Black Sea carbon dioxide. The Black Sea is a ticking time bomb

Over the past 60 years, almost 40% of the Black Sea area has become uninhabitable. This is the conclusion made by Belgian scientists from the University of Liege. According to experts, from 1955 to 2015, the depth of oxygen penetration decreased from 140 to 90 meters. At the same time, scientists discovered a deterioration in water quality associated with a large influx of phosphorus and nitrogen compounds into the sea.

That the water has become worse can be seen with the naked eye. Many vacationers complain that not only in Sochi, where the water has always been not very good, but in Abkhazia it is now dirty. Even on the beaches they warn that it is still possible to swim, but God forbid you take a sip of sea water - you can catch an infection. This, of course, upsets tourists: what kind of vacation at sea without diving?

Fishermen note a significant decrease in catch. Moreover, fishermen complain not only from Odessa and the Crimea, but also from Bulgaria and Georgia.

However, now it turns out that the Black Sea is threatened by much more serious danger than E. coli or a decline in fish populations.

“People watched in horror as the ashen sea began to seethe, boil, turn into a truly black one, as they called it God knows from what perelyaku, and began to disappear into some kind of funnel. It smelled disgustingly of hydrogen sulfide. The Black Sea ceased to exist ... Later, commenting on the incredible event, scientists came to the conclusion that few people always worried about the fatal role of hydrogen sulfide, which lies in a layer at a depth of forty meters, now it has escaped to the surface and “ate” the water. So the writer described the ecological catastrophe in the political novel "Nabat" Alexander Gera.

How can it really be?

It is known that the Black Sea has a depth of up to two thousand meters. But at a depth of more than 200 meters, only bacteria that produce hydrogen sulfide live. Fish and other organisms cannot live, since there is no oxygen there, there is only “dead water”, that is, a combination of hydrogen and sulfur. The surface layer is predominantly of river origin, the salt level there is quite low for the sea. At a depth of 50 to 100 meters, the salt content increases dramatically. The upper layers are much lighter than the lower ones, so they hardly mix.

Thus, the Black Sea is a deep reservoir with hydrogen sulfide and a thin layer of almost fresh water where all living organisms live. If this thin layer is threatened with extinction, then the entire sea can become not only lifeless, but also explosive.

A senior researcher at the Sevastopol branch of the State Oceanographic Institute named after N.N. Zubova Anatoly Ryabinin. He believes that a big catastrophe could threaten the Black Sea:

- According to our research, recent decades of the last century, the layer of hydrogen sulfide water really rose, sometimes to the level of 75 meters. In 1986, a special commission worked, it established that the danger of rising hydrogen sulfide waters remains.

"SP": - These studies have been carried out for a long time. What is the picture now?

- Unfortunately, all the information we have is only for the last century. In this century, we did not measure anything, we were not allocated money for research. In Soviet times, I was in charge of the laboratory of marine chemistry, so I was punished if by the end of the year I did not have time to spend all the funds allocated to the laboratory.

Our studies have shown that the level of hydrogen sulfide is increasing and we can expect emissions of hydrogen sulfide into the atmosphere during some cataclysms.

One simple fact can testify to the importance of the study of the Black Sea. Once a major of state security came to me and consulted. As he told me, the KGB had information that the Americans could lay a nuclear charge on the bottom of the sea and, in case of war, blow it up. We were then asked to evaluate the consequences of the explosion.

"SP": - And nothing can be done about this hydrogen sulfide scourge?

- At one time, the possibility of extracting hydrogen sulfide was studied in order to use it as fuel. Employees of the Moscow Research Institute of Oceanology. PP. Shirshov RAS always advocated not to extract more hydrogen sulfide than it is produced, as this can upset the natural balance. I have always taken a different point of view. In my opinion, hydrogen sulfide must be extracted in large quantities in order to clean up the sea over time, say, in a hundred years. Today, the Black Sea is the most dangerous on the planet.

"SP": - What are the consequences of raising the level of hydrogen sulfide?

— To the most catastrophic. In 1927, an earthquake occurred near Yalta. Then the sea literally burned. Some scientists believe that it was burning hydrogen sulfide.

If we talk about the factors that affect the level of danger, we can include natural and human impact. Today, objectively, the sea is polluted, this is a fact. I do not really believe in global warming, but it is difficult to say with complete certainty what consequences to expect.

In general, according to some scientific data, about 6000 years ago the Black Sea was clean, there was no hydrogen sulfide in it. For geology, this is a very short time. That is, the accumulation of hydrogen sulfide is rapidly.

A different point of view is shared by the head of the department of the Azov-Black Sea basin and the World Ocean of the Southern Research Institute of Fisheries and Oceanography (Kerch city) Vladislav Shlyakhov:

- In the Black Sea, there really is an extensive layer of hydrogen sulfide water, which is located at different depths in different parts sea, from 90 to 150 meters. The level of the hydrogen sulfide layer constantly pulsates, then rises, then decreases. It is not yet clear what data the Belgian scientists rely on. I personally do not see anything catastrophic in the change in the level of hydrogen sulfide.

There was a big noise back in the 1980s, when our institute, then employees of the Research Institute of Oceanology. Shirshov discovered an increase in the level of hydrogen sulfide. But further observations showed that this is a natural phenomenon. The rise is followed by a decline.

