Why the Black Sea is not. Why the Black Sea is “black. How could hydrogen sulfide affect the name of the sea
At different times, the Black Sea had its own names. The Scythians called it Tana, the Iranians - Akhshaena, the ancient Greeks - Pont Aksinsky (Evksinsky). However, in the language of most peoples, the Black Sea has always been "black".
But does it have that color? After all, in clear weather, its waters are sky blue or greenish, in cloudy weather - purple, and at sunset - with a pinkish tint. Why is the sea called black? Where did such a name come from? There are several explanations for this.
Strabo's version
One of the most common is the version of the historian Strabo, according to which the Greek colonists called the Black Pond. Once, having arrived at its shores, they were unpleasantly struck by storms and squalls, as well as by the hostility of the Taurians and Scythians who lived here. Thanks to this, the Greeks gave the sea the name Pont Aksinsky, which means "Inhospitable Sea", or "black".
Later, when the colonists settled on the coast and became friends with the indigenous people, they renamed it Pontus Euxinus, or "Hospitable Sea". However, the first name has survived to this day. 
However, in the annals of Strabo one can find references to the fact that in ancient times the Black Sea was simply called the "sea", and in the X-XIV centuries, some Arabic and ancient Russian sources called it "Russian", which was associated with navigators traveling on the sea surface from Ancient Russia.
Sailors hypothesis
Like the Greeks, many sailors in antiquity called the Black Sea because of the storms that made it dark. This version cannot be considered reliable, since bad weather on the Black Sea is quite rare, and strong storms occur no more than 15–17 times a year.
In addition, a change in the color of sea water under adverse weather conditions is typical for many water bodies of the planet. There is an opinion that sailors could start from the characteristic black silt that accumulates on its coast after storms.
Turkish legend
According to the Turkish version, a heroic sword is hidden at the bottom of the Black Sea, which was thrown into the water at the last wish of the dying sorcerer Ali. The Turks believed that in an attempt to extract a deadly weapon from its depths, the sea waves and turns black. 
Another hypothesis is similar to the story of the Greek colonists. They say that once Turkish soldiers tried to conquer the population living on the coast, but they met desperate resistance and nicknamed the Kara-Dengiz sea - “black”.
Hydrologists version
An interesting version was put forward by hydrologists who studied the depths of the sea. In their opinion, the sea got its name due to the fact that metal objects (in particular, anchors) raised from its bottom turn out to be blackened. The reason for this lies in the large amount of hydrogen sulfide, which is saturated with water at depths below 150 meters. Getting on the metal, it covers it with a thin dark coating.
Large accumulations of hydrogen sulfide are associated with the small size of the Black Sea and the difficult exchange of water between it and the Atlantic Ocean. The insignificant magnitude of the tides and poor miscibility lead to the formation of two layers of sea water - the upper desalinated, containing a large amount of oxygen, and the lower, more salty and dense, poorly enriched with oxygen.
Hydrogen sulfide, formed in the deep layer, is a product of the vital activity of microorganisms, which over millions of years have accumulated millions of tons of colorless gas at the bottom.
Other versions
Some historians believe that the name of the sea is associated with the generally accepted color designation of the cardinal points in Asia. The north of the Asian peoples is black, hence the name of the reservoir located north of the Asian states. There is also a hypothesis that the sea was called Black by the Indian tribes (Sinds, Meots), who lived on the northern and eastern coast of the Sea of Azov long before the arrival of the Greek colonists. 
The Sea of \u200b\u200bAzov visually seemed to them lighter, so they gave the neighboring sea the name "black". Later, the Iranians settled in the habitat of the Meotians, who adopted a similar name, but renamed it in their own way - Akhshaena, or "dark".
On the world map you can find many "color" names - the Yellow Mountains in China, the Orange River in South Africa, the Blue Mountains in Australia, the Blue Volcano in Latin America, the White Sea in northern Russia, the Red Sea in the Middle East. The origin of the names of such a "palette" of objects is often explained by historical facts and geographical features, but sometimes beautiful legends arise around the names.
