34mm per year! The tallest tree in our country is still moving...

According to the Forestry and Grassland Bureau of Medog County, Tibet, through cooperation with a scientific research team led by Peking University, a 76.8-meter-tall Bhutan pine was recorded in Green Village, Beibeng Township, Medog County, breaking the previous record of the 72-meter Taiwania baldii tree king located in Gaoligong Mountain in Yunnan. It is currently the tallest known tree in China and has become the veritable new "Tree King".

Medog County is located in the southeastern part of the Tibet Autonomous Region, in the middle and lower reaches of the Yarlung Zangbo River. Its average altitude is about 1,200 meters, which makes Medog County an oxygen bar on the Qinghai-Tibet Plateau, whose average altitude is 4,000 meters.

But do you know? The land under the feet of the new "Tree King" is still moving at a rate of 28 to 34 mm per year...

1. Origin: The Roof of the World under Plate Collision

About 60 to 55 million years ago, with the extinction of dinosaurs, the Cenozoic Era began, with the continents and oceans growing and shrinking. After drifting for 2,000 to 3,000 kilometers, the Indian Plate collided head-on with the Eurasian Plate, causing a strong uplift of the earth's crust, forming the present-day Qinghai-Tibet Plateau.

2. Formation: Millions of Years of Continuous Movement

The Qinghai-Tibet Plateau has never been quiet since its formation. Until now, the Qinghai-Tibet Plateau has been expanding into the interior of the continent. Over the past million years, new basins and mountain ranges have been continuously formed on the northeastern edge of the Qinghai-Tibet Plateau. The formation, evolution and extinction of basins and mountain ranges in the northeastern Qinghai-Tibet Plateau were finally confirmed by researchers who collected thousands of continuous magnetic stratigraphic samples in the basins and collected low-temperature thermochronological samples of rocks at different altitudes in the mountains through laboratory analysis of these samples.

The northeastern edge of the Qinghai-Tibet Plateau is the tectonic position of the Qinghai-Tibet Plateau. The Qilian Mountains are located on the northeastern edge of the Qinghai-Tibet Plateau. It is the forefront of the expansion of the Qinghai-Tibet Plateau to the northeast. In the early days, the Qilian Mountains were a very low and gentle mountain range. Later, with the shortening and intensification of tectonic deformation, the Qilian Mountains terrain we see now was formed. This shortening process is actually accompanied by the gradual expansion of the Qinghai-Tibet Plateau to the northeast, the gradual uplift of the mountains, and the gradual subsidence of the basin. Through the evolutionary sequence of the basin, the researchers learned that the early Cenozoic sedimentary basin was a huge basin. The entire Qilian Mountains were previously covered under this basin. Probably from the middle Miocene, the Qilian Mountains as a whole began to rise rapidly, which divided the original basin structure and formed the Qaidam Basin in the south and the Hexi Corridor Basin in the north. After about two million years, it gradually became the geomorphic pattern of basins and mountains that we see today.

3. Impact: Formation of plateaus, establishment of landforms, frequent earthquakes

The strong tectonic movement that began 15 million years ago not only formed the Qinghai-Tibet Plateau, but also laid the foundation for the current topography of western China. Through the study of GPS observations, we found that the relative movement of the Indian and Eurasian plates is about 36 to 40 mm per year. The crustal shortening rate across the Qinghai-Tibet Plateau is 28 to 34 mm per year. This shows that 70% to 94% of the relative movement rate of the Indian and Eurasian plates is adjusted and absorbed by the internal deformation of the Qinghai-Tibet Plateau, which is the fundamental reason for the frequent earthquakes in western my country.

Strong tectonic deformation has continuously expanded the border of the northeastern Qinghai-Tibet Plateau, and has also repeatedly triggered strong earthquakes. According to historical records, there have been 19 strong earthquakes of magnitude 7 or above in the northeastern part of the plateau, and three earthquakes of magnitude 8 or above, namely the Haiyuan earthquake in 1920, the Gulang earthquake in 1927, and the Kunlun Mountain Pass West earthquake in 2001.

Today, the results of active tectonics have been used many times in the earthquake safety assessment of major national projects. Despite this, there is still a long way to go to understand the Earth. I believe that the secrets underground of the Qinghai-Tibet Plateau will eventually be revealed in the near future.