There is an opinion among some experts that sooner or later a catastrophe will happen. But in my opinion, there are normal fluctuations.

Over the past few years, the amount of precipitation has decreased, and accordingly, freshwater runoff has decreased. As a result, the level of hydrogen sulfide increased. All these processes have a large amplitude. Let's say that in the next years there will be more precipitation, and the freshwater layer will increase, hydrogen sulfide will decrease.

"SP": - How does it affect the process of changing the level of hydrogen sulfide global change climate?

- The climate is really changing, there is no reason to deny it. In the Black Sea, this is manifested in the fact that more warm winters lead to a change in the productivity of fish and other living organisms. But this has nothing to do with hydrogen sulfide. There will be more fresh water, and the level of hydrogen sulfide will decrease. There is a "locking layer" that prevents the penetration of hydrogen sulfide to the surface.

"SP": - How does economic activity affect the level of hydrogen sulfide?

— Economic activity will affect in one case. If the withdrawal of freshwater runoff increases. Let's say that water used to come to us through the North Crimean Canal from Ukraine. The flow of fresh water going to the Black Sea was decreasing. Because a lot water resources used for irrigation of fields and household needs. Now, flooding has begun near the Kakhovskaya hydroelectric power station in Ukraine, and Ukrainians are forced to dump excess water. Us more water they don't supply. As they say, neither to themselves nor to people. So, they throw excess water into the sea. Thus, the flow of fresh water into the sea has increased. In the northwestern part of the sea, even desalination is observed.

"SP": - The water in the sea has become dirtier, all sorts of infections have appeared.

- This is due to the abnormally warm summer. The sea began to warm up earlier, lasts longer heat water. Plus domestic and industrial drains. By the way, there are fewer effluents compared to Soviet times.

"SP": - Does climate change somehow affect the ecology of the Black Sea?

- This factor, of course, affects. And not only to the Black Sea - to all the seas. At global warming we may face much bigger problems than rising levels of hydrogen sulfide. We see that there is a melting of glaciers in Antarctica, near Greenland. The rise in the level of the World Ocean is much more dangerous, since the balance existing in nature can be disturbed.

But if we talk about a perspective commensurate with the lives of our children, then disasters should not come. However, my opinion is one of many.

But the clock is ticking...

Source: http://extreme-survival.io.ua/s206867/chernoe_more_bomba_zamedlennogo_deystviya

We so often look at the sky and are burning with an irresistible desire to unravel all its secrets that we do not notice at all something completely mysterious and unsolved right under our very noses. Lower your head and look at the sea. What do you know about him? About its sea depths and mysterious inhabitants? Everything and nothing at the same time. Neither the seas nor the oceans will be fully explored, not because they have great depth, but because they live a life parallel to us.

We won't go far. Take, for example, our native Black Sea. Rarely in the vastness of Russia and Ukraine you will meet a person who has never been to this sea. It seems familiar and familiar inside and out. But…

The Black Sea appeared on our planet by universal standards almost instantly, in just 8 thousand years, although nature had to work on such "ideas" much longer - more than a million years. But she managed quickly, and on the site of the New Evkiyskoye Lake-Sea, due to the movements of the earth's crust, the constantly changing climate and the level of the World Ocean, the Ancient Black Sea basin appeared.

By the way, it took on a modern look in just the last 3 thousand years. And the Black Sea is not some kind of puddle. Iceland, Portugal, Austria and Greece all together could easily fit on its territory. But this is just the beginning...
Back in 1927 In the Crimea there was a strong earthquake with a magnitude of 9 on the Richter scale. Its epicenter was only 25 km. from Yalta to the sea.

This earthquake claimed many lives and practically destroyed the city. But not only that it was remembered by the residents who survived the tragedy. While the city was shaking from monstrous tremors, the sea blazed with bright flames. It was not ships or port facilities that were on fire - it was the water itself that was on fire. Monstrous Phenomenon for a long time were kept secret. The Black Sea is far from being as safe as it seems at first glance. It turns out that it has a hydrogen sulfide layer - the main anomaly of the Black Sea. If someone does not know: hydrogen sulfide is a flammable substance that dissolves easily in water and explodes when mixed with air. In the Black Sea, it is found in waters at a depth of 125 m and occupies 90% of their volume. However, according to the latest studies of international expeditions, over the past 30 years, the level of the dangerous layer has risen by 50 m. And not so long ago, the hydrogen sulfide layer was discovered at a depth of only 30 m in southeastern parts of the sea. This suggests that not today, tomorrow the entire southeastern coast of the Black Sea can fly into the air in the truest sense of the word!

However, while hydrogen sulfide finally rises to the surface, another unique Black Sea layer - the Salt layer - does not give. It is he who gives life to the entire coast and protects people from death from the very creation of the sea. But do not relax.

Let's look at the stories that happened where hydrogen sulfide did come to the surface.

Cameroon

Visitors to a village near Lake Nyos found the entire population of the village dead. Dozens of bodies are forever frozen in the position in which they were overtaken by a poisonous cloud of deadly gases. In the area of ​​​​the killer lake in 1986. 1746 people died almost simultaneously.

Peru. 1980

Ships that went out to sea for fish came back black and almost empty. Instead of seaweed coastal waters Ah, there were tons of dead fish poisoned by hydrogen sulfide.

