"Black Sea", as its name implies, is named because it looks very dark. If you are lucky enough to sail on a yacht in the Black Sea, you will not see blue water, but black water. Why?

In fact, this is caused by the unique geographical location of the Black Sea. Although the sea area of the Black Sea is vast, its export is connected with the Mediterranean Sea in only one place, and that is the familiar Turkish Strait. The Turkish Strait is very narrow, with the narrowest point only 700 meters wide and the shallowest point only 33 meters deep. Such a narrow strait has hindered the exchange of seawater in the Black Sea, making it impossible to get a large number of exchanges in time.

Moreover, due to the injection of a large number of fresh water rivers such as Don River, Dnieper River and Danube River, the surface density of the Black Sea is small, but the deep seawater is affected by high salinity seawater, and the density is high. In this way, the density of seawater is small and large, which makes the seawater below 200 meters motionless, completely isolated from the outside world, and there is no sufficient oxygen supply at all. In the case of extreme hypoxia in seawater, sulfide bacteria in the water become active, decomposing a large number of organic substances on the seabed and forming hydrogen sulfide. Eventually, more and more hydrogen sulfide will dye the mud on the seabed black. The sea water we see is black.

However, if we scoop a spoonful of seawater on the sea surface, we find that the seawater is not black. This has also created a unique scene in which the Black Sea is not black in heart but black in face.