The Third Pole's Watchtower
High on the Qinghai-Tibet Plateau, often called the "Third Pole," the Wudaoliang Permafrost Research Station operates in a region defined by extreme cold and thin air. Managed by the State Key Laboratory of Cryospheric Science, a part of the Chinese Academy of Sciences, this facility is a significant site for understanding frozen ground on Earth. The station sits within a vast expanse of continuous permafrost, a layer of soil that remains at or below 0°C for at least two consecutive years.
The environment here is harsh. The mean annual ground temperature in the region is generally warmer than -1.5°C, making it particularly sensitive to climate shifts. The permafrost itself can be over 100 meters thick. An important area of study is the "active layer," the upper layer of soil that thaws during the summer and refreezes in the winter. At Wudaoliang, this layer is typically between 1.5 and 3 meters deep. Decades of monitoring have shown this layer is deepening. Between 1996 and 2001 alone, the active layer across the plateau increased in thickness by 0.15 to 0.50 meters.
Engineering on Unstable Ground
The data collected at Wudaoliang has direct, practical applications for major infrastructure projects. The station is located along the corridor of the G109 highway and the famous Qinghai-Tibet Railway, which traverses 632 kilometers of continuous permafrost. Building on frozen soil that thaws and refreezes presents enormous engineering challenges, as the ground can sink, heave, or become unstable.
To understand these processes, scientists at Wudaoliang use a network of boreholes to monitor ground temperatures at various depths. Long-term measurements show a clear warming trend. From 1996 to 2006, permafrost temperatures at a depth of 6 meters along the highway increased by about 0.12°C. This information helped design the railway. Engineers developed innovative solutions based on research from the station, such as building embankments of crushed rock to insulate the permafrost and installing thousands of thermosyphons—passive heat-exchange pipes that pull heat out of the ground during the frigid winters to keep the foundation stable. Over 20,000 thermosyphons are installed along the railway, each one standing about 2 meters above the ground.