The Dead Sea. 1983

Its waters suddenly changed from blue to black. The sea seemed to be turned upside down and waters saturated with hydrogen sulfide came to the surface. This incident was recorded by an American satellite, which was making a revolution around the earth.
Scientists still have not figured out how and in what way hydrogen sulfide accumulates in the waters of the Black Sea and how it is spent. However, already in the late 70s, tons of dead fish were washed up on the shores of Odessa.

And although similar to the distant September elements, earthquakes happen once every 70-100 years, but you should not relax. The tension in the bowels of the planet increases year after year and earthquakes occur more and more often. If from 1949 to 1980. in the Crimea there were 6 medium earthquakes with a frequency of 5 years, then already since 1980. by 1998 their number increased to 7, but with a frequency of 2.6 years.

However, this is not all. A global catastrophe and, in the literal sense, a sea of ​​raging flames can be caused not only by natural disasters, but, first of all, by human life. Or rather, its waste. Every year, thousands, and even hundreds of thousands of tons of inorganic and organic substances, production wastes are dumped into the waters of the Black Sea basin. All together, this can turn into an explosive, the power of which could not be dreamed of by any tyrant who wants to take over the world.

We ourselves, with our own hands, are creating a time bomb, and if it detonates, Crimea and half the world will remain in our memories.

So, why not look at the stars so much, but pay attention to what is under our feet? It's still not too late.

And continuing on the topic:

The Black Sea, shining under the rays of the warm southern sun - what could be more beautiful? Huge, inviting, clean, transparent and incredibly beautiful ... Surely, these are the epithets that come to each of us at the mere thought of this sea - a source of inspiration for poets and a favorite vacation spot for many modern citizens. But few people know what is at the bottom amazing sea with the proud name Chernoye lurked a mortal danger - a lifeless abyss filled with poisonous, flammable, explosive gas with a disgusting smell of rotten eggs.

As a result of a large-scale oceanographic expedition, carried out back in 1890, it was found that about 90% of the volume of the sea is filled with hydrogen sulfide and only 10% is pure water that is not contaminated with poisonous gas. In the lower layer of the sea, neither animals nor plants are able to survive, but only certain types bacteria. A deadly gas fills a huge space, killing all life in its path. The entire volume of sea water is divided into two parts, surface water can reach the bottom of the sea only after hundreds of years. This property is unique, in the whole world there is not a single sea without a solid bottom.

The maximum depth of the Black Sea is just over two kilometers. The upper layer of water, where the life of marine life is concentrated, has a depth of only 100 meters, and in some places the thickness of the layer clean water hardly reaches 50 meters. Under it is a liquid lens of "dead" water, periodically breaking out and showing its destructive essence. Major breakthroughs are quite rare, but each of them brings a lot of harm to marine life. According to experts, the explosion of all hydrogen sulfide can be compared to the meeting of the Earth with an asteroid that has a mass half that of the Moon.

About the causes of the appearance of hydrogen sulfide.

Disputes over the cause of the appearance of hydrogen sulfide at the bottom of the Black Sea have not subsided so far. Poisonous gas could come from cracks in seabed or arise due to specific actions of bacteria. Without oxygen in the deep layers of the Black Sea, only anaerobic bacteria, which are involved in the decomposition of the remains of living organisms, can survive. As a result of this decomposition, hydrogen sulfide can be formed. According to another version, poisonous gas could be formed due to the specific communication of the sea with the oceans through the narrow Bosporus. A certain amount of water penetrates from the Mediterranean Sea into the Black Sea, turning it into a kind of sump, which has accumulated a large amount of hydrogen sulfide over many years.

Even 10 years ago, the issue of poisonous gas was considered one of the top priorities in the Black Sea countries, but today the hydrogen sulfide threat seems to have been completely forgotten. However, this problem has not disappeared and is not going to disappear. But how real is the danger? Perhaps everything is not so scary and hydrogen sulfide, hidden in the depths of the seabed, will remain there forever, without disturbing anyone? And what forces can contribute to the explosion of a huge amount of poisonous gas? These questions can be answered by the following reasoning.

The first reason for a possible explosion.

Imagine hypothetically that at the bottom Black Sea there was an explosion. Is it worth specifying what consequences will be experienced by marine organisms and inhabitants of coastal areas? At a minimum, the first ones will die, as a maximum - alas, both of them ... It sounds intimidating, but who needs to blow up the Black Sea? There are hardly any good reasons for this, even among the most notorious terrorists. But here is the time to remember what causes all the troubles on our planet? That's right - from human actions, often uncontrolled and irresponsible. One has only to wait for the moment when oil and gas companies will lay pipelines along the bottom of the Black Sea. The complexity of the repair and maintenance of such structures in an explosive environment will sooner or later lead to their failure and, as a result, to a large-scale explosion in the hydrogen sulfide layer. What will happen next is easy to guess. The Black Sea region can become a zone of ecological disaster, dangerous for people's lives. Innocent people will pay for someone's thoughtless actions and neglect of environmental safety issues.

The second reason for a possible explosion.

