Maximum depth Black Sea reaches 2.210 meters.
Depth varies
This can be judged, in particular, even by the resort city of Anapa, which has the status of an All-Russian health resort for family and children's recreation and treatment and one of the five resort areas of the Russian Black Sea region. And we know that in addition to Anapa, these zones also include Sochi, Gelendzhik, Tuapse, and since 2010, Taman, where the largest deposits of medicinal mud in Europe have been discovered, including in mud volcanoes, the number of which exceeds three dozen. The sixth resort area was the Crimean peninsula, which returned under the wing of its historical homeland.
So about the depth of the sea near Anapa and its resort villages. Starting from the Anapka river and towards Taman they go one after another to Dzhemete, Vityazevo, the village of Blagoveshchenskaya, not counting the smaller ones settlements like Vinogradny or the same Pyatikhatki, located near sandy beaches that stretch for as much as forty kilometers and even with dunes, like in the desert, overgrown with local olive trees and golden hills up to ten to twelve meters high. No other European state bordering the Black Sea region has such a priceless gold mine. And it was left as a souvenir to people by the ancient Kuban River, which previously flowed into the Black Sea and suddenly changed it and turned sharply towards the Sea of Azov. Happens here sometimes strong winds They constantly carry sand into the sea and therefore it is shallow near the mentioned resort villages and parts of Anapa itself. You have to walk a dozen meters from the shore for the water to come up to your head. And it is very safe for children and adults who cannot swim. But if in Anapa you go to the beaches of the High Bank, then be very careful and circumspect! There is no flat bottom - just depth! The same is true in other places of Big and Small Utrish or in the area of the same Sukko.
If you count to the maximum?
It turns out that the seabed from the surface is 2250 meters away. Can you imagine a depth of two and a quarter kilometers?! Alas, only 1,300 meters from the surface are suitable for scientists to study: deeper there is an environment that is lethal for humans and all living things - solid hydrogen sulfide, which occupies almost 90 percent of the volume of the entire reservoir, and is also explosive. And at a depth of two hundred meters only anaerobic bacteria can live.
Creation of the world ocean Tethys
It rolled its mighty waters during the Mesozoic era between 30 and 40 million years ago between the ancient continents of Gondwana and Laurasia. As a result of natural disasters, the mountains of the Caucasus and the Alps that emerged from its abyss fragmented it, including into one of the seas - the Sarmatian. In its place are now the Aral, Azov, Caspian and Black Seas. By the way, the world ocean Tethys is associated with the biblical flood. Especially when they find at the bottom of reservoirs oldest fossils their inhabitants. And not only the underwater world. So the modern Mediterranean, Black and Caspian seas are relics of the ancient world ocean Tethys. To clarify, the Black Sea is at the same time an inland sea of the Atlantic Ocean. The Bosphorus Strait connects with the Sea of Marmara, through the Dardanelles with the Aegean and Mediterranean seas, and through the Kerch Strait - with the Sea of Azov. Such is the geography! Let’s add to what has been said - the Crimean Peninsula cuts deep into the sea from the north. And the border between Europe and Asia runs along the surface of the sea.
Reservoir parameters
By human standards, the Black Sea is quite large. Some scientists are inclined to believe that its area is 422,000 square kilometers, but there are other researchers who raise this bar to 436,400 square kilometers. Over time, the truth will, of course, be established. We called the maximum depth 2250 meters. But the average is much less - 1300 meters. The volume of water in the reservoir is 555 thousand cubic meters. It is maximum 580 kilometers wide. There are statements by scientists that the Black Sea was formed 7500 years ago. As a result of rising sea levels. Before that it was a fresh lake. The bottom drops gradually. A depth of one hundred meters is observed a kilometer from the shores of Odessa, the resorts of the Caucasus and Crimea, then the bottom sharply drops to a depth of up to a kilometer, and then there is a deep-sea mountain basin. An explosive hydrogen sulfide environment occurs in some places after a depth of 120-125 meters. Some legends are associated with it. So, according to one of them, a certain wizard Ali hid his fiery sword in the waters of Tamariad. During strong earthquakes, its reflections make themselves felt. Two powerful earthquakes, for example, occurred in Crimea in 1927. June 26 and on the night of September 11-12. The strength of the tremors on the shore was more than six. The sea had been calm before. And suddenly a terrible roar was heard. The waters seemed to go wild. Moreover, hellish flames burst out of them, and in some places entire curtains of fire appeared. And, in particular, thirty kilometers west of Sevastopol. Flashes of fire were visible in Anapa, Evpatoria, and Sudak. According to scientists, methane emissions from the waters to the surface ignited. In addition, thunder rumbled and lightning flashed in the sky. Both people and all living things around were mortally afraid. And thank God that huge volumes of hydrogen sulfide are reliably hidden in the depths of the sea! By the way, this was not the only destructive earthquake with fiery whirlwinds over the abyss. The oldest dated back to 63 BC. Then it happened in 480 AD, which lasted for forty days and destroyed entire settlements on the shore. With the same curtains of fire and separate flashes of fire on the surface of the waters. Yes, the wizard Ali, even in the other world, with his sword hidden in the depths of the sea, does not give rest to everything in his vicinity!
