The deepest point in the Black Sea. The depth of the Black Sea - useful information

The area of ​​the Black Sea is 422,000 km² (according to other sources - 436,400 km²). The outline of the Black Sea resembles an oval with the longest axis about 1150 km. The greatest length of the sea from north to south is 580 km. Greatest depth- 2210 m, average - 1240 m.

The sea washes the shores of Russia, Ukraine, Romania, Bulgaria, Turkey and Georgia. On the northeastern coast of the Black Sea there is an unrecognized public education Abkhazia.

A characteristic feature of the Black Sea is complete (with the exception of a number of anaerobic bacteria) absence of life at depths above 150-200 m due to the saturation of deep layers of water with hydrogen sulfide. The Black Sea is an important transport area, as well as one of the largest resort regions in Eurasia.

In addition, the Black Sea retains important strategic and military significance. The main military bases of the Russian Black Sea Fleet are located in Sevastopol and Novorossiysk.

The ancient Greek name of the sea is Pont Aksinsky (Greek Πόντος Ἄξενος, “Inhospitable Sea”). In Strabo's "Geography" it is assumed that the sea received this name due to difficulties with navigation, as well as the wild hostile tribes inhabiting its shores. Later, after the successful development of the shores by Greek colonists, the sea began to be called Pontus Euxine (Greek Πόντος Εὔξενος, “Hospitable Sea”). However, Strabo (1.2.10) contains references to the fact that in antiquity the Black Sea was also called simply “sea” (pontos).

In Ancient Rus' X-XVI centuries in chronicles the name “Russian Sea” was found; in some sources the sea is called “Scythian”. Modern name“Black Sea” has found its corresponding reflection in most languages: Greek. Μαύρη θάλασσα, Bulgarian. Black Sea, cargo. შავი ზღვა, rum. Marea Neagră, English. Black Sea, tour. Karadeniz, Ukrainian Chorne more, etc. The earliest sources mentioning this name date back to the 13th century, but there are certain signs that it was used earlier. There are a number of hypotheses regarding the reasons for this name:

The Turks and other conquerors who tried to conquer the population of the sea coast met fierce resistance from the Circassians, Circassians and other tribes, for which they called the sea Karadengiz - Black, inhospitable.

Another reason, according to some researchers, may be the fact that during storms the water in the sea becomes very dark. However, storms in the Black Sea are not too frequent, and the water darkens during storms in all the seas of the earth. Another hypothesis about the origin of the name is based on the fact that metal objects (for example, anchors) lowered into sea water deeper than 150 m at long time, became covered with a black coating due to the action of hydrogen sulfide.

Another hypothesis is related to the “color” designation of the cardinal directions adopted in a number of Asian countries, where “black” denoted the north, respectively, the Black Sea - the northern sea.

One of the most common hypotheses is the assumption that the name is associated with memories of the Bosphorus breakthrough 7500-5000 years ago, which resulted in a catastrophic rise in sea level by almost 100 meters, which in turn led to the flooding of a vast shelf zone and the formation of the Sea of ​​Azov .

There is a Turkish legend according to which a heroic sword rests in the waters of the Black Sea, which was thrown there at the request of the dying wizard Ali. Because of this, the sea is agitated, trying to splash out from its depths lethal weapon, and is painted black.

The shores of the Black Sea are slightly indented and mainly in its northern part. The only large peninsula is Crimean. Largest bays: Yagorlytsky, Tendrovsky, Dzharylgachsky, Karkinitsky, Kalamitsky and Feodosia in Ukraine, Varna and Burgassky in Bulgaria, Sinopsky and Samsunsky - on the southern shores of the sea, in Turkey. In the north and northwest, estuaries flood at the confluence of rivers. The total length of the coastline is 3400 km.

A number of sections of the sea coast have their own names: the southern coast of Crimea in Ukraine, the Black Sea coast of the Caucasus in Russia, the Rumelian coast and the Anatolian coast in Turkey. In the west and north-west the banks are low-lying, steep in places; in Crimea - mostly lowland, with the exception of the southern mountainous shores. On the eastern and southern shores, the spurs of the Caucasus and Pontic mountains come close to the sea.

There are few islands in the Black Sea. The largest are Berezan and Zmeiny (both with an area of ​​less than 1 km²).

The following largest rivers flow into the Black Sea: Danube, Dnieper, Dniester, as well as smaller Mzymta, Bzyb, Rioni, Kodor (Kodori), Inguri (in the east of the sea), Chorokh, Kyzyl-Irmak, Ashley-Irmak, Sakarya (in the south ), Southern Bug (in the north). The Black Sea fills an isolated depression located between Southeast Europe and the Asia Minor peninsula. This depression was formed in the Miocene era, during the process of active mountain building, which divided the ancient Tethys Ocean into several separate bodies of water (from which, in addition to the Black Sea, the Azov, Aral and Caspian seas were subsequently formed).

One of the hypotheses for the origin of the Black Sea (in particular, the conclusions of the participants in the international oceanographic expedition on the scientific vessel “Aquanaut” in 1993) states that 7,500 years ago it was the deepest on earth freshwater lake, the level was more than a hundred meters below the modern one. At the end ice age The level of the World Ocean rose and the Bosphorus Isthmus was broken. A total of 100 thousand km² (the most fertile lands already cultivated by people) were flooded. The flooding of these vast lands may have become the prototype of the myth of the Great Flood. The emergence of the Black Sea, according to this hypothesis, was supposedly accompanied by the mass death of all the freshwater living world of the lake, the decomposition product of which - hydrogen sulfide - reaches high concentrations on the bottom of the sea.

The Black Sea depression consists of two parts - western and eastern, separated by a rise, which is a natural continuation of the Crimean peninsula. The northwestern part of the sea is characterized by a relatively wide shelf strip (up to 190 km). The southern coast (belonging to Turkey) and the eastern (Georgia) are steeper, the shelf strip does not exceed 20 km and is cut by a number of canyons and depressions. Depths off the coast of Crimea and the Black Sea coast of the Caucasus are increasing extremely quickly, reaching levels of over 500 m already a few kilometers from the coastline. The sea reaches its maximum depth (2210 m) in the central part, south of Yalta.