The question why the sea on the southern borders of Russia was called that way worried not only Russian travelers and researchers, but also foreign ones - after all, the sea also washes the shores of Georgia, Turkey, Bulgaria, Romania, and Ukraine.
The jagged turns blue in the darkness.
Alone I stand on a coastal cliff.
Far, wide, in expanse,
You lie before me, you Black Sea!
Like an azure canopy hanging over you
The boundless sky is blue.
Bathed in the sun like a mirror, smooth,
You seem to be sleeping so quietly, so sweetly.
I stand and admire your azure! -
Why do you think people are black?...
No, you wear a formidable name in vain,
You are black on a black day, on a clear day you are clear.
You're stormy, you're scary only when
A series of fights against the hurricane will come;
When, all dressed in thunder clouds,
He boldly breaks your mighty rest...
Mikhail Rosenheim, "Black Sea"
Today, more than 300 ancient names of the Black Sea are known. Some of them are associated with the peoples who lived in the region, or local states - the Cimmerian Sea, Scythian, Sarmatian, Colchis, Rumian, Thracian, Russian. Other names described its size - Great, Big, Deep - or geographical position: the North Sea was called by the Arabs who lived to the south, the East - by the Greeks and Romans. Color associations were also popular - however, not all ancient civilizations saw the sea "in black". There were variants of the names of the Dark Blue Sea and even the Red Sea.
In the 7th-6th centuries BC. e. The northern Black Sea region was mastered by Greek settlers. Because of unfamiliar places, unpredictable natural conditions and hostile coastal tribes, the Greeks began to call the sea "Pontos Akseinos", otherwise "Inhospitable Sea". They adopted this name from the ancient Iranian word "ahshayna", which meant "dark", "black". It is no coincidence that in ancient Greek myths and legends, Jason and the Argonauts, overcoming dangers, sail through this sea to Colchis for the Golden Fleece. And the "guilty" Prometheus was chained to a rock "at the end of the world" - across the sea, in the region of the Caucasus Mountains.
“... In those days, this sea was inaccessible for swimming and was called Aksinsky because of winter storms and the savagery of the surrounding tribes, especially the Scythians, since the latter sacrificed strangers, ate their meat, and used skulls instead of goblets. Subsequently, after the founding of cities on the coast by the Ionians, this sea was called "Euxine" ...
Greek historian and geographer Strabo, "Geography", 1st century BC. e.
However, when the Greeks settled in the new territory, the sea ceased to frighten them. It began to be called "Pontos Evkseynos" - "Hospitable Sea". And in the Russian chronicles later its name was transferred as the "Pontic Sea".
“The outlines of Pontus resemble a strongly curved Scythian bow. The sea is distinguished by its shallow depth, harsh temper, fogs, and steep, non-sandy shores. Bays are rare. Pontus washes the countries from which the north wind blows, and from the wind the sea is agitated and boils ... "
Roman geographer Pomponius Mela, "On the Position of the Earth", 1st century AD. e.
The title "Black" was finally fixed behind the sea already during the Turkic conquests in the XIII-XV centuries. The Turkish tribes raided the Black Sea region and met the fierce resistance of the local peoples there. Due to the coast full of dangers, the sea was nicknamed "Kara Deniz" - "Black Sea".
The Turkish legend about the hero who had a magic arrow is dedicated to the Black Sea. When she flew over the earth, she melted, and all living things withered. They launched an arrow over the water - and it boiled. The hero could not entrust the formidable weapon to his sons, so he hid the arrow in the sea. It boiled, seethed, wanting to throw the arrow out. That is why the calm waters became restless. It is believed that to this day the Black Sea is trying to get rid of this magical power.