The cause of the explosion of hydrogen sulfide can be not only human irresponsibility, but also the vagaries of nature. The last such explosion occurred in 1927 during strong earthquake on the territory of Yalta. Two months before the incident, a phenomenon occurred that surprised local residents- local fishermen noticed a strange roughness of the water and a small swell, as if boiling for unknown reasons. A few minutes later, the eyewitnesses were deafened by an underwater roar - it was a "preparatory" push coming from the depths of the sea.
In the dead of night on September 12, 1927, the Crimean peninsula experienced the full power of an eight-magnitude earthquake. The epicenter was located near Yalta, but many other Crimean cities also suffered, serious damage to buildings and communications was recorded, crops died in the fields, and collapses and landslides occurred in the mountains.

But the most incredible phenomena occurred at sea. Eyewitnesses testified that the perturbations of the earth's crust were accompanied by a disgusting stench and flashes directed from the surface of the sea surface to the heavens. Pillars of fire, shrouded in smoke, reached several hundred meters in height. The Black Sea was burning, the same smell of rotten eggs was in the air. Lightning discharges hit precisely those places where hydrogen sulfide was concentrated. There were many versions about the reasons for this phenomenon, according to one of them, it was poisonous gas on the seabed that became the source of the explosion.
If the Crimean earthquake happened in our time, when hydrogen sulfide is under a thin film of water, everything would turn into a global catastrophe. Experts who are seriously puzzled by this problem paint a sad picture: an explosion of hydrogen sulfide in the Black Sea can lead to strong tectonic shifts and the release of a large amount of sulfuric acid into the atmosphere. acid rain, poisoned air, a series of earthquakes - that's what the population of coastal areas can expect.

The third reason for a possible explosion.

Hydrogen sulfide can explode for another reason. Over time, the top layer can simply become thinner, especially since in recent times there is a constant tendency towards a slow but sure emaciation of the layer of pure water. According to scientists, in a few years the thickness of the protective layer will be no more than 15 meters. All the fault will be anthropogenic pollution of sea water, which occurs regularly. Already, in some places, the presence of hydrogen sulfide is recorded at such a depth, but experts assure that the poisonous gas does not come from the bottom of the sea at all, but from the surface of the earth. Hydrogen sulfide, formed from fertilizers that have fallen into the sea, disappears during autumn storms.

Ways to solve the problem.

Experts say that the tragedy can be avoided, it is enough to act competently and in a coordinated manner for the benefit of the Black Sea. Scientists are not sitting idle - they already have some developments in stock, the main idea of ​​which is to use the Black Sea hydrogen sulfide as a fuel, because the poisonous gas releases a huge amount of heat during combustion. Sounds tempting, but how do you extract hydrogen sulfide from the seafloor? According to a group of scientists from Kherson, this is not difficult to do: it is enough to lower a strong pipe to a depth of about 80 meters and raise water through it once. Due to the pressure difference, a fountain is formed, consisting of gas and water. Simply put, an effect similar to opening a bottle of champagne will occur. In 1990, the authors of the idea made an experiment proving the possibility of such a fountain to work for a long period until hydrogen sulfide comes out.
Another method has also been developed for lifting hydrogen sulfide to the sea surface. Scientists proposed to pipe fresh water with a lower density than sea water. Several of these pipes, creating the effect of artificial aeration, would stop the spread of hydrogen sulfide and gradually completely eliminate it. Such manipulations are already being effectively carried out for cleaning aquariums and small ponds.

Similar developments, like many others in the countries of the former Soviet Union, remained unclaimed. People who have the opportunity to solve the problem turn a blind eye to it. I would like to hope that such self-confidence will not lead to sad consequences, and the Black Sea will remain for us all the same clean, transparent and incredibly beautiful.

Hydrogen sulfide(hydrogen sulfide, hydrogen sulfide) is a colorless gas with the smell of rotten eggs and a sweetish taste. Chemical formula- H 2 S. Poorly soluble in water, well - in ethanol. Poisonous. At high concentrations, it corrodes many metals. The concentration limits of ignition with air are 4.5 - 45% of hydrogen sulfide.

Very toxic. Inhalation of air with a low content of hydrogen sulfide causes dizziness, headache, nausea, and with a significant concentration leads to coma, convulsions, pulmonary edema and even death. At high concentrations, a single inhalation can cause instant death. At low concentrations, adaptation occurs rather quickly.

“The Black Sea does not receive 30 cubic kilometers of fresh water from the Dnieper, and another 40% of fresh water from other rivers,” Yakovenko said.

According to him, this leads to the fact that water that does not come from the Dnieper and other freshwater rivers, offset by the waters of the Mediterranean Sea.

“This water is heavier, due to minerals, and it acts in such a way that hydrogen sulfide masses rise from the bottom of the Black Sea,” the ecologist said. He added that if in the 1930s the level of hydrogen sulfide increased by 30 cm per year, now it rises to two meters per year.

According to Yakovenko, such a colossal rise in hydrogen sulfide could lead to an environmental disaster.

» — sea ​​of ​​hydrogen sulfide in the Black Sea. By the way, this phenomenon makes the Black Sea double by the sea, one inside the other. So to say, nested seas 🙂 Such nested seas are rare in nature. And the enclosed sea of ​​hydrogen sulfide is not found at all, except in the Black Sea.