As part of the rocks that make up the seabed, coastal zone Coarse sediments predominate: pebbles, gravel, sand. As they move away from the coast, they are replaced by fine-grained sands and silts. Shell rocks are widespread in the northwestern part of the Black Sea; Pelitic silts are common on the slope and bed of the sea basin.

Among the main mineral resources, deposits of which are found on the seabed: oil and natural gas on the northwestern shelf; coastal placers of titanomagnetite sands (Taman Peninsula, Caucasus coast). The Black Sea is the world's largest meromictic (with unmixed water levels) body of water. The upper layer of water (mixolimnion), lying down to a depth of 150 m, is cooler, less dense and less saline, saturated with oxygen, separated from the lower, warmer, saltier and dense layer saturated with hydrogen sulfide (monimolimnion) by a chemocline (the boundary layer between aerobic and anaerobic waters). zones). There is no single generally accepted explanation for the origin of hydrogen sulfide in the Black Sea. There is an opinion that hydrogen sulfide in the Black Sea is formed mainly as a result of the activity of sulfate-reducing bacteria, pronounced stratification of water and weak vertical exchange. There is also a theory that hydrogen sulfide was formed as a result of the decomposition of freshwater animals that died during the penetration of salt water into the Mediterranean sea ​​waters during the formation of the Bosphorus and Dardanelles.

Some studies in recent years suggest that the Black Sea is a gigantic reservoir of not only hydrogen sulfide, but also methane, most likely also released during the activity of microorganisms, as well as from the bottom of the sea.

The water balance of the Black Sea consists of the following components:

• atmospheric precipitation (230 km³ per year);
• continental runoff (310 km³ per year);
• water supply from the Sea of ​​Azov (30 km³ per year);
• evaporation of water from the sea surface (-360 km³ per year);
• removal of water through the Bosphorus Strait (-210 km³ per year).

The amount of precipitation, inflow from the Sea of ​​Azov and river runoff exceeds the amount of evaporation from the surface, as a result of which the level of the Black Sea exceeds the level of the Marmara Sea. Thanks to this, an upper current is formed, directed from the Black Sea through the Bosphorus Strait. The lower current observed in lower layers of water is less pronounced and is directed through the Bosphorus in the opposite direction. The interaction of these currents additionally supports the vertical stratification of the sea, and is also used by fish for migration between seas.

It should be noted that due to the difficult exchange of water with the Atlantic Ocean, there are practically no ebbs and flows in the Black Sea. The circulation of water in the sea covers only the surface layer of water. This layer of water has a salinity of about 18 ppm (in the Mediterranean - 37 ppm) and is saturated with oxygen and other elements necessary for the activity of living organisms. These layers in the Black Sea are subject to circular circulation in an anticyclonic direction along the entire perimeter of the reservoir. At the same time, in the western and eastern parts of the sea there are water circulations in the cyclonic direction. The temperature of the surface layers of water, depending on the time of year, ranges from 8 to 30 °C.

The lower layer, due to its saturation with hydrogen sulfide, does not contain living organisms, with the exception of a number of anaerobic sulfur bacteria (the waste product of which is hydrogen sulfide). Salinity here increases to 22-22.5 ppm, the average temperature is ~8.5°C.

The climate of the Black Sea, due to its mid-continental position, is mainly continental. Only the southern coast of Crimea and the Black Sea coast of the Caucasus are protected by mountains from cold northern winds and, as a result, have a mild Mediterranean climate.

The weather over the Black Sea is significantly influenced by the Atlantic Ocean, over which most of the cyclones that bring to the sea originate. bad weather and storms. On the north-eastern coast of the sea, especially in the Novorossiysk region, low mountains are not a barrier to cold northern air masses, which, passing through them, cause a strong cold wind (bora), local residents call it Nord-Ost. Southwestern winds usually bring warm and fairly humid Mediterranean air masses to the Black Sea region. As a result, most of the sea area is characterized by warm, wet winters and hot, dry summers.

The average January temperature in the northern part of the Black Sea is −3 °C, but can drop to −30 °C. In the territories adjacent to the southern coast of Crimea and the Caucasus coast, winter is much milder: temperatures rarely drop below 0 °C. Snow, however, periodically falls in all areas of the sea. The average July temperature in the north of the sea is 22-23°C. Maximum temperatures not so high due to the softening effect of the water reservoir and usually do not exceed 35 °C.

The greatest amount of precipitation in the Black Sea region falls on the coast of the Caucasus (up to 1500 mm per year), the least in the northwestern part of the sea (about 300 mm per year). Cloud cover for the year averages 60% with a maximum in winter and a minimum in summer.

The waters of the Black Sea, as a rule, are not subject to freezing, with the exception of the coastal part in the north of the reservoir. Coastal waters in these places freeze for up to a month or more; estuaries and river branches - up to 2-3 months.

The flora of the sea includes 270 species of multicellular green, brown, and red bottom algae (Cystoseira, Phyllophora, Zostera, Cladophora, Ulva, Enteromorpha, etc.). The phytoplankton of the Black Sea contains at least six hundred species. Among them are dinoflagellates - armored flagellates (prorocentrum micans, ceratium furca, small Scrippsiella trochoidea, etc.), dinoflagellates (dinophysis, protoperidinium, alexandrium), various diatoms, etc. The fauna of the Black Sea is noticeably poorer than the Mediterranean. The Black Sea is home to 2.5 thousand species of animals (of which 500 species are unicellular, 160 species of vertebrates - fish and mammals, 500 species of crustaceans, 200 species of mollusks, the rest are invertebrates different types), for comparison, in the Mediterranean there are about 9 thousand species. Among the main reasons for the relative poverty of the marine fauna: a wide range of water salinities, moderately cold water, and the presence of hydrogen sulfide at great depths.

In this regard, the Black Sea is suitable for the habitat of fairly unpretentious species, at all stages of development of which great depths are not required.

At the bottom of the Black Sea live mussels, oysters, pecten, as well as the predator mollusk rapana, brought with ships from Far East. Numerous crabs live in the crevices of the coastal rocks and among the stones, there are shrimps, various types of jellyfish are found (the most common are Corneros and Aurelia), sea anemones, and sponges.

