The Black Sea is located in the interior of eurasia, is the boundary between Asia and Europe, although the Black Sea is an ocean, but it is very far from the ocean, it can be said to be deep inland. The area of the Black Sea is about 424,000 square kilometers, which is slightly smaller than the area of Gansu Province in China, and the countries along the Black Sea coast include Ukraine, Russia, Georgia, Romania, Bulgaria and Turkey.
The Black Sea was once a "Black Lake"
The Black Sea is only connected to the Mediterranean Sea by the Turkish Strait in the southwest (consisting of the Dardanelles, the Marmara Sea and the Bosphorus), and the sea waters are exchanged very slowly. Due to the relative closure of the Black Sea and the influx of fresh water from the surrounding rivers, the salinity of the Black Sea is lower than that of the Mediterranean Sea, and there is a phenomenon of density flow in the Turkish Strait. That is to say, the surface 10 to 20 meters of sea water flows from the Black Sea into the Mediterranean Sea, while the bottom sea flows from the Mediterranean Sea to the Black Sea.
Turkish Straits
The Black Sea, including the surrounding Caspian Sea and the Mediterranean Sea, was once part of the Ancient Mediterranean Sea, a remnant basin of the Ancient Mediterranean Sea, with an average current water depth of 1315 meters and a maximum depth of 2210 meters. The uplift in Asia Minor at the end of the Paleocene between 65 million and 55 million years ago separated the Black Sea from the Mediterranean Sea, and the Black Sea gradually became an "inland sea", but in fact, due to the influence of crustal movement and ice age, there were many repeated isolations and connections between the Black Sea and the Mediterranean Sea, that is, sometimes it was the "Black Sea" and sometimes the "Black Lake".
Black Sea
The Quaternary Ice Age is the most recent Great Ice Age, beginning at the beginning of the Quaternary Period, about 2 million to 3 million years ago, and ending about 10,000 to 20,000 years ago, a very large ice age. During the Quaternary glacial period, the global average temperature was low, and there was a large area of glacier cover in the middle and high latitudes, and because a large amount of water existed in the form of solid state, the sea level at that time was 100 to 200 meters lower than it is now.
Global glacier cover during the Quaternary glacial period
During the Quaternary glacial period, when the Black Sea and the Mediterranean Sea were separated from each other, that is, the "Black Lake" at that time, and the sea level in the Black Sea area at that time was much lower than it is now. About 8,000 to 10,000 years ago, in the plains of the Black Sea coast, it was a relatively densely populated area, with very developed agricultural production and settlements. Now, archaeologists have found the ruins of Neolithic settlements on the seabed 24 kilometers from Turkey, which were built at that time, and these settlements are currently lying quietly on the bottom of the Black Sea at a depth of 100 meters.
Black Sea coastal area
In fact, the Black Sea coastal region was the first region in West Asia and Europe to carry out agricultural production, and these farmers lived happily here for many years. Until about 7600 years ago, with the end of the ice age, the glaciers continued to melt, the sea level of the Mediterranean Sea also continued to rise, the sea water passed through the Turkish Strait, into the Black Lake Basin, the lake water rose at a rate of about 15 centimeters per day, the lake water soon flooded the fields and villages, and eventually became today's Black Sea. Local farmers, forced to migrate to other areas, may be the "Great Flood" recorded in the Western Bible.
Bosphorus Bridge