What? Can water from the Qinghai-Tibet Plateau flow to the Tianchi Lake in Changbai Mountain?

Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau is the largest plateau in China and the highest in the world, known as the "Roof of the World" and the "Third Pole". The water reserves of its lakes account for more than 70% of the country's total.

Changbai Mountain **** Tianchi

Changbai Mountain Tianchi is the highest volcanic lake in the world, with a total water storage capacity of 2.04 billion cubic meters.

Some scientists have discovered through observational data that the annual precipitation in the Tianchi Basin of Changbai Mountain is only 43 million cubic meters, while the annual overflow of water from the lake is an average of 123 million cubic meters, and 80 million tons of water are of unknown origin.

Image source: Photo Network

The Qinghai-Tibet Plateau is thousands of kilometers away from Changbai Mountain Tianchi, and there is no surface runoff, which seems to have nothing to do with it. However, Chen Jiansheng, a professor at the School of Earth Sciences and Engineering of Hohai University in my country, put forward a rather surprising view that most of the water in Changbai Mountain Tianchi comes from the Qinghai-Tibet Plateau.

In July this year, Chen Jiansheng from Hohai University and experts and scholars from West Lake University, University of California, and Swiss Federal Institute of Technology jointly published a paper in the internationally authoritative earth science journal Geology. The paper stated that after the underground river water in the Qiangtang Basin of the Qinghai-Tibet Plateau entered the rift valley, it flowed through water channels to the arid areas to the north and east of the Qinghai-Tibet Plateau, and part of it flowed into the Tianchi Lake in Changbai Mountain.

Image source: Sohu.com

Chen Jiansheng and others discovered through studying groundwater in the basalt layers that there are natural water channels in the basalt connected to the crater. These channels are gaps formed by the lava flow due to thermal expansion and contraction during the cooling process. Water from the ground seeps down and flows in the water channels. Under the action of gravitational equilibrium, groundwater at high altitudes will flow to low altitude areas.

The annual water volume of Changbai Mountain Tianchi is approximately 80 million cubic meters more than the precipitation. Although this amount of water is equivalent to six West Lakes, it is less than 1% of the infiltration water in the Qiangtang area of ​​Tibet.

Tibet Qiangtang Photo source: Baidu

Then the water on the Qinghai-Tibet Plateau

How did it flow to Changbai Mountain?

Schematic diagram of the connecting device of the basalt hole water channel by Chen Jiansheng

Researchers such as Chen Jiansheng believe that the seepage water from the Qinghai-Tibet Plateau enters the lava tunnel through the rift, flows in the closed water channel, and eventually leaks to the surface at the craters formed by the cooling of the lava flow and the gaps in the crustal rock fault zone.

Image source: Sohu.com

His team used this theory to drill deep water in the Badain Jaran Desert, and believed that one of the deep circulation groundwater flows from west to east along the suture zone between the plates, passing through Alxa, Ordos, the North China Plain and other areas directly to the Greater Khingan Range and Changbai Mountain in the northeast. The Tianchi Lake in Changbai Mountain itself is a crater, so one of the outlets in this channel flows into the Tianchi Lake in Changbai Mountain through the gaps after the lava flow cools.

The proposal of this theory has overturned our inherent thinking. Although the deep groundwater circulation theory supports that the water of Changbai Mountain Tianchi comes from the Qinghai-Tibet Plateau, further research and verification are needed to prove its rationality with more evidence.

Source: Science World

Producer: Ma Lian

Editor: Wu Nan

Tibet Science