Estimation of seismic impacts under conditions of permafrost degradation

Abstract

Permafrost is widespread in Russia in many mining and oil regions. Some of these areas are located in zones of high seismic activity. In connection with global climate change and possible degradation of permafrost, it is necessary to study the seismic properties of frozen and thawed soils in northern regions, as well as the processes affecting their change. The solution of these problems requires an assessment of the influence of natural factors on the spectral composition and dynamic range of seismic vibrations in the upper layers of the section during earthquakes. The influence of short-term (seasonal thawing-freezing of active layer) factors and long-term (temperature trends) factors on seismic vibrations can be used for predicting changes in seismic conditions in seismically active regions. We present generalization of soils seismic properties and their reflection in the field of elastic wave velocities and oscillation amplitudes. A number of seismo-geocryological models, which can be used for solving engineering-geocryological problems in seismology, are considered. The importance of monitoring the seismic properties of soils during permafrost degradation is emphasized. An approach for estimating seismic hazard based on computational methods of seismic microzoning is proposed.

Keywords

• permafrost
• seismic properties of frozen and thawed soils
• monitoring