Black Sea. Oceanographic research of the Black Sea Black Sea in art
IN coastal zone coarse clastics predominate bottom sediments: pebbles, gravel, sands; As they move away from the coast, they are quickly replaced by fine-grained sands and silts. In the northwestern part, shell beds and modern shell banks inhabited by mussels, oysters and other shellfish are widespread. The slope and bed of the depression are characterized by pelitic silts, the carbonate content of which increases towards the center of the sea (in places exceeding 50%); Coccolithophores play a significant role in carbonate material. In the southeastern part of the sea, at depths of up to 2000 m, deposits of silt and sand carried by turbidity currents are found.
According to character wind activity over the sea, strong waves most often develop in autumn and winter in the northwestern, northeastern and central parts of the sea. Depending on the wind speed and wave acceleration length, waves with a height of 1–3 m predominate in the sea. In open areas, maximum wave heights reach 7 m, and in very strong storms they can be higher. South part The sea is the calmest, strong waves are rarely observed here, and there are almost no waves over 3 m high.
Seasonal changes in sea level are created mainly due to intra-annual differences in river flow input. Therefore, in the warm season the level is higher, in the cold season it is lower. The magnitude of these fluctuations varies and is most significant in areas influenced by continental runoff, where it reaches 30–40 cm.
The greatest magnitude in the Black Sea is caused by surge level fluctuations associated with the influence of stable winds. They are especially often observed in autumn-winter in the western and northwestern parts of the sea, where they can exceed 1 m. In the west, strong surges are caused by easterly and northeasterly winds, and in the northwest - southeasterly ones. Strong surges in these parts of the sea occur during northwestern winds. Along the Crimean and Caucasian coasts, surges and surges rarely exceed 30–40 cm. Usually their duration is 3–5 days, but sometimes it can be longer.
In the Black Sea, seiche level fluctuations up to 10 cm in height are often observed. Seiches with periods of 2–6 hours are excited by wind, and 12-hour seiches are associated with tides. The Black Sea is characterized by irregular semidiurnal tides.
Ice formation usually begins in mid-December, with maximum ice expansion observed in February. The duration of the ice period varies greatly: from 130 days in very severe winters, to 40 days in mild ones. The ice thickness on average does not exceed 15 cm, in severe winters it reaches 50 cm.
Ice is formed annually only in a narrow coastal strip in the northwestern part of the sea. Even in severe winters it covers less than 5%, and in moderate winters - 0.5–1.5% of the sea area. In very severe winters, the fast ice along the western coast extends to Constanta, and the floating ice is carried to the Bosphorus.
Water circulation throughout the year it has a cyclonic character with cyclonic gyres in the western and eastern parts seas and the main Black Sea current encircling them along the coastal current.
The main Black Sea current and cyclonic gyres are most clearly expressed in winter and summer. In spring and autumn, water circulation becomes weaker and more complex in structure.
The general circulation of sea waters is unidirectional to a depth of about 1000 m. In deeper layers it is very weak, and in general it is difficult to talk about its nature.
An important feature of the main Black Sea current is meandering, which can lead to the formation of isolated eddies that differ in salinity temperature from the surrounding waters. The size of the eddies reaches 40–90 km. The phenomenon of vortex formation is essential for water exchange not only in the upper, but also in the deep layers of the sea.
Inertial currents with a period of 17–18 hours are widespread in the open sea. These currents influence mixing in the water column, since their speeds even in a layer of 500–1000 m can be 20–30 cm/s.
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Water temperature on the sea surface in winter it rises from –0.5 to 0°C in the coastal areas of the northwestern part to 7–8°C in the central and 9–10°C in the southeastern part of the sea. In summer, the surface layer of water warms up to 23–26°C. Only during surges can short-term significant drops in temperature occur (for example, off the southern coast of Crimea).
Salinity in the surface layer all year round, it is minimal in the northwestern part of the sea, where the main volume of river water flows. In the estuary areas, salinity increases from 0–2 to 5–10‰, and in most of the water area open sea it is equal to 17.5–18.3‰. Deep waters in the layer from 1000 m to the bottom (more than 40% of the sea volume) are characterized by great constancy of temperature (8.5–9.2°C) and salinity (22–22.4‰).
