The Black Sea is an amazing work of nature that leaves no one indifferent to any researcher. It still harbors many mysteries in its depths. Many scientists today still dream of diving into its mysterious dark waters.
This sea covers an area of more than 400 thousand square kilometers and is located between Europe and Asia Minor. It appeared in the 6th millennium BC. due to a sudden and dramatic rise in the level of the world’s oceans, and before that it was just a large freshwater lake.
Bottom of the Black Sea
The seabed of the Black Sea in its relief looks like an upside down hat. The Black Sea has a fairly wide shallow water near the coast, which can be freely explored, and a deep, voluminous bottom in the middle, as yet little explored by scientists.
The largest shallow waters are located in the northwestern part of the sea, near Odessa and the surrounding resorts. And in the north and east of the Black Sea coast the explorer meets the mountains of the Caucasus and Crimea, hiding slopes deep under water.
How deep is the Black Sea?
Scientists have established that the maximum depth of the Black Sea is 2,250 m, and the average depth of the Black Sea is available for research – up to 1,300 m. Its inhabitants, whose life can actually be observed, settle no lower than 100 meters from the water surface.
Then the bottom of the Black Sea plunges sharply down to a depth of at least one kilometer, after which the uncharted deep water begins. The problem of his research is the presence of hydrogen sulfide in the water, which is dangerous to life and health.
Relief of the bottom of the Black Sea
The bottom shelf is a gentle slope under the water up to a depth of 100-150 meters. The shallow shelf zone includes the northwest of the sea. Then abruptly begins a continental almost steep cliff to a depth of more than a kilometer.
At the bottom of the Black Sea is sand or stony gravel. Even lower is the phaseolinic silt of the shelf. The thickness of the bottom silt, according to scientists, is 8-16 km, it is many times greater than the maximum depth of the sea itself. This is the structure of the ocean floor.
Where does the hydrogen sulfide come from?
Today there are several scientific hypotheses as to how hydrogen sulfide appeared in the sea, and why there is so much of it. Leading version: the bottom topography and features of currents contribute to the emergence and active life of anaerobic bacteria living without Q.
From the Bosporus into the Black Sea comes very salty, dense and cold water, which immediately settles, goes to great depths. Fresh and warm water comes from the rivers that feed it(Dnieper, Dniester, Danube, etc.), it accumulates to medium depths.
These two currents cannot mix with each other because have different water densities. Therefore, there is no oxygen in the denser, lower layers, and in its place is hydrogen sulfide produced by bacteria. The dead depths give the waters a dark color.
Hydrogen sulfide cannot reach the surface because between the two streams of upper living and lower dead water is a salt layer. If there is an earthquake deep below, the hydrogen sulfide rises, mixes with oxygen and explodes.
So it happened during the famous earthquake in the Crimea in 1927, when the water off the coast of the peninsula suddenly began to burn and felt the distinct smell of hydrogen sulfide.
Marine fauna and flora
At the boundary between the cold current and the warm current, at a depth of about 100-125 m you can see the remains of living organisms and shipwrecks. Together they present magnificent underwater museums – the delight of deep-sea diving specialists.
In recent years, several medieval warships and some other archaeological treasures have been discovered here. It is impossible to penetrate further than average depths, so the research is carried out with the help of special machines.
The living organisms and plants here are plankton, crayfish, jellyfish, crabs, sea fish, dolphins, numerous algae, etc. They breathe, develop and die. The remains of some organisms become food for other species of flora and fauna.
The most common local fish:
- mullet;
- anchovies;
- mackerel;
- horse mackerel;
- pikeperch;
- bream;
- herring;
- haddock;
- ruff, etc.
Due to the presence of hydrogen sulfide at depth and the lack of oxygen, deep-sea fauna is virtually absent here. There’s dead water running through there that can only harbor bacteria that don’t need oxygen.
