Ice-rock avalanches in areas of intracontinental alpine glaciation affected by arid
climate may be a more frequent occurrence than it seems. In the Mongolian Altai, which is
characterized by high seismicity, earthquakes are among the triggers of such events. In August 1988,
17 days after the Tsambagarav earthquake (M=6.4), the collapsed fragment of one of the glaciers
initiated an ice-rock avalanche “on an air cushion” in the Zuslan river basin (Tsambagarav Ridge).
Avalanche deposits up to 30 m thick blocked the valley for 5 km. Field observations in the Zuslan
river valley were carried out 16 and 31 years after the event (in 2004 and 2019). They allowed to
establish the duration of ice degradation in the avalanche deposits and to describe geomorphological
effects. Analysis of different time satellite images, as well as calculations of the ice thickness in the
glacier and in the collapsed ice block made it possible to clarify the mechanism of avalanche
initiation. Due to the loss of ice both in the glacier tongue and in the area of accumulation, after the
earthquake the affected glacier was shrinking much faster than neighboring glaciers.