During the cold season, a vertical circulation develops in the sea, which by the end of winter covers a layer with a thickness of 30–50 m in central to 100–150 m in coastal areas. The waters cool most strongly in the northwestern part of the sea, from where they are distributed by currents at intermediate horizons throughout the sea and can reach areas farthest from the centers of cold. As a consequence of winter convection, with subsequent summer heating, a cold intermediate layer is formed in the sea. It persists throughout the year at horizons of 60–100 m and is distinguished by its temperature at the boundaries of 8°C, and in the core -6.5–7.5°C.
Convective mixing in the Black Sea cannot extend deeper than 100–150 m due to an increase in salinity (and therefore density) in deeper layers as a result of the influx of salty Marmara Sea waters there. In the upper mixed layer, salinity increases slowly, and then at 100–150 m it sharply increases from 18.5 to 21‰. This is a permanent salinity jump layer (halocline).
Starting from horizons of 150–200 m, salinity and temperature slowly increase towards the bottom due to the influence of saltier and warmer Marble Sea waters entering the deeper layers. At the exit from the Bosphorus, they have a salinity of 28–34‰ and a temperature of 13–15°C, but quickly change their characteristics when mixed with Black Sea water. In the bottom layer, a slight increase in temperature also occurs due to geothermal heat influx from the seabed.
Thus, the main components are distinguished in the vertical hydrological structure of the Black Sea waters:
– the upper homogeneous layer and the seasonal (summer) thermocline, associated mainly with the process of wind mixing and the annual cycle of heat flow through the sea surface;
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– a cold intermediate layer with a minimum temperature in depth, which in the northwest and northeast of the sea arises as a result of autumn-winter convection, and in other areas is formed mainly by the transfer of cold waters by currents;
– constant halocline - a layer of maximum increase in salinity with depth, located in the contact zone of the upper (Black Sea) and deep (Marmara Sea) water masses;
– deep layer - from 200 m to the bottom, where there are no seasonal changes in hydrological characteristics, and their spatial distribution is very uniform.
The processes occurring in these layers, their seasonal and interannual variability, determine the hydrological conditions of the Black Sea.
The Black Sea has a two-layer hydrochemical structure. Unlike other seas, only the upper well-mixed layer (0–50 m) is saturated with oxygen (7–8 ml/l). Deeper, the oxygen content begins to decrease rapidly, and already at horizons of 100–150 m it is equal to zero. Hydrogen sulfide appears at the same horizons, the amount of which increases with depth to 5.3–6.6 ml/l at a horizon of 1500 m, and then stabilizes towards the bottom. In the centers of the main cyclonic gyres, where water rises, the upper boundary of the hydrogen sulfide zone is located closer to the surface (70–100 m) than in coastal areas (100–150 m).
At the border between the oxygen and hydrogen sulfide zones there is an intermediate layer of the existence of oxygen and hydrogen sulfide, which represents the lower “limit of life” in the sea.
The spread of oxygen into the deep layers of the sea is hampered by large density gradients in the contact zone of the Black Sea and Marble Sea waters. At the same time, water exchange in the Black Sea occurs throughout the entire water column, albeit slowly.
Diverse vegetable And animal world The Black Sea is almost entirely concentrated in the upper layer 150–200 m thick, constituting 10–15% of the sea's volume. The deep water column, devoid of oxygen and containing hydrogen sulfide, is almost lifeless and inhabited only by anaerobic bacteria.
Among plants, about 350 species of unicellular phytoplanktonic algae are known (including approximately 150 species each of diatoms and peridinia) and about 280 species of benthic macrophytes (129 red, 71 brown and 77 green algae and several species of sea grasses - mainly zoster). Brown algae Cystoseira and red algae Phyllophora are especially numerous, forming huge accumulations at a depth of 20–50 m in the northwestern part of the sea (of commercial importance, reserves of more than 5 million tons). The fauna of the Black Sea is approximately three times poorer than the Mediterranean.