Black Sea countries
There are seven of them - Russia, Turkey, Ukraine, Romania, Bulgaria, Georgia and Abkhazia. In other places, the bottom of the beaches drops gradually. In others it ends abruptly into the abyss. But the parameters of the maximum and average depths for them remain the same as we have given - 2550 and 1300. By the way, the Black Sea did not always bear its current name. The ancient Greeks said with trepidation that it was not hospitable, in their language - Pont Aksinsky. For the reason that its shores were inaccessible in places, and their inhabitants were cruel and warlike. And don’t let me, Zeus the Thunderer, end up at sea during a fierce storm. Everything around seemed black and black - both the sky above and the waters themselves. But as the coast was developed, trade and other connections were established with the tribes of the Caucasus who lived along the coast, the opinion of the descendants of the ancient Greeks changed categorically. The Black Sea received the name - Pont Euxine - the hospitable sea. But there were other names - in the tenth and fourteenth centuries - the Russian Sea. The Iranians and Scythians called the sea dark or in their language, respectively, Ashkhaena and Teng. The current name, the Black Sea, according to scientists, was given by the nomadic Turks Central Asia- Kara Denise, that’s how it sounded to them.
The entire coastline of the Black Sea exceeds 3,400 kilometers. From north to south it stretches, at its maximum, more than 580 kilometers. If we talk about the Russian Black Sea region, then it stretches from Adler to Taman for 1171 kilometers, plus another 750 kilometers of the coastline of the Crimean Peninsula. For the most part, the coast of our country is the Russian Riviera, the subtropics, in fact, a huge resort area. In which there are more than a thousand sanatoriums, boarding houses, and hotels. More than twenty million Russians themselves and guests from near and far abroad can relax and receive treatment there each year. The Black Sea is considered the warmest in our country. Average temperature water, for example, in February it is 6-8 degrees, and in August - 25. But in the summer it can be higher. You can swim in it, from May to October inclusive. And sometimes the summer Black Sea simply surprises vacationers. An angry north-west (northeast wind) blows in, and the water, which was above 25 degrees last night, suddenly becomes icy - 12-14 degrees. Holidaymakers simply shy away from her! But there is nothing surprising in this phenomenon: the wind blowing towards the sea drives warm water away from the shore, and in its place ice water rises from the depths. But a day or two passes and the water temperature rises to a comfortable level.
The depths of the sea are inexhaustible
For the simple reason that it is fed by the high-water rivers flowing into it - the Dniester, Southern Bug, Dnieper, Kuban (although it flows into the Sea of Azov, it is connected to the Black Kerch Strait), Reprua, Rioni. In addition, the Black Sea is also replenished by small rivers - Mzymta, Psou, Bzyb, Kodor, Enguri, Chorokh, Kyzylyrmak, Yeshilyrmak, Sakarya. The reservoir is fed by both rain and melting snow in the mountains. The sea is surrounded by large bays - Samsun, Sinop, Feodosia, Tendrovsky, Yagorlytsky, Dzharylgachsky, Karkinitsky, Kalamitsky, Varna, Burgas. By the way, there are few islands in the Black Sea. The largest is Dzharylgach - 62 square kilometers. Plus two more Berezin and Zmeiny with an area of a kilometer each.
