Black Sea

The Black Sea is a sea in Eurasia between Europe, Caucasus, and Anatolia. Many important rivers flow to the Black Sea, including the Don, the Danube, the Dniester and the Dnieper.

It is connected to the Atlantic Ocean through the Bosphorus, the Sea of Marmara, the Dardanelles, the Aegean Sea, the Mediterranean Sea and the Strait of Gibraltar. The sea is divided by Crimea. 

Nine tenths of the Black Sea has no oxygen. Its water is saltwater but less salty than the oceans are. During the last ice age, the Black Sea was a freshwater lake. 

 History 
In Greek mythology, the Argonauts traveled on the sea. The ancient Greeks set up colonies around the sea because it was important for them to trade during ancient history. The Gallipoli Campaign. during World War I. was a fight for access to the Black Sea, which was also an important sea during World War II.

 Hypothesis 

One theory suggests the Black Sea was once a freshwater lake 7,600 years ago c. 5600 BCE. I Later, the Mediterranean Sea’s water rose and breached a rocky sill in the Bosporus and flooded the lake, transforming the so-called “Black Lake” into a brackish inland sea.  The event flooded 100,000 km2(39,000 sq mi) of land and significantly expanded the Black Sea shoreline to the north and west.  This was proposed by William Ryan, Walter Pitman, Petko Dimitrov, and their colleagues.

 Geology 
The Black Sea sits on continental plates, which have subsided. It is a geologic basin and so is a genuine inland sea. It has a maximum depth of about 2000 m. The Black Sea is the world’s largest basin, and its deep waters do not mix with the upper layers of water that receive oxygen from the atmosphere. As a result, over nine tenths of the deeper Black Sea volume lacks oxygen.

The upper layers of the Black Sea are fed by large river systems and so are generally cooler, less dense and less salty than its deeper waters, which come from the warm, salty waters of the Mediterranean Sea.

Crimea is a peninsula that divides the Black Sea. The Bosporus and the Dardanelles connect the sea to the Mediterranean.

 References 

Category:Black Sea