Among animals they predominate benthic species(around 1700). The most characteristic biocenoses are mussel and phaseolin (based on the mollusk Modiola phaseolina) silts: the first, mainly at a depth of 30-70 m, the second - 50-200 m. By origin, Mediterranean invaders predominate (more than 30% of species); a lesser role is played by relics of the Pliocene brackish-water Pontic basin and freshwater invaders living in the most desalinated areas. Endemic species are about 12%. In total, 2000 species are known: about 300 - protozoa, 650 different worms (including 190 polychaetes), 640 - crustaceans, more than 200 - mollusks, 160 - fish and about 150 - animals of other groups (including 4 species - mammals - seal and 3 species of dolphins). Due to low salinity, many groups of stenohaline marine animals are few in number (for example, echinoderms - 14 species, radiolarians - 10 or absent (cephalopods, brachiopods, etc.).
Ichthyofauna The Black Sea was formed from representatives of different origins and has about 160 species of fish. One of the groups is fish of freshwater origin: bream, crucian carp, perch, rudd, pike perch, ram and others, found mainly in the northwestern part of the sea. In desalinated areas and brackish-water estuaries there are representatives of ancient fauna that have been preserved since the existence of the ancient Ponto-Caspian basin. The most valuable of them are sturgeon, as well as several types of herring. The third group of Black Sea fish consists of immigrants from the North Atlantic - these are cold-loving sprat, whiting, spiny dogfish shark, etc. The fourth, largest group of fish - Mediterranean invaders - has over a hundred species. Many of them enter the Black Sea only in summer, and winter in the Marmara and Mediterranean Seas. These include bonito, mackerel, tuna, Atlantic horse mackerel, etc. Only 60 species of fish of Mediterranean origin that permanently live in the Black Sea can be considered Black Sea. These include: anchovy, garfish, mullet, mackerel, red mullet, mackerel, galkan, stingrays, etc. Of the 20 commercial species of Black Sea fish, only anchovy, small mackerel and sprat, as well as the katran shark, are important.
Currently, the state of the Black Sea ecosystems unfavorably. The species composition of plants and animals is depleted, and the stocks of useful species are reduced. This is primarily observed in shelf areas experiencing significant anthropogenic pressure. The greatest changes are observed in the northwestern part of the sea. A large amount of biogenic and organic substances coming here with continental runoff causes the massive development of planktonic algae (“blooming”). In areas influenced by the Danube River runoff, phytoplankton biomass increased 10–20 times. When oxygen supply to the bottom layers of sea water is limited, oxygen deficiency develops - hypoxia, which can lead to the death of bottom organisms (deaths). The deterioration of water quality and oxygen conditions is one of the main reasons for the decline in the number of commercial fish in the northwestern part of the Black Sea.
There are no explored oil and gas fields in the Russian sector of the Black Sea. Only promising areas are available. On the shelf adjacent to the southern part Taman Peninsula, within the depths of the seabed of 100–200 m, local uplifts have been identified, which are the western continuation of the folds of the Kergen-Taman trough, to which the oil and gas fields of the Krasnodar Territory are confined.
On a small estuary - Lake Solenoye - located southeast of Cape Zhelezny Rog on the coast of the Taman Peninsula, a typical beach placer was discovered, composed of fine-grained sands containing a heavy fraction (7.5–30%) in which the garnet content reaches 68%.
Of great importance water protection Black Sea. The sea is most polluted by oil and petroleum products, phenols and detergents. Particularly contaminated with oil West Side seas, where ship routes run along the lines Odessa–the mouth of the Danube River–Istanbul and Odessa–the mouth of the Danube River–Varna, as well as coastal waters. Work is being carried out to prevent the discharge of untreated industrial and domestic wastewater into the sea; the discharge of oil, petroleum products and other substances that pollute water is completely prohibited.
Mild climate, good water heating in the warm season, rich and varied vegetation, the presence historical monuments cultures on the coast contribute to active recreational and resort use of the Black Sea. Main resort areas: Southern coast of Crimea (Ukraine), Black Sea coast of the Caucasus (Russia, Georgia), Golden Sands and sunny Beach(Bulgaria), Mamaia (Romania).
