The Caspian Lake is one of the most unique places on Earth. It keeps many secrets associated with the history of the development of our planet.
Physical Map Location
The Caspian is an internal drainage salt lake. The geographical location of the Caspian Lake is the continent of Eurasia at the junction of the parts of the world (Europe and Asia).
The length of the lake shore line is from 6500 km to 6700 km. Taking into account the islands, the length increases to 7000 km.
The coastal areas of the Caspian Lake are mostly low-lying. Their northern part is cut by the channels of the Volga and the Urals. The river delta is rich in islands. The surface of the water in these areas is covered with thickets. Waterlogging of large land areas is noted.
The eastern coast of the Caspian adjoins deserts and semi-deserts. On the shores of the lake there are significant deposits of limestone. The winding coastline is characteristic of the western and part of the eastern coast.
Caspian lake on the map is represented by significant size. The entire territory adjacent to it was called the Caspian.
Some characteristics
The Caspian Lake in its area and volume of water in it has no equal on Earth. It stretches from north to south for 1,049 kilometers, and its largest length from west to east is 435 kilometers.
If we take into account the depth of water bodies, their area and volume of water, then the lake is commensurate with the Yellow, Baltic and Black Seas. By the same parameters, the Caspian Sea surpasses the Tyrrhenian, Aegean, Adriatic and other seas.
The volume of water available in the Caspian Lake is 44% of the reserve of all lake waters of the planet.
Lake or sea?
Why is the Caspian lake called the sea? Is it really the impressive size of the reservoir that became the reason for the assignment of such a "status"? More precisely, this has become one of these reasons.
Others include a huge mass of water in the lake, the presence of ebbs and flows, a large wave during stormy winds. All this is characteristic of real seas. It becomes clear why the Caspian Lake is called the sea.
But one of the basic conditions that must exist in order for geographers to be able to rank the body of water in the sea is not mentioned here. It is a direct connection of the lake with the oceans. The Caspian does not meet this condition.
Where the Caspian Lake is located, several tens of thousands of years ago, a depression was formed in the earth's crust. Today it is filled with the waters of the Caspian. According to scientists, at the end of the 20th century, the water level in the Caspian Sea was 28 meters below sea level. The direct connection of the waters of the lake and the ocean ceased to exist about 6 millennia ago. The conclusion from the above is that the Caspian Sea is a lake.
There is another feature that distinguishes the Caspian from the sea - the salinity of the water in it is almost 3 times lower than the salinity of the oceans. The explanation for this is that about 130 large and small rivers carry fresh water to the Caspian Sea. The Volga makes the most significant contribution to this work - up to 80% of all water is "given" to the lake by it.
The river played another important role in the life of the Caspian. It will help to find the answer to the question of why the Caspian Lake is called the sea. Now that man has built many canals, it has become a fact that the Volga connects the lake with the oceans.
The history of the lake
The current appearance and geographical location of the Caspian Lake are due to continuous processes taking place on the surface of the Earth and in its bowels. There were times when the Caspian was connected with the Sea of Azov, and through it with the Mediterranean and the Black. That is, tens of thousands of years ago, the Caspian Lake was part of the World Ocean.
As a result of the processes associated with the raising and lowering of the earth's crust, mountains appeared on the site of the modern Caucasus. They isolated a body of water that was part of a vast ancient ocean. More than ten thousand years passed before the basins of the Black and Caspian seas divided. But for a long time, the connection between their waters was carried out through the strait, which was on the site of the Kumo-Manych depression.
Periodically, a narrow strait was sometimes drained, then again filled with water. This was due to fluctuations in sea level and changes in the appearance of the land.
In a word, the origin of the Caspian Lake is closely connected with the general history of the formation of the Earth's surface.
The lake got its modern name because of the Caspian tribes that inhabited the eastern parts of the Caucasus and the steppe zones of the Caspian territories. Over the entire history of the lake had 70 different names.
The territorial division of the lake-sea
The depth of the Caspian Lake in its various places is very different. Based on this, the entire water area of the lake-sea was conditionally divided into three parts: the North Caspian, the Middle and the South.
Shallow water is the northern part of the lake. The average depth of these places is 4.4 meters. The highest indicator is a mark of 27 meters. And at 20% of the entire area of the Northern Caspian, the depth is only about a meter. It is clear that this part of the lake is of little use for shipping.
The Middle Caspian has the greatest depth of 788 meters. The deepwater part occupies the southern water area of the lake. The average depth here is 345 meters, and the largest - 1026 meters.