Among the fish found in the Black Sea: various types of gobies (bighead goby, whip goby, round goby, martovy goby, rotan goby), Azov anchovy, Black Sea anchovy, dogfish shark, glossa flounder, mullet of five species, bluefish, hake (hake), sea ruff, red mullet (common Black Sea mullet), haddock, mackerel, horse mackerel, Black Sea-Azov herring, Black Sea-Azov sprat, etc. There are sturgeon (beluga, stellate sturgeon, Black Sea-Azov ( Russian) and Atlantic sturgeon).

Among the dangerous fish of the Black Sea are the sea dragon (the most dangerous - the spines of the dorsal fin and gill covers are poisonous), the Black Sea and noticeable scorpionfish, stingray ( catfish) with poisonous spines on its tail.

The most common birds are gulls, petrels, diving ducks, cormorants and a number of other species. Mammals are represented in the Black Sea by two species of dolphins (the common dolphin and the bottlenose dolphin), the Azov-Black Sea harbor porpoise (often called the Azov dolphin), and the white-bellied seal.

Some species of animals that do not live in the Black Sea are often brought into it through the Bosporus and Dardanelles straits by currents or swim on their own.

The history of the study of the Black Sea began in ancient times, along with the voyages of the Greeks, who founded their settlements on the seashore. Already in the 4th century BC, peripluses were compiled - ancient sailing directions of the sea. Subsequently, there is fragmentary information about the voyages of merchants from Novgorod and Kyiv to Constantinople.

Another milestone on the path to exploring the Black Sea was the voyage of the ship “Fortress” from Azov to Constantinople in 1696. Peter I, equipping the ship for voyage, gave the order to carry out cartographic work along the route of its movement. As a result, a “direct drawing of the Black Sea from Kerch to Tsar Grad” was drawn up, and depth measurements were taken.

More serious studies of the Black Sea relate to end of XVIII-XIX centuries. In particular, at the turn of these centuries, Russian scientists, academicians Peter Pallas and Middendorf, studied the properties of the waters and fauna of the Black Sea. In 1816, a description of the Black Sea coast appeared, made by F. F. Bellingshausen, in 1817 the first map of the Black Sea was published, in 1842 - the first atlas, in 1851 - the Black Sea navigational guide.

Systematic scientific research of the Black Sea began with two events at the end of the 19th century - the study of the Bosphorus currents (1881-1882) and the conduct of two oceanographic depth-finding expeditions (1890-1891).

Since 1871, a biological station has been operating in Sevastopol (now the Institute of Biology south seas), engaged in systematic research of the living world of the Black Sea. At the end of the 19th century, an expedition led by I. B. Spindler discovered the saturation of the deep layers of the sea with hydrogen sulfide; Later, a member of the expedition, the famous Russian chemist N.D. Zelinsky, gave an explanation for this phenomenon.

The study of the Black Sea continued after the October Revolution of 1917. In 1919, an ichthyological station was organized in Kerch (later transformed into the Azov-Black Sea Institute of Fisheries and Oceanography, now the Southern Research Institute of Marine Fisheries and Oceanography (YugNIRO)). In 1929, a marine hydrophysical station was opened in the Crimea, in Katsiveli (now a branch of the Sevastopol Marine Hydrophysical Institute of the National Academy of Sciences of Ukraine).

In Russia, the main research organization conducting the study of the Black Sea is the Southern Branch of the Institute of Oceanology of the Russian Academy of Sciences (Gelendzhik, Blue Bay) and a number of others.

The Black Sea is of great transport importance for the economies of the states washed by this body of water. A significant volume of maritime traffic consists of tanker flights that ensure the export of oil and petroleum products from the ports of Russia (primarily from Novorossiysk and Tuapse) and the ports of Georgia (Batumi). However, the volumes of hydrocarbon exports are significantly limited by the limited throughput capacity of the Bosporus and Dardanelles straits. The largest oil terminal for receiving oil as part of the Odessa-Brody oil pipeline was created in Ilyichevsk. There is also a project for the construction of the Burgas - Alexandroupolis oil pipeline bypassing the Black Sea straits. Novorossiysk oil terminals are capable of receiving supertankers. In addition to oil and its products, metals, mineral fertilizers, machinery and equipment, timber, lumber, grain, etc. are exported from the Russian and Ukrainian ports of the Black Sea. The main volumes of imports into the Black Sea ports of Russia and Ukraine are consumer goods, food products, a number of raw materials, etc. Container transportation is widely developed in the Black Sea basin, and there are large container terminals. Transportation using lighters is developing; There are railway ferry crossings Ilyichevsk (Ukraine) - Varna (Bulgaria) and Ilyichevsk (Ukraine) - Batumi (Georgia). Marine passenger transportation is also developed in the Black Sea (however, after the collapse of the USSR, its volume decreased significantly). The international transport corridor TRACECA (Transport Corridor Europe - Caucasus - Asia, Europe - Caucasus - Asia) passes through the Black Sea. The Black Sea ports are the end points of a number of Pan-European transport corridors. Most big cities-ports on the Black Sea: Novorossiysk, Sochi, Tuapse (Russia); Burgas, Varna (Bulgaria); Batumi, Sukhumi, Poti (Georgia); Constanta (Romania); Samsun, Trabzon (Türkiye); Odessa, Ilyichevsk, Yuzhny, Kerch, Sevastopol, Yalta (Ukraine). Along the Don River, which flows into the Sea of ​​Azov, there is a river waterway, connecting the Black Sea with the Caspian Sea (via the Volga-Don Shipping Canal and the Volga), with the Baltic Sea and the White Sea (via the Volga-Baltic Waterway and the White Sea-Baltic Canal). The Danube River is connected to the North Sea through a system of canals. A unique deep-sea gas pipeline, the Blue Stream, connects Russia and Turkey, is laid along the bottom of the Black Sea. The length of the underwater part of the gas pipeline, running between the village of Arkhipo-Osipovka on the Black Sea coast of the Caucasus and the Turkish coast, 60 km from the city of Samsun, is 396 km. There are plans to expand the capacity of the gas pipeline by laying an additional branch of the pipe.

