Rockslides in the open pit of kumtor goldmine (Kyrgyzstan)

Abstract

The high-elevation Kumtor mine is located in the Central Tien Shan in the permafrost and active glaciers area. This area is characterized by extreme continental climate. The average annual temperature in the mine area is _7.8 °C with fluctuations in the average minimum temperature of _28.8 °C in January up to 1.7 °C in July. The average annual precipitation is 350–400 mm, a quarter of which falls as rain and the rest in the form of snow. Harsh climatic conditions in the area, the presence of mountain glaciers and permafrost rocks, diversity of terrain, rock types, seasonal freezing and melting of the rocks and soil together with global warming and large-scale anthropogenic impact cause active development of cryogenic gravitational processes. The most dangerous among them are repeated slumping and sliding of the north-eastern wall of the Central pit. The report presents the results of geotechnical studies and analysis of the main reasons for the failure of the pit walls, which include melting of the permafrost rocks at the top of the pit and glacial water inflow into the tectonic disruption zone.