Underestimated number and significance of rock glaciers on the Tibetan Plateau.

Rock glaciers, periglacial landforms with tongue- or lobe-shaped streams of slowly deforming frozen debris, play an important role in periglacial mountainous regions. The understanding of rock glaciers and their geoecological role at regional scales has been considerably hampered due to survey difficulties. We employ an automated approach for identifying rock glaciers and compile for the first time a complete rock glacier survey over the entire Tibetan Plateau. We find over 130,000 individual rock glaciers, much more than expected from previous inventories over any areas on Earth, also suggesting that the global number of rock glaciers is significantly underestimated today. We reveal an underestimated source of water storage to the Asian Water Tower and an enormous material flux due to rock glacier creep, which warrants consideration for its potential impact on downstreams. This result is also important for improving the modeling of mountain permafrost for a better anticipation of climate change impacts.