The sea of ​​hydrogen sulfide in the Black Sea lies for a reason and does not touch anyone. If that were the case, then it would be quite possible that no one would ever know about it. But the sea of ​​hydrogen sulfide periodically manifests itself - and not everyone likes this manifestation. So, imagine a picture - you are relaxing in a resort. And you decide to get up early in the morning, look at the sea dawn. You dress up, go to the sea - and see something unimaginable! The entire coast is covered with fish, jellyfish, some kind of generally unseen animals. It's scary to approach. Corpses, corpses... And the smell of decay in the air.

But if you sit by the shore, look at this miracle, you will notice that Marine life on the shore occasionally move, twitch. And if you look even longer, you can see that they are gradually shifting back to the sea. And by eight or nine o'clock, when most of the vacationers go to the sea, the coast is already empty and no longer resembles a worldwide catastrophe.

What happened? There was a rather rare, but usual thing for the Black Sea - a small release of hydrogen sulfide. The smell of which you may have smelled.

Due to the fact that the upper layer of the Black Sea water is weakly mixed with the lower one, oxygen rarely reaches the sea bottom. And where there is no oxygen, decay begins there. One of the results of decay is the release hydrogen sulfide.

Well, since the upper, fresher layer of water rarely mixes with the lower, more salty one, this poisonous gas accumulates at the bottom of the Black Sea in huge quantities. And occasionally, when its amount exceeds conceivable limits, it comes out in the form of huge bubbles.

As the bubble passes through the upper, inhabited layer of the Black Sea, it poisons fish, jellyfish and other living creatures. And in an unconscious state they are taken ashore by the sea. Well, then, when they leave on land, the fish and shrimps run back to the sea.

Measurements showed that in the center of the Black Sea, the hydrogen sulfide zone approaches the surface by about 50 meters, closer to the coast, the depth from which the hydrogen sulfide sea begins increases to 300 meters. As we have already said, in this sense the Black Sea is unique, it the only sea in the world without a hard bottom.

Curious readers may ask: "Why does the gas, which is lighter than water, not immediately float up?" But this is who just belongs to the section "". Scientists believe that the pressure of the upper layers of water is to blame - 200 meters of water is no joke. And if at least part of this water disappeared, the Black Sea would boil from the hydrogen sulfide released in the form of gas.

Why do hydrogen sulfide emissions occur from the depths? For two reasons - an excessive increase in the content of this poison and underwater earthquakes. A small displacement of the earth's crust is enough, and the shock wave raises a huge gas bubble from the bottom of the sea. So, during the Crimean earthquake of 1927 in Yalta, residents watched the sea burn - hydrogen sulfide, which rose from below, interacted with the air and flared up.

Although, according to other sources, it was not hydrogen sulfide, but methane. And the concentration of hydrogen sulfide in water is so low that it cannot form gas bubbles, boil and poison animals. So it seems that there are no hydrogen sulfide bubbles ...

But it is up to scientists to determine what will happen if hydrogen sulfide decides to rise to the surface. We just need to know that there is not a single recorded case when hydrogen sulfide from the bottom of the Black Sea led to the death of people. Or even simple poisoning.

By the way, there is another question that has not yet been solved: “Why is it suddenly that there is a sea of ​​hydrogen sulfide in the Black Sea, but there is no sea of ​​hydrogen sulfide in other seas and oceans?” In fact, there are still disputes about the source of hydrogen sulfide in the depths of the Black Sea. Some consider the reduction of sulfates by sulfate-reducing bacteria during the decomposition of dead organic matter as the main source.

Although in this case another logical question arises: “Where in the Black Sea so many organic matter? To which there is no answer yet. But there is an interesting assumption: for example, one of the hypotheses for the emergence of the Black Sea says that 7500 years ago it was deepest freshwater lake on earth, the level was lower than the modern one by more than a hundred meters. At the end of the Ice Age, the level of the World Ocean rose and the Bosphorus Isthmus was broken through. A total of 100 thousand km² were flooded (the most fertile lands, already cultivated people). The flooding of these vast lands may have been the prototype of the myth of global flood. The emergence of the Black Sea, according to this hypothesis, was supposedly accompanied by the mass death of the entire freshwater living world of the lake (the same organics), the decomposition product of which - hydrogen sulfide - reaches high concentrations at the bottom of the sea

Other scientists adhere to the hydrothermal hypothesis, that is, the supply of hydrogen sulfide from cracks in the seabed as a result of volcanic activity. But even this version of the development of events does not explain why only the Black Sea was awarded such an honor - to be a double sea.

Partially, this distribution can be explained by the fact that the Black Sea is arranged in such a way that its water exchange with the Mediterranean Sea goes through the shallow Bosporus Threshold. Desalinated by river runoff goes to the Sea of ​​Marmara and further, and therefore lighter Black Sea water, and towards it, more precisely under it, through the Bosphorus threshold into the depths of the Black Sea, saltier and heavier Mediterranean water rolls down. It turns out something like a giant sump, in the depths of which hydrogen sulfide has gradually accumulated over the past six to seven thousand years.