The following fish species are of commercial importance in the Black Sea: mullet, anchovy (anchovy), mackerel, horse mackerel, pike perch, bream, sturgeon, herring. Main fishing ports: Odessa, Kerch, Novorossiysk, etc.

IN last years In the 20th - early 21st centuries, fishing decreased significantly due to overfishing and deterioration of the ecological state of the sea. Prohibited bottom trawling and poaching are also a significant problem, especially for sturgeon. Thus, in the second half of 2005 alone, specialists from the Black Sea State Basin Department for the Protection of Aquatic Living Resources of Ukraine (“Chernomorrybvod”) uncovered 1,909 violations of fishery protection legislation in the Crimea and seized 33 tons of fish caught with illegal fishing gear or in prohibited places.

Favorable climatic conditions in the Black Sea region determine its development as an important resort region. The largest resort areas on the Black Sea include: the southern coast of Crimea (Yalta, Alushta, Sudak, Koktebel, Feodosia) in Ukraine, the Black Sea coast of the Caucasus (Anapa, Gelendzhik, Sochi) in Russia, Pitsunda, Gagra and Batumi in Georgia, Golden Sands and Sunny Beach in Bulgaria, Mamaia, Eforie in Romania.

The Black Sea coast of the Caucasus is the main resort region of the Russian Federation. In 2005, about 9 million tourists visited it; in 2006, according to officials' forecasts Krasnodar region, this region should have been visited by at least 11-11.5 million vacationers. There are over 1,000 boarding houses, sanatoriums and hotels on the Russian Black Sea coast, and their number is constantly growing. A natural continuation of the Russian Black Sea coast is the coast of Abkhazia, the most important resorts of which Gagra and Pitsunda were popular back in Soviet time. The development of the resort industry on the Black Sea coast of the Caucasus is hampered by the relatively short (for example, compared to the Mediterranean) season, environmental and transport problems, and in Abkhazia, also by the uncertainty of its status and the threat of a new outbreak of military conflict with Georgia.

The Black Sea coast and the river basins flowing into it are areas with high anthropogenic impact, densely populated by people since ancient times. The ecological state of the Black Sea is generally unfavorable.

Among the main factors that disturb the balance in the ecological system of the sea, the following should be highlighted:

Severe pollution of rivers flowing into the sea, especially with runoff from fields containing mineral fertilizers, especially nitrates and phosphates. This entails overfertilization (eutrophication) of sea waters, and, as a consequence, rapid growth of phytoplankton (“blooming” of the sea - intensive development of blue-green algae), a decrease in water transparency, and the death of multicellular algae.

Water pollution with oil and oil products (the most polluted areas are the western part of the sea, which accounts for the largest volume of tanker traffic, as well as port waters). As a consequence, this leads to the death of marine animals caught in oil spills, as well as atmospheric pollution due to the evaporation of oil and petroleum products from the surface of the water.

Pollution of sea waters with human waste - discharge of untreated or insufficiently treated waste Wastewater and so on.

Massive fishing.

Prohibited but widely used bottom trawling, which destroys bottom biocenoses.

Changes in composition, reduction in the number of individuals and mutation of the aquatic world under the influence of anthropogenic factors (including replacement of indigenous species natural world exotic, resulting from human influence). For example, according to experts from the Odessa branch of YugNIRO, in just one decade (from 1976 to 1987) the number of Black Sea bottlenose dolphins decreased from 56 thousand to seven thousand individuals.

According to a number of experts ecological state The Black Sea has worsened over the past decade despite a decline in economic activity in a number of Black Sea countries.

The President of the Crimean Academy of Sciences, Viktor Tarasenko, expressed the opinion that the Black Sea is the dirtiest sea in the world.

For security environment in the Black Sea region in 1998, the ACCOBAMS agreement (Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area) was adopted, where one of the main issues is the protection of dolphins and whales. The main international document regulating the protection of the Black Sea is the Convention for the Protection of the Black Sea from Pollution, signed by six Black Sea countries - Bulgaria, Georgia, Russia, Romania, Turkey and Ukraine in 1992 in Bucharest (Bucharest Convention). Also in June 1994, representatives of Austria, Bulgaria, Croatia, the Czech Republic, Germany, Hungary, Moldova, Romania, Slovakia, Slovenia, Ukraine and European Union The Convention on Cooperation for the Protection and sustainable development Danube River. As a result of these agreements, the Black Sea Commission (Istanbul) and the International Commission for the Protection of the Danube River (Vienna) were created. These bodies perform the function of coordinating environmental programs implemented within the framework of the conventions. Every year on October 31, all countries of the Black Sea region celebrate International Black Sea Day.

The Black Sea is an inland sea of ​​the Atlantic Ocean, washing the shores of Ukraine, Russia, Georgia, Romania, Bulgaria, and Turkey.