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| Novorossiysk and surrounding area (satellite image) |
Since 1774, Crimea, separated from the Turkish Empire, became available for research. In 1782, V. Zuev crossed the Steppe Crimea from Perekop to the city of Karasubazar (now Belogorsk) at the northern foot Crimean mountains. WITH Mountain Crimea Zuev took a quick look, visiting only some areas; He summarized the basic information from the words of people who had “experienced there.” But he was the first to draw attention to the asymmetry of the advanced part of the Crimean Mountains (the so-called cuesta): “The layers of the main mountains correspond... to the advanced ones and rise from the north by noon, rising at an angle of 17 degrees from the horizon.” And he noted that most of the Crimean rivers originate on the northern slopes of the mountains, and the Chatyrdag massif is a watershed: to the east of it the rivers flow into the Sivash, to the west into the Black Sea.
In 1783, Crimea was included in Russia and Karl Ivanovich Gablitz was appointed vice-governor of the new Tauride province. For two years he explored the peninsula in detail and compiled its first scientific description. Gablitz correctly distinguished three orographic regions there: “flat”, mountainous and flat-hilly Kerch Peninsula with steep and high banks. He was the first to propose a three-part division of the Crimean Mountains, now generally accepted: the Northern, or External (according to the Table, “advanced”) ridges, the Middle, or Internal, and the Southern, or Main. Southern slopes steeper than the northern ones, located between the mountains open valleys. The southern ridge in the Chatyrdag region is divided into two parts by a transverse valley; in the ridge he found traces volcanic activity. K. Gablitz explored the Crimean rivers, noting their large slopes and the presence of waterfalls. He also described minerals, including Kerch iron ores.
Immediately after the annexation of Crimea, by order of Catherine II, a frigate under the command of military sailor Ivan Mikhailovich Bersenev headed to the peninsula to select a harbor near the south-west. west coast. Having inspected the bay near the village of Akhtiar in April 1783 (in ancient times the city of Chersonesus-Tavrichesky was located here, see Vol. 1, Chapter 5), I. Bersenev recommended it as a base for the ships of the future Black Sea Fleet. Soon a fortress and a port were founded on its shores, which in 1784 were named “The Majestic City” (Sevastopol) by Catherine II. In the same year, I. Bersenev, commanding four ships, described the western and southern coasts of Crimea from Cape Tarkhankut to the Kerch Strait (500 km). In 1786 and 1787 K. Gablitz published two works about Crimea, adding four maps of the south to the second European Russia. On them, the outlines of the peninsula are close to modern ones: probably K. Tablits used materials from I. Bersenev.
In 1793-1795 Crimea was visited by P. S. Pallas. He described the Southern Ridge in much more detail than K. Tables and identified the highest part of it - from Balaklava to Alushta. Highest point he considered the ridge to be Chatyrdag (1527 m; now Roman-Kosh, 1545 m). Then P.S. Pallas crossed to the Taman Peninsula and gave his first detailed description: “Taman represents a torn terrain, covered with hills and planes... Various branches of the Kuban and many bays and lowlands covered with water make Taman real island. The central [its] part... between the Kuban and Temryuk estuaries is more elevated...” P. S. Pallas described the mud hills of Taman and noted the presence of oil in some.
The work of I. Bersenev was continued by the English sailor in the British and then Russian service Joseph (Iosif Iosifovich) Billings, a participant in the third circumnavigation D. Cook. After the completion of the North-Eastern Expedition (see Chapter 17), in the summer of 1797, I. Billings carried out hydrographic work off the Taman Peninsula, off the southern and western coasts of Crimea. And in the summer of the following year, he described the northwestern coast of Crimea and the Black Sea coast of European Russia from Tarkhankut to the Dniester estuary and back - a section about 1 thousand km long, which at that time was of paramount importance for the Russian state. In 1799, I. Billings published the Atlas of the Black Sea; the maps he compiled were significantly superior to their predecessors in accuracy, as they were based on numerous astronomical points he identified.
Under various wind conditions.
This manual can be used by navigators to select the most advantageous navigation routes, in design and construction organizations, in research institutions when solving various problems that require knowledge of the regime and taking into account currents, as well as in educational practice when training specialists in the field of hydrometeorology.