Thus, the average concentration of hydrogen sulfide in the Black Sea is 5.73 mg/l at a depth of 1240 m, and the approximate amount of hydrogen sulfide in the Black Sea is 3.1 billion tons. Some Research recent years allow us to speak of the Black Sea as a giant 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

By the way, this hydrogen sulfide can not only harm or threaten. It can significantly help by improving the energy sector of the Black Sea countries. So, since hydrogen sulfide is a combustible gas, it can be burned - and due to this, energy can be obtained. Perhaps, economically, this is not very justified (although when there are thousands of tons of free fuel ...), but at the same time with an environmental result, this procedure could well help Ukraine with its lack of gas.

In order to clarify, one more detail needs to be clarified: when reading the article, it may seem that at the depth of the Black Sea there is not a solution of hydrogen sulfide in water, but a huge bubble of pure hydrogen sulfide gas, which, for unknown reasons, cannot float to the surface on its own and can explode ... In fact, things are simple there hydrosulphuric acid solution, i.e. there just mineral water. The same as in many hydrogen sulfide mineral springs that hit the surface and at the same time do not explode anything around.

So, as you can see, there are many opinions on this matter.

But, nevertheless, the sea of ​​hydrogen sulfide in the Black Sea is a mystery that has not yet been solved. But it shows up from time to time.

Based on materials http://voda.blox.ua/2008/07/Zagadka-Chernogo-morya.html

When in my distant childhood I read a poem by K.I. Chukovsky's "Confusion", I was most surprised by the pictures of the burning sea. It seemed like something really incredible, absurd. However, recently I learned that the sea can really catch fire, and the facts of its ignition are already known to history.

So, in 1927, when there was a major earthquake in the Crimea, fires in the Black Sea were recorded near Evpatoria and Sevastopol. However, then the fire at sea was caused by the release of methane - natural gas, the release of which from the bowels was provoked by an earthquake. The spectacle was amazing. Of course, this news was not advertised, but when journalists got their hands on information about those events in the 90s of the 20th century, the newspapers burst into sensationalism. The explosion in popularity of these articles was caused not so much by a methane release as by a distortion of facts: the newspapers wrote about the fire not of methane, but of hydrogen sulfide, after which it was concluded that a global catastrophe was possible.

There was something to be desperate about. Hydrogen sulfide, as you know, is a fairly stable combination of hydrogen and sulfur (decomposes only at a temperature of 500 degrees), a colorless poisonous gas with a pungent smell of rotten eggs. The hydrogen sulfide zone in the Black Sea was discovered in 1890 by N.I. Andrusov. Already then guessed about the large quantities of deposits of this gas. So, if you lower a metal load on a rope into the depths, then it will return completely black due to deposits of sulfites on it - salts that hydrogen sulfide forms with metals. (One of the hypotheses says that the Black Sea owes its name to this phenomenon).

However, at the beginning of the 20th century, it turned out that there is not just a lot of hydrogen sulfide in the Black Sea, but a lot - below a depth of 150-200 m, a continuous hydrogen sulfide zone begins. It is distributed, however, unevenly: near the coast, its upper boundary reaches 300 m, while in the center, hydrogen sulfide approaches a depth of about 100 m. The total amount of hydrogen sulfide dissolved in the Black Sea reaches 90%, so that all life is concentrated in a small surface layer, and there is no deep-sea fauna in the Black Sea.

Hydrogen sulfide is not some unique property only the Black Sea, it is found in soft remains at the bottom of all seas. The accumulation of this gas is due to the fact that oxygen practically does not penetrate into the water column and the processes of decay of organic residues prevail over oxidative processes. Sometimes hydrogen sulfide zones can form quite extensive accumulations. So, for example, the rift zone, discovered in 1977 in the zone of the underwater ridge Pacific Ocean, south of the Galapagos Islands, also contains hydrogen sulfide in large quantities; there are hydrogen sulfide zones in some deep closed bays.

One of the theories of the origin of hydrogen sulfide (the so-called "geological theory") suggests that hydrogen sulfide is released during underwater volcanic activity, and it can enter the seas through tectonic faults in the earth's crust. Hydrogen sulfide lakes in Kamchatka can serve as proof of this theory. Another theory - biological - says that we owe the production of hydrogen sulfide to bacteria, which, processing organic remains that have fallen to the bottom of the sea, form a substance from soil salts (sulphates), which, when combined with sea ​​water forms hydrogen sulfide.

However, one should not think that hydrogen sulfide is stored in the seas as Chemical substance in a warehouse, sealed in boxes. The sea is a constantly working biochemical laboratory. Thanks to the work of bacteria, plants and animals, some elements in the sea are constantly transformed into others. Ecological chains are formed in which a balance is maintained that determines the integrity of the entire structure. Bacteria play a huge role in the decomposition of organic remains into forms consumed by plants. Some bacteria can live without oxygen and light (anaerobic bacteria), others need sunlight to live, and others process organic compounds using both light and oxygen. Getting into different layers of the sea, organic matter enters the corresponding cycle of its processing and, ultimately, the cycle closes - the system returns to its original state.

