Earth’s Cryosphere, 2017, Vol. XXI, No. 1, p. 23-31
SEISMOGENIC LANDSLIDE STRUCTURE AND EVOLUTION IN THE PERMAFROST AREA OF THE ALTAI MOUNTAINS (GORNY ALTAI)
M.S. Dostovalova1, V.V. Olenchenko2
1 Joint Stock Company “Geological company “Altay-Geo”,
52, Zavodskaya str., Mayma, Altai Republic, 649100, Russia; ya.toyma@yandex.ru
2 Trofimuk Institute of Petroleum Geology and Geophysics, SB RAS,
3, Koptuga ave., Novosibirsk, 630090, Russia; OlenchenkoVV@ipgg.sbras.ru
This article presents and discusses results of multiyear observations and electrical resistivity tomography studies of one of the seismogenic landslides on the territory of Gorny Altai. The study has revealed that the landsliding occurred in 2008, during the period of enhanced seismicity of the Altai-Sayan region. This is shown to be a cirque-like landslide of complicated morphology resulted from the unconsolidated deposits movement along the permafrost table. The permafrost thicknesses predicted from geophysical data vary from 22–30 m to 10 m in fault zones. During the 2008–2015 observations, the maximum displacement of the landslide scarp was 62 m, with the annual growth of its area averaging 278 m2 (in the range from 45 to 651 m2/year). The landslide evolution is characterized by short-term periods of activation against the backdrop of the generally declining landslide activity. These are associated with a short-term burst of seismic activity in the region when the mean summer air temperature increased by 2.1 °C versus the multiyear norm. The results of the study allow suggesting that further growth of the mean annual and summer temperatures in the Chuya seismogenic zone of Gorny Altai will lead to activation of landsliding processes.
Seismogenic landslide, mountain permafrost, electrical resistivity tomography