There is another version of the origin of the name. Even the first sailors noticed how the water in the sea darkens during storms. And on the shore there was gray silt, blackening under the hot sun. The same sailors who anchored at a distance from the shore, got it darkened from a strange raid. Later, hydrologists studied the composition of the water in the Black Sea, and it turned out that its deep layers are saturated with hydrogen sulfide, in which all living things decompose. From this, a black coating appeared on metal objects, and the water column was seen by the ancient sailors as black.
Another name for the Black Sea sounds very ominous - "the sea of dead depths." Indeed, the waters of the Black Sea have unusual characteristics. The depths of the Black Sea are divided into two levels. Deeper than 150-200 meters there is practically no life due to the high percentage of hydrogen sulfide contained in the deep layers of water.
Over the years of its existence, the Black Sea has accumulated more than a billion tons of this substance, which is a product of the vital activity of bacteria.
According to one version, the very appearance of the Black Sea (7500 years ago) was associated with the mass death of the freshwater inhabitants of the Black Sea Lake, which was once here. From this, reserves of hydrogen sulfide and methane began to accumulate at its bottom. However, there is still no consensus on the origin of the huge amount of hydrogen sulfide in the waters of the Black Sea. The approximate amount of hydrogen sulfide in the Black Sea is 3.1 billion tons.
Recent studies also allow us to speak of the Black Sea as a giant reservoir of not only hydrogen sulfide, but also methane. It is the detonation of methane due to the movements of the lithospheric plates that today explains the strange phenomenon that occurred during the September 11, 1927 earthquake.
The well-known researcher of the Crimea, professor-geologist S.P. Popov described this phenomenon as follows: "... during the earthquake, observers of three lighthouses on the western coast of the Black Sea noticed a giant fiery band 55 kilometers from the coast over a long distance between Sevastopol and Cape Lukull." Subsequent interviews made it possible to establish that the fire was not a single one - three explosions were noticed by observers.
The sea attracts a person with its mystery and inaccessibility. Its inhabitants are often surrounded by a mystical halo, the human imagination places the most terrible monsters in the depths of the sea. The names are also surrounded by legends and myths. Why the Black Sea is called black, there is no exact answer. But there are a lot of interesting options presented by historians, geographers, hydrologists and sailors.
Legends and hypotheses about the appearance of the name
Such a variety of names, which were awarded to the sea by different peoples, should be proud of. No other body of water has received such an honor. It was named according to its geographical location and then paradoxical facts were obtained. For example, the Arabs called the North, and the Greeks called the East. The inhabitants of the coast made their contribution, bravely defending the villages from raids, for which he was nicknamed Kara-Dengiz, inhospitable.
Here are some guesses:
- The Black Sea legends colorfully describe some events, and one cannot help believing that a heroic sword or a golden arrow lies at the bottom, with which you can divide the world in half, so the sea rages and darkens, trying to throw a terrible weapon out of its depths.
- Another explanation why the Black Sea was called black lies in its wayward character. Storms, although rare, come on suddenly, causing the water to take on a dark hue. After that, piles of brown algae and dark gray silt remain on the shore.
- The next version belongs to hydrologists, who confirm the fact that the bulk of marine life does not fall below a depth of 100 m. Important: the reason lies in the hydrogen sulfide penetrating the lower layers. Bacteria reign there, feeding on the remains of dead animals and plants.
- Sailors say that a few hours before the storm, the water at depth darkens sharply.
- There are many reasons why the sea was called Black. Another version says that the name of the Black Sea was given by Magellan, who saw the open spaces raging during the storm.
When was the sea called the Black Sea for the first time?
Many, flying on an airplane over the surface of the water, note that they really look black and opaque. It immediately becomes clear why the Black Sea was so named. According to pictures from space, it also looks like a dark spot, so the name is quite justified.
Over the centuries, the sea has constantly changed its name depending on who spoke about it. There is no certainty about who came up with the idea to call the Black Sea. According to some sources, the origin was given by the translation of the Greek Pont Aksinsky, inhospitable, black.