Inhabitants of the deep sea
There are more than 190 species of fish in the Black Sea. 144 of them are marine. The rest are transitory and freshwater. The latter enter the sea from the rivers flowing into it. The annual catch of commercial fish exceeds 23 thousand tons. Sea rooster, anchovy, sprat, gobies, sprat, sprat, mullet, sawfish, bonito, bluefish, brown trout, herring - the list goes on and on. Some specimens of the inhabitants of the deep sea reach incredible sizes and are quite significant in weight. For example, a swordfish can exceed four meters and weigh half a ton. There are also flounder four meters long and weighing up to three hundred kilograms. Usually she is from seventy centimeters and weighs 17 kilograms. It is considered a delicacy; in the markets it costs from 700 rubles or more per kilogram. There are two types of sharks in the Black Sea - the katran and the cat shark. They do not pose a danger to humans. Katran fillet with the addition of lard makes delicious cutlets. It is better not to meet some types of deep-sea fish. For example, with a sea cow, which is covered in poisonous mucus. The big stingray, sea dragon and scorpionfish (ruff with poisonous spines) are dangerous. In the Black Sea there are Russian sturgeon, three species of dolphins - the white-sided dolphin, the bottlenose dolphin and the common porpoise, and the monk seal.
Connected not only with Ali’s magic sword hidden in its depths. During strong and destructive earthquakes, they send bright curtains and flashes of hydrogen sulfide fire to the surface. The first information about the Black Sea appeared in the fifth century BC. And even then there was a rumor about the journey of the brave captain Jason to Colchis for the Golden Fleece on the famous “Argo”. Residents of Anapa stubbornly insist that the courageous sailors sailed past the high and inaccessible rocks of the current resort village of Bolshoi Utrish, with which another legend is associated - to one of the rocks of Bolshoi Utrish, by the will of Zeus the Thunderer, the hero Prometheus, who gave people sacred fire Olympus. And every morning an evil eagle flew to the martyr to torment his liver. True, the legend is disputed by Sochi residents. Like, Prometheus was chained to one of the Eagle Rocks near their resort. And they even erected a monument to the hero - the mighty Prometheus stands with the chains torn on his hands and proudly looks into the bottomless sky! As if threatening him for the suffering he endured. But here's the catch. Eagle Rocks are located far from the sea. In addition, recently in an excavation in the very center of Anapa, otherwise it is called a museum under open air“Gorgippia” ( ancient name resort city), they found a crypt with frescoes about the exploits of another hero of Hellas, Hercules, and he, according to ancient Greek mythology, freed Prometheus from chains and the bloodthirsty eagle. The future will show who is right and who is wrong. And residents of the Black Sea countries, including Russia, cannot stop admiring their vast and deep sea- different every time: sometimes quiet and calm under the blue sky and bright sun, sometimes furiously raging when the sky merges with the earth and it really becomes blacker than black!
This sea is perhaps closest to us. It was once called “Russian” - these are echoes of Soviet times, when the Black Sea was the most “popular”. Today the sea washes the shores of seven countries: Russia, Ukraine, Bulgaria, Romania, Turkey, Georgia and Abkhazia.
Hospitable or inhospitable?
The Black Sea had a huge number of names. The very first one that has survived to this day was given to him by the ancient Greeks. By the way, it was along the Black Sea that Jason and the Argonauts set sail for the Golden Fleece.
The Greeks nicknamed it Pont Aksinsky, which means “inhospitable sea.” And all because it was not so easy to approach it: the shores of the Black Sea in those days were inhabited by warring tribes, zealously guarding the territory. And navigating the pond was quite difficult. Later, after the conquest and development of its coast, the sea became “hospitable” or Pontus Evsinsky. In addition, his other names are known: Temarun, Akhshaena, Cimmerian, Blue, Ocean, Tauride, Holy, Surozh. Well, in Rus' the Black Sea was called “Scythian” or “Russian” from the 10th to the 16th centuries.
Why black
In fact, there is no exact explanation why the reservoir was nicknamed “black”. There are at least two versions of the origin.
