On the 70th anniversary of the 1949 Khait Earthquake in Tajikistan

Abstract

In connection with the 70th anniversary of the Khait earthquake of July 10, 1949, information is presented on the parameters, features of manifestation, and effects of this seismic event. The most important effects of the earthquake and causes of numerous casualties are considered. Photos showing the earthquake’s effects are presented from the personal archive of V.F. Bonchkovsky, who headed the commission for examination of the epicentral zone. The Khait earthquake of July 10, 1949, is the strongest known in the South Tien Shan–Tajik Depression junction zone. It was preceded by two strong foreshocks, followed by a very large number of aftershocks, including strong ones. Seismic vibrations damaged buildings over a large area. However, the destructive effects of the Khait earthquake are mainly related to its secondary manifestations: the occurrence of a large number of landslides, mudflows, and rock and earth avalanches. They directly resulted in a huge number of victims and led to significant geomorphological changes in the epicentral zone. As a result of a rock–mud avalanche, the district center of Khait was buried along with its inhabitants. A total of 33 settlements were destroyed by mudflows. In total, about 28 000 people died, comparable to the number of victims of the 1948 Ashgabat and 1988 Spitak earthquakes. The disaster was so vast because this very strong earthquake occurred in an area characterized by very high landslide activity during a period of very strong slope humidification, i.e., a period of very high instability.