The atlas data cannot be used to take into account currents when sailing by dead reckoning, as well as to assess the regime of currents in coastal areas of the sea with depths less than 200 m.
When compiling the atlas, materials from oceanographic expeditions for the period 1951-1977 were used, as well as previously published manuals and results published in last years works and articles on the regime of currents and winds of the Black Sea.
The atlas was compiled at the 453 Hydrometeorological Center (453 HMC) under the general leadership of the Head of the Hydrographic Service of the Red Banner Black Sea Fleet, Candidate of Naval Sciences Rear Admiral L. I. Mitin and the Head of the Hydrometeorological Service of the Black Sea Fleet, Captain 1st Rank Engineer O. N. Bogatko, with the participation head of the hydrometeorological detachment, captain 2nd rank engineer V.N. Stetyukhno and captain 1st rank reserve engineer |V. I. Ryndenkova|.
The development of methodological issues, management of the processing and synthesis of materials, as well as the analysis of the results obtained were carried out by senior engineers of the 453rd GMC, retired captain 1st rank
| R.I. Ivanov), N.I. Zhidkova and retired lieutenant colonel-engineer K.V. ) Doctor of Physical and Mathematical Sciences S. G. Boguslavsky.
Processing, generalization and design of materials were carried out by employees of the 453rd State Medical Center and MHI of the USSR Academy of Sciences with the participation of senior researcher at the Southern Branch of the Institute of Oceanology of the USSR Academy of Sciences V. B. Titov.
The atlas was edited and prepared for publication in the 280th Central Cartographic Order of the Red Banner of Labor production of the Navy by M. A. Kislova.
Please report all reviews, suggestions and comments on the atlas to the Main Directorate of Navigation and Oceanography of the USSR Ministry of Defense at the address: 199034, city. Leningrad, B-34.
Explanations for the atlas
Highest current speeds
Unstable wind direction and constant currents
Type No. 1, schemes No. 11 - 14
Northeast wind and wind currents
Types No. 21-27, schemes No. 21-27
East wind and wind currents
Types No. 31-35, schemes No. 31-35
Southeast wind and wind currents
Types No. 41-44, schemes No. 41-44
South and southwest winds and wind currents
Types No. 51-58, schemes No. 51-58
West wind and wind currents
Types No. 61-65, schemes No. 61-65
Northwest wind and wind currents
Types No. 71-75, schemes No. 71-75
North wind and wind currents
Types No. 81-86, schemes No. 81-86
Cyclonic wind and wind currents
Types No. 91-92, schemes No. 91-92
The study of the Black Sea began in ancient times. Already in the 4th century BC, peripluses were compiled - ancient sailing directions of the sea. Another milestone in the study of the Black Sea was in 1696, when the ship “Fortress” sailed from Azov to Constantinople. Peter I ordered cartographic work to be carried out during the voyage, a drawing of the Black Sea from Kerch to Constantinople was drawn up, and depth measurements were taken. More serious study was carried out in the 18th and 19th centuries. In 1816 F. F. Bellingshausen compiled Full description Black Sea coast, in 1817 the first map of the Black Sea was published, in 1842 - the first atlas, in 1851 - the Black Sea sailing directions.
The shores of the Black Sea are slightly indented and mainly in its northern part. The only large peninsula is Crimean. The largest bays: Yagorlytsky, Tendrovsky, Dzharylgachsky, Karkinitsky, Kalamitsky and Feodosiysky in Ukraine, Varna and Burgassky in Bulgaria, Sinopsky and Samsunsky - in southern shores sea, in Turkey. The Black Sea is unique nature, the northernmost subtropics. The flora and fauna of the sea is diverse. Most of the modern inhabitants were brought from Mediterranean Sea. The fauna is represented by 2.5 thousand species of animals. Among the small marine inhabitants are mussels, oysters, and the predator mollusk rapana. Among the fish there are sturgeon (beluga, sturgeon), various types of gobies, anchovy, red mullet, sea urchin, mackerel, haddock, horse mackerel, and herring. Among mammals, the Black Sea is represented by two species of dolphins - the common dolphin and the bottlenose dolphin, as well as the white-bellied seal.
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