A giant avalanche of rocks has resulted in the formation of a dam which has created a lake. This new feature was discovered during geological mapping of the Dund Tsenkher river valley in the Munhkhairkhan Soum (district) in the Western Mongolian Altai.

The rock avalanche was most likely triggered by an earthquake related to the activity of the Tolbonuur and Hovd geological faults. Although the area is sparsely populated, the settlements of the Munhkhairkhan Soum are threatened by rockfalls or even by rock avalanches that could be triggered by future earthquakes along these faults.