There are many theories (and all, as one, plausible) about the origin of the name of the Black Sea.
Scientific and mysterious, historical and linguistic versions give this place a special charm.
Until now, scientists have not agreed on which of the hypotheses is most relevant, so you can prefer any one to your taste.
The French call it "Mer Noir", the Bulgarians - "Black Sea", the Turks - "Kara-Deniz", and all these names have "dark" roots.
But, arriving at the resort, tourists see only calm azure-turquoise waters and are actively surprised by such a gloomy name.
After all, there is no blackness - neither in the depths of the waters, nor in vegetation, nor on the surface - there is not a trace! And especially strong storms that can give the sea a tragic image have not happened here for a long time.
So, why is the Black Sea called black?
Version 1: The sea was harsh and inhospitable to sailors from Greece
The Greeks, who conquered the seas, were afraid of these waters like fire - storms often raged here, waves rose and ships were wrecked.
It was difficult to overcome the elements, so the "black place" was given a symbolic name - Pontos Akseinos (which literally means "inhospitable sea", "unkind").
Then, however, careless sailors nevertheless conquered the elements, and another, friendly and hospitable name was given to the sea - Euxeinos.
However, the former took root better and left an imprint in the coming centuries.
Version 2. Due to the shade of water
The Black Sea has quite ordinary water, which turns brown in February due to the influx of algae, and in spring and summer changes shades from gray-blue to greenish-blue.
However, from the height of the Caucasus Mountains, two whole seas are visible - the Azov and the Black. People watching from there saw the difference in the color of their waters.
The Azov looked bright, and the Black looked dark, so the Indian tribes began to call it Temarun.
The Scythians who replaced them also noticed the difference and named the sea Akhshaen (which translates only as “dark, gloomy”).
Even now, flying by plane, you will see that the Black Sea looks many times darker than the Mediterranean or Azov.
Version 3: Black silt is the reason for everything
In former times, strong storms raged on the Black Sea, the waters at that time darkened and frightened the sailors.
But the shock was even stronger the next morning - the entire coast was painted in black and gray tones due to silt thrown onto the pebbles.
Version 4: Scientific, "hydrogen sulfide"
Modern scientists know that in the depths of the Black Sea there is a real kingdom of hydrogen sulfide.
Pure water here is less than 10%, only a thin upper layer. The remaining 90% are so saturated with hydrogen sulfide that they cannot become a habitat for any flora and fauna. There are two conclusions from this fact.
Firstly, if you dive 150 meters down into the Black Sea, you will not find any life: these places are completely unsuitable for fish, algae and other inhabitants of water bodies.
Its depths are truly dark, empty and lifeless.
Secondly, any metal immersed in the abyss turns black - as the process of sulfur oxidation occurs. Sailors could not help but notice that their iron anchors take on a gloomy hue in these waters.
Version 5: Mystical about the gates of Hell 
The Black Sea has always been surrounded by fairy tales and legends. Either the princess threw herself into it with grief and drowned, and the waters, having accepted her, darkened from sadness.
Either the great prince hid a golden arrow in it, which had the power to destroy the whole world - having absorbed such power, any sea will turn black.
But the most mysterious theory is that at the depths there are hellish gates that hide the forces of evil.
She was born for a reason: more than once the ancient peoples had to observe a strange, as if fiery glow of these waters.
Today, scientists can easily explain that only one thing is connected with Lucifer - the substance luciferin.
It helps thousands of algae, poisonous jellyfish and microorganisms to glow in the dark. And these are various aurelias, cornerots, peridenes and noctilucs, inhabiting the local expanses in countless numbers.
Version 6: Translation error
Perhaps in Ancient Russia the sea was called “black”, that is, beautiful: its blue waters delighted the inexperienced eye.
Over time, the original meaning was lost, and the sea became simply “black”, mourning - after all, many ships sank in it.