Area - 422 thousand km2, length between western and eastern points - about 1167 km, between northern and southern - 624 km. The largest peninsula is Crimean, the largest bays (off the coast of Ukraine) are Karkinitsky, Kalamitsky, Feodosiyskaya, Dzharylgachsky. The largest island off the coast of Ukraine is Zmeiny. The average depth is 1271 m, the maximum is 2245 m. The shores of the Black Sea are poorly dissected, most often mountainous, steep, but within the continental part of Ukraine they are flat.
Within Ukraine, large rivers flow into the Black Sea: Danube, Dniester, Southern Bug, Dnieper. Many resorts: Sochi, Gelendzhik, resorts of Crimea, Abkhazia, Bulgaria.
Most of the sea is located in the subtropical zone. Winter is warm and humid. The air temperature in January over the Black Sea is -1 ... + 8 ° C, the surface water temperature is + 8 ° ... 9 ° C, except in the northwestern and northeastern parts, where the sea freezes in severe winters. Summer is hot and dry. Air temperature +22 ... 25 ° C, surface water temperature H24 ... 26 ° C. Average precipitation increases from west to east from 200-600 to 2000 mm or more. 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, living mainly in the upper layer (above the hydrogen sulfide zone). Anchovy, horse mackerel, mullet, flounder, mackerel, algae and invertebrates (mussels, shrimp, oysters) are of industrial importance. Every year the sea provides up to 300 thousand tons of biological resources. Explored industrial reserves natural gas and oil. The mud of the Black Sea estuaries has medicinal value. 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 water area exceeds 420 thousand km2. The sea fills a large tectonic depression. Its maximum depth is 2245 m. The largest bays are Dzharylgachsky, Karkinitsky, Kalamitsky, Feodosiyskaya, Sivash, Obitichna, Berdyansk. The rivers Danube, Dnieper, Dniester, and Southern Bug flow into the Black Sea. In areas between the rivers of the coast there are bodies of water connecting to the sea - estuaries. Of these, on the Black Sea coast there are the Dniester, Khadzhibey, Kuyalnitsky, Tiligulsky, Dnieper estuaries, on Azov coast- Utlyutsky, Molochny. The most peninsula of the Black Sea is the Crimean, which is connected to the mainland by the Perekop Isthmus. In the Sea of ​​Azov, elongated areas of land - spits - attract attention. The largest among them is the Arabat Strelka Spit. In the Black Sea, the largest island is Dzharylgach.

The Kerch Strait connects the Black Sea with the Azov Sea. 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, which are associated with rain and foggy weather. In summer, the Black Sea is under the influence of the Azores High, due to which cloudless weather prevails here, thunderstorms and tornadoes are rare occurrences.

Sea level fluctuations associated with high and low tides are insignificant, their amplitude is only 10 cm. Fluctuations under the influence of wind activity reach 1.5 m. 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 severe 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 increases to 22.5%. Compare these indicators with these: the average salinity of the World Ocean is 35% o, Mediterranean Sea- up to 38, and the Red Sea - 40% o. Find out why the salinity of the Black Sea waters is much lower.

Characteristic feature natural conditions The Black Sea is the existence of a permanent layer of hydrogen sulfide at depths below 100-120 m. This layer is inhabited by bacteria that use hydrogen sulfide. An important fact is that the hydrogen sulfide layer makes up 87% of the volume of the entire Black Sea. 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.

Every year, up to 300 thousand tons are taken out of the Black Sea. Biological resources. Construction sand, gravel, and flammable gas are also mined here; The search for oil fields on the shelf continues.

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Usually, scientists, explaining the presence of a huge mass of hydrogen sulfide in the Black Sea (BS), explain this by the uniqueness of this body of water. The following arguments are given:

1. The Black Sea is a closed basin, it is connected to the world ocean by narrow straits.


2. Large rivers discharge large amounts of organic matter into the Black Sea.


3. The World Cup has great depth and a sharp drop from the continental shelf to depth.


4. The high salinity of the deep layers of the Black Sea does not allow oxygen to penetrate downwards and this contributes to the formation and accumulation of hydrogen sulfide.


5. Due to the unique hydrology of the Black Sea, there is no mixing of layers in it.

Fig 1. Cross-section of the Black Sea.

Looking at this map, we quickly become convinced that the World Cup is not unique in its characteristics.

Rice. 2 Reliefs of the seas.
The Mediterranean Sea (MS) is also closed and is connected to the ocean by the relatively narrow Gibraltar. At the same time, the maximum depth of the SM is 5121 m, which significantly exceeds the depth of the CM (2210 m). The average depths of both seas have approximately the same value - 1240 and 1541 m. At the same time, the map shows that the differences in depths in the SM are almost greater than in the WC.
Regarding salinity, the salinity of the SM is significantly higher than the salinity of the BS (36-39.5 ‰ versus 15-18 ‰), which will undoubtedly further prevent the penetration of oxygen to depth. At the same time, the contribution of organic matter by the rivers of the Mediterranean basin is undoubtedly greater, not even because of the fact that it flows into more rivers, but because industrialized EU countries are located on the shores of this basin. They are densely populated, undergo intensive agricultural activities, and large cities dump enormous amounts of waste. At the same time, in the EU countries there was no such decline in all economic indicators as in the countries former USSR and Eastern Europe.
Despite all this, hydrogen sulfide reserves are not formed in the SM.
But let's take the Caspian Sea (CM). It is generally a salt lake.

Fig.3 Caspian Sea.

The depth of the CM is quite decent - 1025 m. At the same time, we observe a significant difference in depth, almost a cliff in the area of ​​​​the confluence of the Kura River. And in the middle part of the pool too. There is no doubt about organics - pollution from oil production is added to the drains of the mighty Volga, Kura and Ural. But there are no deep layers of hydrogen sulfide in the CM either! Although salinity in the southern part of the sea reaches 28 ‰.
There remains one and final argument for the uniqueness of the FM - the absence of mixing of layers. Why do they mix in other seas, but not in the Black Sea? It is worth noting that the methodology itself for determining the parameters of sea water, deep currents and salinities is very complex. The fact is that such work requires significant costs. Oceanographic vessels are incredibly expensive to operate. It would be much better to spend money on building cruise ships, sort of floating paradises, and then sink and burn them in hopes of receiving insurance.

Rice. 4 Oceanographic vessels.

In addition, the volume of such research is extremely large. With great difficulty, we only had some idea of ​​the surface of the oceans and seas, and if we also take their thickness... this is a colossal amount of information. Often even submarines are lost due to lack of such knowledge. They fall into deeper layers with a lower density, as if breaking through the ice of a denser layer. How these layers are formed, where they are located and why - all of this is still a mystery for oceanology.
Therefore, it is premature to say with confidence that there is no vertical mixing of layers in the Black Sea for such and such a reason. But it is missing, and that is a fact.
However, hydrogen sulfide is successfully formed in other seas and basins. Accelerated formation of hydrogen sulfide has been observed, for example, in Norwegian fjords. Driving by car to Odessa past the estuaries, we are forced to plug our noses and close the car windows - the stink of hydrogen sulfide is unbearable. This gas is also formed in other seas and even in lakes.
Not far from the resort of Playa del Carmen there is a cave filled with fresh water, Cenote Angelita. Lost in the impenetrable jungle of Mexico, the cave is fraught with many surprises, one of which is an amazing underwater lake! At the bottom of this lake there is also a hydrogen sulfide layer.

