Seismometric monitoring of unstable rock mass in the Gunib district of Dagestan (North Caucasus)

Abstract

Relevance. The foothill and mountainous part of the territory of Dagestan is subject to dangerous geological processes, including collapses, which poses a certain threat in the places of residence of the population and the corresponding infrastructure (roads, power lines, gas pipelines, etc.). The issue of control over hazardous areas is very important and necessary, since a person cannot manage large landslides, and interference in the natural course of its development seems to be very problematic. To minimize damage, a forecast is required that determines, with maximum permissible accuracy, the state of the expected collapse and the zone of possible damage. The aim of the work is to develop new approaches, using geophysical observations aimed at understanding the initial genetic essence of landslides, and, based on the results obtained, to develop reliable methods for predicting catastrophic events. Methods. Seismic sensors can register vibrations not only of the earth’s surface, but also track the characteristic features associated with the state of individual massifs. The speed of propagation of seismic waves is influenced by a number of factors, such as rock temperature, moisture, mechanical stress and many other parameters. By changes in the seismic parameters of the rock, it is possible to track the unstable state of the rock mass, to determine the signs characteristic of the acceleration of the landslide process, the accumulation and removal of elastic stresses in the mass, indicating rock cracking. These data provide important information about the evolution of steep slope instability towards catastrophic failure. Results. For the first time in the Caucasus, the kinematic parameters of a landslide rock mass, which is in unstable equilibrium on a steep slope, posing a danger of collapse on the regional center Gunib in Dagestan, have been investigated. The quantitative and qualitative characteristics of various external dynamic influences, microseisms caused by storm cyclones in the ocean, earthquakes have been determined. Within the framework of the task, the natural frequencies and amplitudes of the rock mass vibration were determined, as well as its response to the fluctuations of a distant seismic event.