Speaking of Lake Baikal, everyone should know! It is the largest freshwater lake in Asia and Europe, and also the deepest and largest lake in the world. The story of "suwu shepherd" in the Han Dynasty of China took place here. " The word 'Baikal' comes from the local Buryat language, which means' natural sea '. Its lake shape is long, narrow and curved, like a bright moon inlaid on the southern edge of Siberia. It is 636000 meters long, equivalent to the distance between Moscow and St. Petersburg, with an average width of 48, a maximum width of 79.4 and an area of 31500 square kilometers. So how did Lake Baikal come into being? What is the history of Lake Baikal?
The water of Baikal Lake comes from 336 large and small rivers of Selenge River, with extremely rich water. The lake flows out of the Angara river. The river is very fast. It is said that its wide index finger and bed pass quickly, running all the way north to the Yenisei River and finally into the Arctic Ocean.
There are 27 islands in Baikal Lake, the largest of which is orihon Island, with an area of about 730 square kilometers. The freezing period on the lake surface lasts for five months. The temperature on the lakeside is about 6 ℃ lower than that in the surrounding areas in summer and 11 ℃ higher in winter. It has the characteristics of marine climate.
Lake Baikal is clear, stable and transparent. It ranks second in the world, with a total water storage of 2360 cubic kilometers, equivalent to the total water storage of the Great Lakes of North America, accounting for about 1 / 5 of the global freshwater lake storage.
Baikal Lake is the oldest lake in the world. The bottom of the lake is sedimentary rock. The orogeny in the early Quaternary formed the mountains around the lake. The landform of the lake area has been basically formed for about 25 million years. There is a huge thermal anomaly zone under Baikal Lake, and volcanoes and earthquakes occur frequently. According to statistics, there are about 2000 large and small earthquakes in the lake area every year. Baikal Lake is surrounded by mountains, scattered streams, verdant primeval forest belts and beautiful scenery. Chekhov, the great Russian writer, wrote that "Baikal Lake is extremely beautiful". No wonder Siberians don't call it a lake, but a sea of. The lake is clear and transparent. Through the water, everything is as clear as through the air. The gentle green water is pleasing to the eye. The mountains on the shore are continuous and covered with forests, which is the immortal hymn of Lake Baikal.
In addition to the above, Lake Baikal has many unsolved mysteries. For example, the lake is not salty at all, that is to say, it is not connected with the ocean, but it lives with authentic marine organisms, such as seals, conch, sea fish and lobster.
For another example, there are tropical creatures in Baikal Lake. For example, its close relatives live in the lakes of India. Baikal leeches can only be seen in the freshwater lakes in southern China. The clams of Baikal only live in the oakreed Lake in the Balkans. What interests and puzzles scientists most is that there are many authentic marine organisms living in Baikal Lake, which is the difference of Baikal Lake. Among the freshwater lakes in the world, only Baikal has a dense 'jungle' - sponge at the bottom of Lake Baikal, and strange lobsters grow in the sponge.
However, people still don't understand that the water of Lake Baikal is not salty at all. Why do so many marine creatures live? Scientists have made various conjectures about this.
At first, some scientists believed that the geological Baikal Lake was connected with the sea, and marine life entered Baikal Lake from the ancient ocean.
Soviet scientist vileshagin believes that this is the result of crustal changes. Based on paleontological and geological materials, they speculated that there was a vast outer Baikal sea in the east of Baikal Lake in the Jurassic of Mesozoic. Later, due to crustal changes, Lake Baikal, an inland lake, was left. With the continuous addition of rain and river water, the salt water becomes lighter, and now the 'marine life' It was left over from that time.
In the early 1950s, people drilled several deep wells near Lake Baikal. However, from the core samples taken, nothing about the Mesozoic has been found. There are also some materials to prove it. There are no Mesozoic sedimentary strata, only Cenozoic sedimentary strata.
However, the geological research results show that the Baikal Lake area has been a land for a long time, and Baikal Lake is a fault lake formed in the crustal fault activity, which denies the statement that the marine life in the lake is a regressive species.