Rice. 5 Underwater lake in Mexico.

From this we can conclude that the Black Sea basin is absolutely not unique in this regard and the presence of 3.1 billion tons of hydrogen sulfide in it is due to other reasons.
Here I would like to mention another strange event. Recently, the American Landstat satellite took another picture Dead Sea(MM), which shocked scientists. In just one orbital revolution, the color of this body of water changed to completely black. Oceanologists came to the conclusion that the sea instantly “turned over.” The surface layers went down, and those saturated with hydrogen sulfide floated up.

Rice. 6 Dead Sea.

This can happen when a critical density gradient is reached and is quite possible with our FM. Water saturated with hydrogen sulfide is black. Here is your explanation - why the World Cup is called black. But before it was called Russian, the Greeks called it hospitable. Only then did it suddenly turn black. Did a “turning over” of layers happen in ancient times?
It is worth noting, and scientists always point out this, that the bottom of the World Cup does not have a solid granite slab. That is, the Black Sea lies directly on the basalts of the mantle and is a remnant ancient ocean. The true depth of the Black Sea reaches 16 km, the depression is filled with sediments.
A simple calculation shows that the volume of sedimentary substances is:
The area of ​​the deep-sea part is 211,000 sq. km. * the thickness of the sedimentary layer is 16 km. = 3 million 376 thousand cubic meters km.
Which exceeds the volume of the entire World Cup by more than 6 times.
At the same time, research by the expedition of J. Murray in 1910, part of the Meteor expedition, research on the cable steamer Lord Kelvin, the expedition of W. Snell and many others showed that the layer of sedimentary substances at the bottom of the world's oceans is 23-35 cm. That is, precipitation accumulate extremely long and slowly.
How could a layer of sediment 16 km thick accumulate in the World Cup?
It should be noted that back in the early 1920s, hydrogen sulfide was located much deeper. In 1891, Professor A. Lebedintsev raised the first water sample from the depths of the Black Sea. The sample showed that the water below 183 meters is saturated with hydrogen sulfide. Nowadays, poisonous and explosive gas is located at depths of 18 m, and sometimes even breaks through to the surface, as happened during the Crimean earthquake of 1927. Then an entire flotilla of fishermen burned in flames on the surface of the sea.

Rice. 7 World Cup.
This means that the process of hydrogen sulfide formation continues and proceeds quite quickly. And this is not due to an increase in the discharge of organic substances into the Black Sea - it has even decreased. This is the result of rotting without oxygen of a huge amount of sediment that ended up in the World Cup unknown, as in the recent past.
We know that the breakthrough of the Bosporus and Dardanelles occurred in historical period, this is noted in the chronicles. It is also known that on ancient maps the World Cup is depicted as a rounded basin, without peninsulas, and Crimea is depicted as a flat coast.

There is no need to make idiots out of our ancestors, as if they, when drawing Crimea, did not see that it was a peninsula jutting out 300 km into the sea. It’s just that the old maps show the World Cup as it was. And this was a lake in the deep-water part of the modern World Cup. I have already written () that presumably, as a result of a huge tsunami, and even more likely - hyper-precipitation, super-powerful rains, all the biomass from the Central Russian Upland, the southern part of Ukraine, was washed away into the Black Sea basin. As a result, we have the absence of thick layers of fertile soils in the Non-Black Earth Region, wide floodplains of rivers that do not correspond to their geological history, accumulations of black soil in places where it was washed, the absence of trees in the steppe zone of Ukraine, a thick layer of sediment in the steppe part of Crimea.
At the bottom of the World Cup lie the remains of our ancient civilization. There is vegetation, soil, dead animals and people, flooded cities and river beds. The once wooded, wildlife-filled, fertile south of Ukraine has turned into a dry steppe. This happened not as long ago as scientists would like us to believe. You can still find references to this fertile land in historical documents. Our ancestors tried to protect themselves from the elements; they built colossal hydraulic structures along large rivers - the Serpentine Shafts, which they are now trying to pass off as defensive structures against the small number of nomads, who were only able to gather as a gang, but not into an army.

Rice. 8 Serpentine shafts.

The Crimean Isthmus was also dug up, and a shaft was made separating the Kerch Peninsula. Everything for protection from powerful mudflows and floods.
The remnants of our civilization continue to “gas” at the bottom of the World Cup. This is precisely the uniqueness that is inherent in the former Russian, and now Black Sea.

• All rights reserved Alexandra Lorenz

Hydrogen sulfide in the Black Sea - one of the most famous and unusual properties of the sea. But the excess of hydrogen sulfide in the deep waters of the Black Sea is only one of the consequences of the fact that deeper than 200 meters - there is no oxygen in the Black Sea water; neither animals nor plants can live there. At depths from 200 meters to the very bottom of the Black Sea, only bacteria that produce hydrogen sulfide live. There is no other sea like this in the world.
It turns out like this:

Oxygen penetrates into water through the surface of the sea - from the air; and also - it is formed in the upper illuminated layer of water (photic zone) when photosynthesis of algae plankton.

In order for oxygen to reach the depths, the sea must mix - due to waves and vertical currents. And in the Black Sea, the water mixes very weakly; It takes hundreds of years for water from the surface to reach the bottom. Reasons for this unusual phenomenon the following:

In the Black Sea, due to its desalination by rivers, there are two masses, two layers of water that weakly mix with each other.

The surface layer of the Black Sea water - to a depth of approximately 100 meters - is predominantly of river origin. At the same time, saltier (and therefore heavier) water from the Sea of ​​Marmara enters the depths of the sea - it flows along the bottom of the Bosphorus Strait (Lower Bosphorus Current) and sinks deeper. Therefore, the salinity of the bottom layers of the Black Sea water reaches 30‰ (grams of salt per liter of water).

The change in water properties with depth is not smooth: from the surface to 50-100 meters salinity changes quickly - from 17 to 21 ‰, and then further - to the bottom - it increases evenly. In accordance with the salinity, the density of water.