Therefore, when the layers of the sea move (mixing), hydrogen sulfide is gradually converted into other compounds. In the Black Sea, water is mixed very weakly. The reason for this is the sharp changes in salinity, separating sea ​​water, as in a cocktail glass, into separate layers. The main reason for the appearance of such layers is the insufficient connection between the sea and the ocean. The Black Sea is connected to it by two narrow straits - the Bosphorus, leading to the Sea of ​​Marmara, and the Dardanelles, which maintains contact with the rather salty Mediterranean Sea. Such isolation leads to the fact that the salinity of the Black Sea does not exceed 16-18 ppm (a value equal to the salt content in human blood), while the salinity of normal ocean water should be in the range of 33-38 ppm (the Sea of ​​Marmara, having an intermediate salinity of about 26 ppm, acts as a kind of buffer that prevents the highly saline waters of the Mediterranean from flowing directly into the Black Sea). Salty water from the Sea of ​​Marmara, as a heavier one, when meeting with the waters of the Black Sea, it sinks to the bottom and enters its lower layers in the form of an undercurrent. In the area of ​​the boundary layer, there is not only a sharp change in salinity - "halocline", but also a sharp change in water density - "pinocline" and temperature - "thermocline" (deeper, denser layers of water always have a constant temperature - 8-9 degrees above zero) . Such heterogeneous layers make our sea cocktail a real layered cake, and, of course, it becomes very difficult to “mix” it. So, in order for water from the surface of the water to reach the bottom of the sea, hundreds of years are needed. All these factors lead to the fact that hydrogen sulfide, constantly accumulating in the depths of the Black Sea, gradually formed a vast lifeless zone.

Unfortunately, huge quantities of fertilizers and untreated sewage have been dumped into the sea lately, causing a glut. growth medium Black Sea. This was the reason for the rapid flowering of phytoplankton and the decrease in water transparency. Insufficiency of income solar energy necessary for the respiration of plants, led to the mass death of algae, and, along with them, many living beings. Underwater forests have been replaced by thickets of primitive, fast-growing sea ​​grass(filamentous and lamellar algae). Organic remains, not processed by bacteria, fall to the seabed in countless quantities. There is a mass death of flora and fauna.

In 2003, a unique accumulation of the red algae phyllophora (Zernov's phyllophora field), with an area of ​​11 thousand square meters, was completely destroyed. km., which occupied almost the entire part of the northwestern shelf of the Black Sea. This "green belt" of the sea produced about 2 million cubic meters. m of oxygen per day and, of course, with its destruction, the kingdom of hydrogen sulfide has lost one of its main competitors in the struggle for natural resources - oxygen that oxidizes it.

High rate of death of algae and seagrass, mass death living creatures, a decrease in the level of oxygen in the water - all these factors inexorably lead to the accumulation of a huge amount of decaying residues in the Black Sea and to an increase in the amount of hydrogen sulfide in the water.

So far, we are not afraid of hydrogen sulfide, since in order for the gas bubble to come to the surface, its concentration is needed, which is 1000 times higher than existing level. However, you should not relax. Too many factors speed up this process. Among them: the construction of breakwaters that reduce the speed of water circulation, work to deepen the seabed, laying oil pipelines, discharging fertilizers and sewage into the sea, and mining. Human activity is on such a scale that no ecosystem can withstand it. What threatens us?

Studying the archaeological layers, scientists have discovered the amazing fact of the almost instantaneous disappearance of the vast majority of life forms in the Permian period. One of the theories explaining such a catastrophe states that the massive death of fauna and flora was due to an explosion of a poisonous gas, presumably hydrogen sulfide, which could have been formed both due to numerous eruptions of underwater volcanoes, and as a result of the activity of hydrogen sulfide-producing bacteria. Research by Lee Kamp from the University of Pennsylvania, USA, showed that a decrease in the concentration of oxygen in the sea provokes an increased reproduction of bacteria that produce hydrogen sulfide. When a critical concentration is reached, this process can lead to the release of toxic gas into the atmosphere. Of course, it is too early to talk about any specific conclusions, the dynamics of changes in hydrogen sulfide levels is not exactly clear yet (it may take about 10 years to conduct a comprehensive analysis), but one cannot but feel a hidden threat in the facts presented. Nature has always been too patient with us. Can we expect salvation from her this time too?

Black Sea. It would seem so familiar and absolutely safe. Nothing like this. In its waters, not only poisonous marine life awaits you, but there is a more serious threat - suffocating poisonous fumes.

Dead zone

Not everyone knows that 90% of the Black Sea waters are saturated with hydrogen sulfide. This discovery was made back in 1890 by the Russian geologist Nikolai Andrusov. In some places, the hydrogen sulfide layer is located at a distance of 50 meters from the sea surface, and it constantly continues to strive upward. Periodically, a liquid lens of "dead" water approaches very close to the surface layers, which has a detrimental effect on the inhabitants of the underwater world.

However, there is still life in the hydrogen sulfide cloud, although in the absence of oxygen, only certain types of marine worms and anaerobic bacteria can exist here, which are involved in the decomposition of the remains of living organisms.

Hydrogen sulfide in water is not a unique phenomenon; it is also found in other seas and oceans. But given that the Black Sea is actually isolated from the World Ocean by the shallow Bosphorus and there is practically no normal water exchange, the concentration of hydrogen sulfide here is off scale.

Sometimes, as a result of storms, hydrogen sulfide vapors break out, and then in the gas outlet zone there is a specific smell of rotten eggs. This is extremely dangerous. If a large amount of hydrogen sulfide comes into contact with air, an explosion can occur. According to experts, the explosion of all hydrogen sulfide contained in the Black Sea can be compared with the consequences of the fall of an asteroid weighing half the mass of the moon.