Seasonal changes at sea
Due to the large length of the reservoir from north to south, climatic conditions on the coast of the lake are not the same. Seasonal changes in territories adjacent to the reservoir also depend on this.
In winter, on the southern shore of the lake in Iran, the water temperature does not drop below 13 degrees. In the same period, in the northern part of the lake off the coast of Russia, water has a temperature of no higher than 0 degrees. The North Caspian is icebound for 2-3 months a year.
In the summer, almost everywhere, the Caspian Lake warms up to 25-30 degrees. Warm water, excellent sandy beaches, sunny weather create excellent conditions for people to relax.
Caspian on the political map of the world
Five states are located on the shores of the Caspian Lake - Russia, Iran, Azerbaijan, Kazakhstan and Turkmenistan.
The territory of Russia belongs to the western regions of the North and Middle Caspian. Iran is located on the southern shores of the sea, it owns 15% of the entire coastline. The eastern coastline is shared by Kazakhstan and Turkmenistan. Azerbaijan is located in the southwestern territories of the Caspian region.
The issue of dividing the lake between the Caspian states has been the most acute for many years. The five heads of state are trying to find a solution that would satisfy everyone’s needs and requirements.
Natural wealth of the lake
Since ancient times, the Caspian has served as a water transport route for local residents.
The lake is famous for valuable fish species, in particular sturgeon. Their reserves account for up to 80% of world resources. The issue of preserving the sturgeon population is of international importance; it is being solved at the level of the government of the Caspian states.
The Caspian seal is another mystery of the unique sea-lake. Scientists still have not fully figured out the secret of the appearance of this animal in the waters of the Caspian Sea, as, incidentally, of other species of animals of the northern latitudes.
In total, 1809 species of various animal groups live in the Caspian Sea. There are 728 species of plants. Most of them are the "indigenous people" of the lake. But there is a small group of plants that were introduced here by man intentionally.
Of the minerals, the main wealth of the Caspian is oil and gas. Some information sources compare the oil reserves of the Caspian Lake deposits with Kuwait. Commercial offshore mining of black gold has been conducted on the lake since the end of the 19th century. The first well appeared on the Absheron shelf in 1820.
Today, the governments of the Caspian littoral states unanimously believe that the region cannot be regarded only as a source of oil and gas, while ignoring the ecology of the Caspian.
In addition to oil fields, in the Caspian region there are deposits of salt, stone, limestone, clay and sand. Their production also could not but affect the environmental situation in the region.
Sea level fluctuations
The water level in the Caspian Lake is not constant. This is evidenced by evidence relating to the IV century BC. The ancient Greeks who explored the sea discovered a large bay at the confluence of the Volga. The existence of a shallow strait between the Caspian Sea and the Sea of Azov was also discovered by them.
There are other data on the water level in the Caspian Lake. Facts indicate that the level was much lower than the current one. The evidence is provided by ancient architectural structures found on the seabed. The buildings date back to the 7th-13th centuries. Now the depth of their flooding is from 2 to 7 meters.
In 1930, the water level in the lake began to decline dramatically. The process went on for almost fifty years. This caused great concern among people, since all the economic activities of the Caspian Sea are adapted to the previously established water level.
Since 1978, the level began to rise again. Today it has become more than 2 meters higher. This is also an undesirable phenomenon for people living on the shores of a lake-sea.
The main reason influencing fluctuations in the water level in the lake is called climate change. This entails an increase in the volume of river water entering the Caspian, the amount of precipitation, and a decrease in the rate of water evaporation.
However, this cannot be said that this is the only opinion explaining the fluctuation of the water level in the Caspian Lake. There are others, no less believable.
Human activities and environmental issues
The catchment area of the Caspian Lake is 10 times larger than the surface of the water body of the reservoir itself. Therefore, all the changes taking place on such a vast territory in one way or another affect the ecology of the Caspian.
An important role in changing the environmental situation in the region of the Caspian Lake is played by human activity. For example, pollution of a reservoir with harmful and dangerous substances occurs along with the influx of fresh water. This is directly related to industrial production, mining of mineral resources and other human activities in the catchment area.
The state of the environment of the Caspian Sea and its adjacent territories is of general concern to the governments of the countries located here. Therefore, the discussion of measures aimed at preserving the unique lake, its flora and fauna, has become traditional.
Each state has an understanding that only through joint efforts can the ecology of the Caspian be improved.