Temperature on the sea surface is always determined by air temperature. And the temperature of the deep waters of the Black Sea is all year round 8-9 o C. From the surface to a depth of 50-100 meters, the temperature, like salinity, changes quickly - and then remains constant until the very bottom.

These are the two masses of Black Sea water: superficial- desalinated, lighter and closer in temperature to air (in summer it is warmer than deep waters, and in winter it is colder); And deep- saltier and heavier, with a constant temperature.

The layer of water from 50 to 100 meters is called the boundary layer- this is the boundary between two masses of Black Sea water, a boundary that prevents mixing. Its more accurate name is cold boundary layer: it is always colder than deep waters, since, cooling in winter to 5-6 o C, it does not have time to warm up during the summer.

A layer of water in which its temperature changes sharply is called thermocline; layer of rapid salinity change - halocline, water density - pycnocline. All these sudden changes properties of water in the Black Sea are concentrated in the boundary layer region.

Delamination - stratification of Black Sea water by salinity, density and temperature - prevents vertical mixing of the sea and enrichment of the depths with oxygen. In addition, all the rapidly developing Black Sea life breathes - planktonic crustaceans, jellyfish, crabs, fish, dolphins breathe, even the algae themselves breathe - they consume oxygen.

When living organisms die, their remains become food for saprotrophic bacteria. During bacterial decomposition of the dead organic matter(rotting) uses oxygen. With depth, decomposition begins to dominate the processes of creating living matter by planktonic algae, and oxygen consumption during respiration and decay becomes more intense than its production during photosynthesis. Therefore, the further from the surface of the sea, the less oxygen remains in the water. In the aphotic zone of the sea (where sunlight does not penetrate), under the cold intermediate layer - below 100 meters depth, oxygen is no longer produced, but only consumed; It does not penetrate here due to mixing - this is prevented by the stratification of waters.

As a result, there is only enough oxygen for animal and plant life in the upper 150 meters of the Black Sea. Its concentration decreases with depth, and the bulk of life in the sea - the biomass of the Black Sea - is concentrated above 100 meters depth.

In the depths of the Black Sea, below 200 meters, there is no oxygen at all, and only anaerobic saprotrophic bacteria live there, continuing the decomposition of the remains of living things sinking from the upper layer of the sea. During anaerobic (oxygen-free) decomposition of the remains, hydrogen sulfide is formed - a substance that is toxic to both animals and plants (it blocks the respiratory chain of mitochondria). The source of sulfur is sulfur-containing amino acids of proteins, and, to a lesser extent, seawater sulfates, used by some types of bacteria to oxidize organic matter.

This is how it turns out that 90% of the water mass of the Black Sea is almost lifeless. But in any other sea or ocean, almost all life is concentrated in the upper, 100-200-meter layer of water - just like here. True, due to the lack of oxygen and the presence of hydrogen sulfide in the water, there is no deep-sea fauna in the Black Sea , this reduces its biodiversity even further, in addition to the effects of low salinity. For example, no predatory fish depths with huge toothy mouths, in front of which luminous baits are hung.

Sometimes they say that hydrogen sulfide appeared in the Black Sea as a result of its pollution, that hydrogen sulfide is becoming more and more abundant, that the sea is on the verge of disaster... Indeed, overfertilization - eutrophication of the Black Sea by runoff from agricultural fields in the 1970s-80s, caused a rapid growth of “weed” marine vegetation - some types of phytoplankton, filamentous algae - “mud”, more organic remains began to form, from which hydrogen sulfide is formed during decay (more on this at the end of the page Changes in the Black Sea ecosystem). But this “extra” hydrogen sulfide did not bring significant changes to the equilibrium that had developed over millennia. And certainly - there is no danger of an explosion of hydrogen sulfide - in order for a gas bubble to form, the concentration of molecules of this substance in water must be orders of magnitude greater than the real one (8-10 mg/l at depths of 1000-2000m) - check using formulas from school chemistry courses and physics.

In summer, especially near the coast, a variable summer thermocline- the boundary between sun-warmed surface water, in which people bathe, and cold deep water. The thermocline drops as the water warms up in the summer, sometimes reaching depths of more than 40 meters in August.

Summer thermocline - a thin layer of water, from a few centimeters to several meters thick; often - it is clearly visible under water, and is very well felt by divers - by diving a few meters towards the bottom, you can get from 20-degree to 12-degree water.

The summer coastal thermocline is easily destroyed by a storm or strong wind blowing from the shore - the water near the shore cools.

Bottom relief of the Black Sea . The Black Sea is deep; The central part of its bottom is occupied by a muddy abyssal (i.e., deep) plain lying at a two-kilometer depth, and the slopes of the Black Sea depression are steep. The maximum depth of the Black Sea is 2210 m.

Black Sea shelf - gentle underwater slope, continuation of the coast under water to a depth of 100-150m - near mountainous coasts (Caucasus, Crimea, Anatolia) - no more than a few kilometers from the coastline. Further - it is very steep (up to 20-30 o) continental slope- cliff to depths of more than 1000 meters. The exception is the shallow Northwestern part of the Black Sea - it all belongs to the shelf zone, and, in fact, is not part of the Black Sea depression.

Such a bottom topography also does little to promote intensive exchange of water between the depths of the sea and its surface, since the surface of the sea turns out to be small relative to its volume. The smaller the sea surface for a given volume, the less oxygen per unit volume of sea enters the sea from the air and is created by algae in the illuminated layer of water. Therefore, the shape of the Black Sea depression is not conducive to enriching its depths with oxygen.

Bottom sediments of the Black Sea: whatever the shores and beaches are - sandy, pebble, or rocky - starting from a depth of 25-50 meters, at the bottom of the Black Sea there is sand or gravel. With increasing depth, the surface is covered with fragments of mussel valves, and even deeper - modiola Modiolus phaseolinus, which form phaseolin silt of the shelf.