But something like that already happened. In the dead of night September 12, 1927 Crimean peninsula experienced the full power of an 8-magnitude earthquake. The epicenter lay 25 kilometers south of Yalta, giant landslides were recorded, almost the entire crop died, many buildings were destroyed.

As eyewitnesses testified, earth's surface accompanied by a disgusting stench and flashes, soaring from the surface of the sea to the sky. Pillars of fire, shrouded in smoke, reached several hundred meters in height. So the Black Sea burned. Most scientists have no doubt that hydrogen sulfide was to blame.

Experts are seriously puzzled by the problem of hydrogen sulfide accumulating in the surface layers of the Black Sea. Any tectonic shift can lead to the release of a huge amount of toxic substances, and then the consequences can be much more serious than during the Crimean earthquake.

Oceanologist Alexander Gorodnitsky is convinced that such a threat is quite real: "The Black Sea is a seismically active region, there are earthquakes that provoke the release of gas hydrates - accumulations of methane and other combustible gases compressed under high pressure."

In an unfavorable scenario, tons of concentrated sulfuric acid will enter the atmosphere: thousands of people will die from suffocation, millions will have to move away from the coast, but even there they will be overtaken by hydrogen sulfide, spilling acid rain.

A few years ago, a hydrogen sulfide release was recorded at the Koblevo resort in the Nikolaev region (Ukraine). At that time, more than 100 tons of dead fish turned out to be on the shore. Engineer Gennady Bugrin, who participated in the aftermath of the disaster, warns that such an emergency could happen again at any time and on a larger scale.

Toxic water

Things are no better with environmental situation in the waters of the Black Sea, primarily because of the constantly incoming waste from the Danube, Prut and Dnieper. Industrial enterprises and public utilities without a twinge of conscience pour tons of production and human waste into rivers, which leads to the gradual extinction of many species of flora and fauna of the Black Sea coastal waters. Russia's most polluted maritime zone located in the area of ​​the ports of Novorossiysk and Taman.

Together with river water, pesticides, heavy metals, phosphorus, nitrogen enter the Black Sea, as a result of which phytoplankton rapidly reproduces and the water begins to bloom. And this leads to the destruction of bottom microorganisms, which in turn causes hypoxia and the subsequent death of many inhabitants of the seabed - squid, mussels, oysters, young sturgeon, crabs. According to environmentalists, the kill area sometimes exceeds 40 thousand square meters. km.

Of course, all this does not pass without a trace for a person. Head of the Department of Extreme Natural Phenomena and man-made disasters Oleg Stepanyan, Candidate of Biological Sciences, Oleg Stepanyan warns and reminds that the Black Sea is not a pool with filtered water and you need to choose the right places for swimming, because often even on city beaches you can see how sewage from nearby cafes and eateries is poured into the sea.

And although, according to Stepanyan, special services monitor the cleanliness of the beaches, the bacterial situation on them, it is important to be vigilant. Especially dangerous in such cases are sandy and pebbly beaches of large resort towns, where the process of self-purification of water is slowed down.

Deputy Coordinator public organization"Environmental Watch for North Caucasus» Dmitry Shevchenko notes that there are so polluted areas in the Black Sea, for example, in the Gelendzhik or Anapa bays that it is simply risky for health to enter the water.

Today, the massive development of green filamentous and lamellar algae, including the so-called sea lettuce (Ulva), has become a constant problem for the Black Sea. Eating such algae is fraught with serious poisoning, since they grow in places overcrowded organic matter coming through wastewater.

Doctors also warn about possible harm for the body of mussels and rapans caught in the large port waters of Novorossiysk, Tuapse, Sevastopol. Mussels actively filter poisoned sea water, and rapans are predators that eat them. But if, nevertheless, someone decides to feast on Black Sea delicacies, then one should pay attention to the color of their meat. Light yellow or pinkish indicates, most likely, its suitability for eating, but blue, black or just very bright indicates that the mollusks have accumulated heavy metals, oil hydrocarbons and other toxicants.

Dangerous inhabitants

In the waters of the Black Sea, of course, there is no such amount poisonous inhabitants, as in tropical seas, but still, extreme caution must be exercised here. First of all, we are talking about large jellyfish with a diameter exceeding 30 centimeters. In no case should they be touched, as you can get burned from stinging cells. A "kiss" of such a jellyfish in the throat or chest area can cause respiratory paralysis or heart failure.

In the sandy shallow waters of the Anapa bank, in the area from the village of Volna to the village of Blagoveshchensky, a stingray is often found, the poisonous spike of which can pierce even a thick rubber coating and inflict a very sensitive wound, followed by swelling of the damaged part of the body.

A small scorpion fish, or, as it is also called, sea ruff, is also a serious danger. She mainly hunts among the rocks, and hypothetically, she can be stepped on. A prick of its poisonous thorns will be very painful and it will take several weeks to heal the wound.

The sea dragon, although it does not look intimidating, carries no less of a threat than a stingray or scorpionfish. Poison glands are located on its first dorsal fin. Fishermen or divers sometimes inadvertently grab a thorn, and as a result, excruciating sharp pains in the wound area and a feverish state, accompanied by a rise in temperature. In this case, it will not be possible to do without a doctor.