In the old days, parts of the world were designated by colors: black meant the North, and white meant the South. According to this theory, the body of water located in the north was called the “Black Sea”. By the way, the Mediterranean Sea in Turkish known as the "White Sea", that is, the sea that is located in the south.
Well, the second version says that the reservoir received its name because of the abundance of hydrogen sulfide in its depths, which has an unusual property. The fact is that any metal object (for example, an anchor) when lowered into deep water (more than 150 meters) becomes covered with a black coating for a long time.
The currents have an unusual shape
The pattern of the Black Sea currents is unusual: these are two looped whirlpools, reminiscent of glasses. True, they are gigantic: their wavelength reaches about 300-400 kilometers. By the way, they are called Knipovich glasses in honor of the oceanologist who first described them.
About the sea depths of the Black Sea
The maximum depth of the Black Sea is 2210 meters. The average depth is 1240 meters. The deepest places (and not only the deepest in fact) have their own peculiarity: there is no life here. For this feature, the reservoir even received another name, an ominous one - “the sea of dead depths.”
The thing is that once upon a time there was a freshwater lake on the site of the Black Sea. True, a very long time ago: about 7500 years ago. Freshwater inhabitants lived in it. And it was the deepest freshwater lake on Earth.
But then cataclysms occurred: perhaps, due to the Ice Age, the level of the world's oceans rose significantly, flooding the lake and turning it into a sea (the reservoir increased by about one and a half times!), or an earthquake contributed to the water breakthrough. Or maybe both happened at once? natural disasters. Because of this, many freshwater inhabitants died, contaminating the waters with hydrogen sulfide. And hydrogen sulfide is nothing more than a product of the vital activity of bacteria, or rather, a product of the decomposition of the remains of animal organisms.
Well, we see the result today: at a depth of more than 150-200 meters in the Black Sea there is practically no life. There are only bacteria here.
By the way, perhaps this tragedy served as the basis for the Great Flood. After all, it was widespread locally, especially among the peoples of the Middle East.
Sharks that can cure cancer
Despite the contamination with hydrogen sulfide, the Black Sea has its own inhabitants, and very interesting ones.
So, there are harmless katrana sharks here. They are small, do not exceed a meter in length, and do not pose a danger to vacationers: they practically do not approach the shore and live mainly in cold waters, and they are afraid of people.
However, they may pose some threat to fishermen. The fact is that on their dorsal fin there are large spines that can cause injury.
Catran sharks are also used in pharmacology. Their fat has healing properties, and a substance found in their liver can cure some forms of cancer. Therefore, on its basis, a drug to combat tumors, Katrex, was developed.
Other inhabitants of the Black Sea
In addition to small sharks, the Black Sea is home to approximately 2,500 species of animals. But this is very small: for example, in the Mediterranean there are about 9 thousand species of animals.
The most dangerous of the Black Sea inhabitants is the large sea dragon or sea dragon. It has poisonous spines on its dorsal fin. And this is the most poisonous fish, which lives off the coast of Europe. The dragonet's bite is very painful, and several deaths have even been reported. But besides him, there are two more dangerous inhabitants: the Black Sea scorpionfish and the stingray.
Of the mammals in the Black Sea, two species of dolphins live, the white-bellied seal and the porpoise. Some animals enter the reservoir through the Bosphorus Strait.
Well, among the algae there are very unusual look- sea candle. This algae is capable of bioluminescence: their accumulation at the surface of the water causes an interesting phenomenon - the glow of the sea. It can be observed in August.
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. The reasons for this unusual phenomenon are as follows:
In the Black Sea, due to its desalination by rivers, there are two masses, two layers of water that weakly mix with each other.
Surface layer black sea water- to a depth of approximately 100 meters - mainly 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 sharp changes in the 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. Bacterial decomposition of 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 the sea (where it does not penetrate sunlight), under the cold intermediate layer - below a depth of 100 meters, 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, there are no predatory fish of the deep 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 the sun-warmed surface water in which people swim and the 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:
Considering relief the Black Sea bottom, we can distinguish:
- shelf;
- extended continental slope;
- deep basin.
