic feature natural conditions The Black Sea is the existence in it of a permanent layer of hydrogen sulfide at depths below 100-120 m. This layer is inhabited by bacteria that use hydrogen sulfide. Important is the fact that the hydrogen sulfide stratum is 87% of the total Black Sea volume. And only 13% of the Black Sea water contains oxygen, it is in this small layer that animals are found. Researchers note that hydrogen sulfide rises to the surface.

Up to 300 thousand tons are selected annually from the Black Sea. Biological resources. Construction sand, gravel, and combustible gas are also mined here; The search for oil fields on the shelf continues.

Permanent link to a file - http: // site

+ additional material:

Summer holidays on the Black Sea - many Russians dream about this during their workdays. However, the southern beaches are fraught with many dangers. Each tourist season, media reports about people who died while swimming in shallow water. main reason such accidents are bottom currents. Their locals call dragons, because these streams of water can easily drag even experienced swimmers to the other world.

What kind of rips and drafts

Great influence on the Black Sea currents is exerted by the strength and speed of the wind. Under the influence of storms and other meteorological phenomena the direction of water flows in this hydrological facility is changing rapidly.

Group of scientists: A.G. Zatsepin, V.V. Kremenetsky, S.V. Stanichny and V.M. Burdyugov, representing the P.P. Shirshova and the Sevastopol Marine Hydrophysical Institute, wrote a scientific article "Basin circulation and mesoscale dynamics of the Black Sea under wind exposure." This scientific work was published in the collection " Contemporary issues dynamics of the ocean and atmosphere ”(Moscow, 2010 edition).

The authors of the study noted that, depending on the wind, the structure and intensity of the coastal current can repeatedly change from the "jet" to the "wave-vortex" mode of water circulation. And this is confirmed by long-term observations.

The instability and variability of the Black Sea often leads to the formation in the coastal zone of the so-called draft or rip currents (rip current). As a result of the storm, waves appear on the gently sloping sandy beaches, which move not toward the shore, but rather away from it. And swimmers caught in such rips or drafts can not get to land in any way: the current nullifies all their efforts. In the end, exhausted and panicking people are drowning in shallow water, very close to the shore.

Such dangerous phenomena occur on many beaches where the gently sloping bottom is framed by sandbanks and scythes. Rips are often found in the Gulf of Mexico, by the Pacific Islands, in the resorts of India, in the Mediterranean, Black and Azov Seas, and residents of the Far East are aware of them.

Although the size of the draft is usually small, it reaches 10-15 meters in width and not more than 100 meters in length, the flow velocity is quite high - up to 3 meters per second. So the trained swimmer may not be able to cope with such a stream.

Vacationers should be careful. If some part of the sea surface located near the coast differs noticeably from the rest of the water area in color and the nature of the movement of water, and white foam has formed on its surface, then it is absolutely impossible to get into the water in this place.

How do they arise

Scientists argue about the causes of the formation of draft vehicles throughout the history of meteorological observations. Most experts believe that the matter is in the strength and speed of the wind. This point of view is supported, for example, by Natalia Balinets, a hydrologist at the Hydrometeorological Center of the Black Sea Fleet of the Russian Federation. Her article “Conditions for the occurrence of a draft in the ports of the Black Sea” was published in the specialized journal “Environmental Safety of Coastal and Offshore Zones and the Integrated Use of Shelf Resources” (No 15 for 2007).

ON THE. The Balinian called the breaking current a particularly dangerous hydrometeorological phenomenon. After analyzing the conditions for the appearance of the draft for a long-term observation period, she determined which atmospheric processes precede them. It turned out that in almost 80% of cases, such currents arise as a result of storms formed by Mediterranean cyclones that arrived in the southwestern part of the Black Sea.

But the most powerful pulling rods arise in this situation: “Above the northwestern, northern or central regions European territory Russia is the center of an extensive cyclone, its hollow covers the northern part of the Black Sea. An anticyclone or ridge extends over Turkey or the Balkans. South winds prevail over the sea. ”

As N.A. wrote Balinese, in this case, the speed of storm winds can reach a special force, and the excitement of water in some places is fixed at around five points. After such meteorological phenomena in a calm-looking water area and pull-rods appear.

Why are they dangerous

Every year, tourists die on the Black Sea. After the start of the swimming season, local authorities and EMERCOM employees regularly publish warnings in the media that swimming in certain places after severe storms is forbidden, but vacationers, as a rule, ignore such messages. People do not want to lose the long-awaited vacation days, no matter what.

This topic, for example, was dedicated to the plot of the regional television channel 360, called “Tourists in Anapa ignored the warning about the bottom current. And it is mortally dangerous ”(release date - July 1, 2019).

The authors of the television story Anastasia Kukova and Ekaterina Andronova talked with the head of the Krasnodar Regional Hydrometeorological Center Andrei Bondar. The expert said that the tourist season of 2019 is just beginning, and on the beaches of Anapa several cases have already been recorded when vacationers were carried away to the sea. And all because people do not pay attention to storm warnings and behave inadvertently.

“The wind is strong enough now. On our coast, the course is mainly western destinations, and it pumps surface water to the shore. Therefore, the bottom counterflow is enhanced. If you dive, you can be carried away quite far from the shore, and it will be very difficult to swim, ”A.N. Cooper.

How to escape from such a course

Experienced swimmers and rescuers argue that people who fall into the trap of a reverse flow should not panic. The main thing is to soberly assess the current situation.

The author of the daily informative magazine ShkolaZhizni.ru, Maxim Selinsky, wrote an article entitled “Breaking Current - the Main Danger for Bathing in the Ocean or Sea” (publication date - September 7, 2017). It says that it is panic that most often leads to the death of a swimmer who is desperately torn to the shore, losing his last strength and completely exhausting himself. People should remember that the width of an ordinary draft is only 5-10 meters, it is not able to carry a person far into the open sea: the fencing current, as a rule, completely subsides less than 100 meters from the coast.

“Do not try to fight the flow. Its speed can be such that even the Olympic swimming champion cannot cope with it. Once in the opposite direction, one should sail not directly towards the shore, but parallel to it, that is, away from the stream. In this way you can get out of the trap, after which you can sail towards the shore. Or, having realized that a bump current is blowing you, swim at an angle of 45 degrees to the coast and gradually get out to the coast, ”advises Maxim Selinsky.

And of course, caution should be exercised, do not ignore rescue warnings, closely monitor the coastal waters. If in any place the water moves in the opposite direction from the coast, then this can be noticed by the change in the color of the wave and the white foam (lamb) that appears on the surface.