The 1911 Sarez earthquake occurred at 18:41 UTC on 18 February (23:31 local time)[2] in the central Pamir Mountains in the Rushon District of eastern Tajikistan (then part of the Russian Empire).

[1][5] The earthquake caused the waters of Lake Karakul to surge over its eastern rim, leaving behind a large sheet of ice as it withdrew.

[2] The earthquake triggered numerous landslides along the slopes of the Bartang, Tanimas and Murghab valleys.

[2] The largest of these blocked the Murghab river, forming the Usoi Dam and creating the Sarez and Shadau lakes.

[2] The landslides and the formation of Sarez Lake caused significant migration of the inhabitants of the upper Bartang valley.