The widest part of the shelf (about 200 km) is located in the north-west of the Black Sea. The thickness of the water layer here is 110 – 160 meters. The depth of water above the shelf in other places of the sea is less and, as a rule, does not exceed 110 m. The width is from 10 to 15 km (off the Turkish coast - 2.5 km).
The continental slope is heterogeneous, strongly dissected by submarine valleys and canyons. Its steepness in some areas reaches 20-30°. From Sinop to Samsun, a system of deep ridges stretches almost parallel to the coast. Their total length is about 150 km. The bottom of the basin is an accumulative plain, flatly deepening towards the center up to 2000 m. Maximum depth of the Black Sea– 2211 m.
The seabed consists of parts of different ages and geologically heterogeneous. The larger portion of the basin is located in the Alpine geosynclinal region. The earth's crust underneath consists of many layers, which can be divided into “sedimentary” and “basaltic”. The sedimentary layers are about 16 km thick, with their upper, 4 km, part located horizontally. In the central part of the basin, the density of the earth's crust reaches 25 km. Along the periphery, the basalt layer is hidden under a 35-kilometer granite layer. The northwestern section of the Black Sea shelf covers the EpiPaleozoic Scythian platform and the south of the East European platform.
Coastal zone Black Sea- These are coarse sediments such as pebbles, gravels and sands. Moving away from the coast, these deposits are replaced by silts and fine-grained sands. In the northwestern region of Cherny the sea is coming abundant formation of shell rock and jars inhabited by oysters, mussels and other shellfish.
In the Black Sea there are deposits of minerals - oil and gas. Their main reserves are concentrated in the northwestern part of the basin. In addition, the coastal zones of Taman and the Caucasus boast placers of titanomagnetite sands.
The territory of the modern Black Sea has a complex geological past. Scientists today still discover traces of certain natural disasters under calm sea waves.
Forty million years ago, at the beginning of the Tertiary period, Asia and southern Europe were the bottom huge ocean basin, called the Tethys Sea. With a giant canal, this sea connected the Atlantic Ocean with the Pacific Ocean. In the middle of the Tertiary period, movements of the earth's crust separated Tethys from Pacific Ocean, and then from the Atlantic.
Active mountain-building movements in Eurasia began about seven million years ago, during the Miocene period. Over four million years they formed Carpathians, Alps, Balkans and the Caucasus Mountains. The area of the Tethys Sea decreased, and separate basins formed from it. One of these basins was the Sarmatian Sea, stretching from the foothills of the Tien Shan to modern Vienna.
At the beginning of the Pliocene period (1.5 - 3 million years ago), the Sarmatian Sea decreased in size, first becoming salty Meotic sea, and later - the almost fresh Pontic lake-sea. One million years ago, the size of this lake was comparable to the size of Lake Chaudin.
About 500 thousand years ago, the Mindelian glaciation ended. The glaciers began to melt. Their waters flowed in streams into Lake Chauda, filling it and turning it into Ancient Euxinian basin. Its area was close to that of the modern Black Sea.
150 thousand years ago, the Karangata Sea was formed from the Ancient Euxinian basin. The salinity of the water in it was much higher than the salinity of the water in the Black Sea today.
20 thousand years ago, the Karangat Sea slowly “turned” into the New Euxinian Sea. Its appearance coincided with the end of the last Würm glaciation. The transformation of the Novoeksinsky Sea lasted 10 thousand years, after which a new one began, modern stage life of the Black Sea. And at this stage, we, people, are actively helping nature to “accelerate” the course of Black Sea history...
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Format C-MAP cards MAX-N+ provide accurate and updated information, unique characteristics, as well as specialized data to increase awareness.
MAX-N format maps, in turn, have precise detail and provide data not only on depth zones and contours, depth measurements, navigation information, light sectors, wreck and impassability zones, and anchorage areas. As well as small fleet maintenance equipment and much more.
C-MAP MAX-N cards are compatible with Lowrance Elite-9 CHIRP, Elite-7,5,4 HDI and CHIRP, Mark-4 HDI and CHIRP, as well as Lowrance HDS® Gen2 and HDS® Gen2 Touch, HDS® Gen3 series , HDS CARBON, HOOK, Elite TI.