Data from geological studies of the Black Sea bottom indicate that thickness of the bottom sediment layer accumulated on the abyssal plain over the entire history of the Black Sea - from 8 to 16 km; that is, the depth of sediments is 4-8 times greater than the depth of the water column of the Black Sea. The thickness of the sediment layer is 1.5-2 times greater in the western part of the Black Sea, separated by the central Black Sea meridional uplift - from Anatolia to Crimea. The thickness of the sediment layer on the abyssal plain, accumulated over the last 3000 years of the history of the modern Black Sea, is from 20 to 80 cm in different parts of the bottom.

The Black Sea sediment layer lies on a 5-10 km thick basalt plate covering the Earth's mantle. The Black Sea is characterized by the absence of a continuous intermediate layer of granite between the sediments and the basalt platform; the granite layer is common in continental seas. Elements of the granite layer were found by geologists only in the eastern part of the abyssal plain. Such the bottom structure, like in the Black Sea, is characteristic of the oceans.

Main Black Sea Current 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). Map of the Black Sea This movement of water and its direction is based on the acceleration given to water by the rotation of the Earth - Coriolis force. However, 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 currents of a smaller scale, and sometimes the speed of the jet of the main Black Sea current reaches 100 cm/s.

In the coastal waters of the Black Sea, eddies of the opposite direction to the Rim Current are formed - anticyclonic gyres , they are especially pronounced along the Caucasian and Anatolian coasts. Local alongshore currents in the surface layer of water are usually determined by the wind; their direction can change during the day.

A special type of local flow - draft- forms on flat 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.

Average level Black Sea has increased over the past century by 12cm; this change is masked by strong fluctuations in sea level (up to 20 cm throughout the year) associated with interannual variability of river flow. Recent satellite altimetry data have shown a strong acceleration in Black Sea level rise: up to 20cm/decade(secular trend) in the central part of the sea. A more conservative estimate is 3-4cm/decade. Many experts associate this phenomenon with the melting of polar ice as a result of global warming.

Tidal fluctuations the level of the Black Sea does not exceed 10 cm, since Mediterranean tidal waves are attenuated by the straits, and the size of the Black Sea itself is not large enough for the development of strong tides.

The most noticeable rapid changes in sea level are due to the action of wind. A strong, steady wind from the shore creates surge current: the sea moves away from the coast, its level in a given place decreases, sometimes by up to 30 cm per day. Surface water is replaced by water from the depths. With a steady wind from the sea, the opposite phenomenon is observed - wind surge, sea level rise offshore.

These are - very briefly - the main properties of the modern Black Sea. But it was not always as we know it today; The geography, hydrology, and ecology of the Black Sea have changed many times and greatly. The Black Sea continues to change today:

Just 8,000 years ago it was a lake (it did not have access to the World Ocean) and today it is considered one of the youngest seas on our planet (despite the fact that it is surrounded on all sides by land, two straits - the Dardanelles and the Bosphorus - connect it with the Aegean and Mediterranean by sea).

Due to the fact that it occupies a fairly small area (438,600 sq. km.) and is protected on the northern coast by mountains, the wind does not have time to swing the waves strongly enough, so the storm here is quite a rare event. The concentration of salt in the water is insignificant (it doesn’t sting the eyes), and there are practically no animals dangerous to humans, so it is considered that a holiday on the Black Sea is suitable for children- here they can dive and frolic without fear, becoming acquainted with the marine world for the first time.

Features of the Black Sea

The water on the surface of the Black Sea has a very low concentration of salt, and, therefore, less dense, i.e. light: does not mix with deep layers of water. At any time of the year, the temperature at the sea surface close to air temperature. But water at a depth (more than 100-150 meters) has a completely different density, practically does not contain oxygen (as a result, almost only bacteria live at depth, which produce hydrogen sulfide in the process of their life activity) and, in addition, at any time of the year it has constant temperature +9°C (average depth 1239 m, maximum depth 2208 m).

Quite rare, but still on the Black Sea you can observe such frightening and fascinating a natural phenomenon like a tornado. As a result constant collision of air masses(one of which is formed above the surface Black Sea, and the other in the coastal mountains) the climate here is comfortable for most vacationers and local residents: it is never cold in winter, and the constant sea breeze in summer smoothes out the influence high temperatures and the southern sun.

Countries with beaches on the Black Sea coast

It can be proud of the diversity of its beaches. In the western part on the coast of Crimea and Bulgaria, the beaches are sandy. To the east - in Russia, Abkhazia and Georgia - almost all beaches are pebble (small or large pebbles), with the exception of the Taman Peninsula - the capital of sandy beaches Black Sea Russia.

Flora and fauna of the Black Sea

Habitat conditions in waters and on the coast Black Sea unique: despite the fact that living organisms are almost completely absent in the depths of sea waters, the number of species of plants and living creatures in the coastal zone is enormous! The Black Sea is the only natural body of water on the planet that has a deep division into oxygen (up to 200 m deep) and hydrogen sulfide (at great depths) zones. Moreover, hydrogen sulfide is practically lifeless zone, is 88% of the total volume of the sea.

It is in the remaining layer (12% of the total volume of water) that plant and organic life boils. But how diverse it is! Hundreds of species of plankton, about a thousand species of benthic algae, animals and about 2700 species! Only fish - almost 200 species, invertebrates - about 2100! IN Black Sea There are 4 species of mammals. And all this diversity adapts to such harsh conditions, How:

• different salinity of water in Black Sea V different regions and depths (very few animals can withstand such changes);
• relatively low surface water temperatures for most of the calendar year;
• Hydrogen sulfide and the lack of oxygen at great depths are the main obstacle to the development of organic life in the form familiar on Earth.

One of the most interesting and fascinating phenomena on the Black Sea is its autumn “glow”. The reason for this is the unique pyridenea algae floating in the water. The names of the most common algae in Black Sea sound fabulous: Laurencia, Cystoseira or Coraline. Sea grapes and phyllophora live at depth. By the way, the reason for the glow Black Sea in autumn, not only in algae - some very small predators also glow - nightlights (noctilucas).

The dolphin is one of the main symbols of the entire Black Sea coast and many cities. And there are simply countless souvenirs with the image of this mammal sold at coastal markets. You can find out more about this amazing animal, as well as get to know the Black Sea dolphinariums in a special material "