Abstract. During 2006–2014 in the western Teskey Range, Kyrgyzstan, four large drainages from glacial lakes have occurred. These flooding events caused extensive damage, killing people and livestock as well as destroying bridges, roads, homes, and crops. According to satellite data analysis and field surveys, the volume of water that drained at Kashkasuu glacial lake in 2006 was 198,000 m3, that at Jeruy lake in 2013 was 163,000 m3, and that at Karateke lake in 2014 was 169,000 m3. Due to their tunnel outlet, we refer here to these glacial lakes as a tunnel-type of short-lived glacial lakes that drastically grow and drain over several months. From spring to early summer, such a lake either appears, or in some cases, significantly expands from an existing lake, and then drains during summer. Our field surveys show that these short-lived lakes form when the ice tunnels inside a debris landform get blocked. The blocking is caused either by the freezing of stored water during winter or from collapse of the ice tunnel. The draining occurs through an open ice tunnel during summer. The growth–drain cycle can repeat when the ice-tunnel closure behaves like that on supraglacial lakes on debris-covered glacier. We argue here that the geomorphological conditions in which such a short-lived glacial lake appears are (i) existence of an ice-containing debris-landform (moraine complex), (ii) existence of lake-basin depressions having its water supply on a debris-landform, and (iii) no surface water channel from lake-basin depressions. Using these geomorphological conditions, we examined 60 lake-basin depressions (> 0.01 km2) in this region and identify here 56 of them that are potential locations for a short-lived glacial lake.
Seasonal drainage of supraglacial lakes on debris-covered glaciers in the Tien Shan Mountains, Central Asia