Chinese scientists unveil comprehensive inventory of Tibetan Plateau's vast rock glaciers

While glaciers come to mind when people think of the Tibetan Plateau's "solid reservoir", the number and significance of rock glaciers — creeping masses of ice-rich debris hidden beneath thick layers of rock and soil — have been underestimated.

Now, Chinese scientists have released the first comprehensive inventory covering the entire plateau, identifying 132,867 rock glacier units spanning 16,500 square kilometers. The count exceeds the sum of all previously known rock glaciers worldwide, pointing to a long-standing underestimation of both their number and their role in the plateau's frozen water reserves.

The study, conducted by researchers from the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences, was published in the journal Science Bulletin. The dataset is made public through the National Tibetan Plateau Data Center.

Rock glaciers are not glaciers but are periglacial landforms composed of ice-bearing debris that slowly creep downhill in cold alpine environments. They serve as indicators of mountain permafrost and potential reservoirs of solid water. The Tibetan Plateau, dubbed the Asian Water Tower, contains one of the largest concentrations of mid-to-low latitude permafrost on Earth, nurturing many rock glaciers.

However, a comprehensive and unified dataset tracking the movement of rock glaciers has been elusive, largely due to the challenges posed by the region's high altitude, rugged terrain and the labor-intensive nature of manual data interpretation.

The research team integrated high-resolution optical remote sensing imagery, radar data and digital elevation models to develop a deep learning method for automatically detecting rock glaciers across the plateau. They employed multi-temporal radar techniques to extract surface deformation rates, obtaining kinematic data for 99.3 percent of the cataloged features.

Beyond location and boundaries, the inventory also records morphological type, terrain attributes, glacier connectivity and motion status for each unit, supporting research into rock glacier activity and periglacial geomorphic dynamics.

Notably, the team estimated that ice stored within the plateau's rock glaciers is equivalent to roughly 92 to 186 cubic kilometers, comparable to the storage capacity of dozens of large reservoirs.

"This represents a solid-water reserve in the Asian Water Tower that has been largely underestimated," Feng Min, a professor at the institute who led the study, said.

"This discovery could have substantial implications for long-term hydrological regulation in regions lacking glaciers or where glaciers are rapidly retreating," Feng added.

The dataset also provides insights into geohazard risks. Rock glaciers creep continuously, and where they intersect roads or river valleys, they can trigger ground deformation, river blockages and debris flows. By documenting the spatial relationship between rock glaciers and nearby infrastructure, the inventory offers a new tool for mountain hazard assessment, Feng noted.

"We used to lack direct geomorphic evidence when mapping permafrost. Rock glaciers are natural markers pointing to where frozen ground exists," Feng said, adding that the inventory can therefore support permafrost mapping, model calibration and climate change impact assessment across the plateau.

He said that the dataset is expected to support permafrost monitoring, water resource assessment, cryospheric hazard identification and surface process modeling, while providing an important baseline for reassessing the global extent and water storage of rock glaciers in cold mountain regions.