The issues related to the description of the structure and dynamics of deformation of a blocky natural environment are considered. It is shown that the formation of the rock mass structure and its changes are determined by the deformation regime. The allocation of active structural blocks in rock arrays cannot be based solely on determining their geometric dimensions. The defining feature of active natural isolation is the presence of a dynamically balanced dissipative structure in a certain volume of the array, which corresponds to a stationary deformation regime. The main directions of research in the field of geomechanics are formulated.

We present preliminary results of a numerical study of the behavior of zircon grains in a shear band filled with a model material with the properties of granite. Calculations performed in a flat formulation showed that the destruction of the zircon grain occurs much later than the fault filler material. The possibility of «survival» of a zircon grain in a band of width H is demonstrated when it is shifted by Δx to an average deformation of Δx/H ~ 0.2–0.4.

The electromagnetic triggering of earthquakes was statistically found over 30 years ago during an analysis of field experiments in the Pamirs and Northern Tien Shan for deep crustal sounding using DC pulses. However, the physical mechanisms underlying the triggering of seismic events by weak currents with densities of 10^-6 to 10^-7 A/m² remain unclear. This paper attempts to analyze these mechanisms based on theoretical estimates and laboratory experiments. The potential for generating additional stresses due to the piezoelectric effect, reducing the rock strength due to increased pore fluid pressure when an electric current flows through it, with corresponding Joule heating, as well as the potential for conductive fluid migration into a fault under the influence of the Lorentz force arising from the interaction of the current and the geomagnetic field are considered. It has been shown that none of the previously proposed hypotheses about the physical mechanisms of earthquake triggering by electrical/electromagnetic impacts can explain electromagnetic triggering phenomena in seismology at such extremely low current densities produced under field conditions by electrical impact on the Earth crust.

The study examines the possibility of estimating in-situ stress state parameters from the temporal evolution of microseismic events accompanying fluid injection into a porous reservoir. The approach is based on statistical modeling of microseismicity induced by pore pressure increase in a rock mass under frictional equilibrium. The relationship between the shape of event count versus pore pressure curves and the stress tensor parameters, as well as the characteristics of the orientation distribution of potential slip planes, is analyzed. It is shown that the evolution of microseismic activity is characterized by the presence of local maxima corresponding to tangency between Mohr circles and the Coulomb failure criterion, which makes it possible to relate their positions to the parameters of the stress state, in particular to the magnitude of the intermediate principal stress. It is established that under moderate anisotropy of slip plane orientations and a sufficient number of recorded events, the intermediate principal stress and the Lode–Nadai coefficient can be recovered with high accuracy. In contrast, at high anisotropy of orientations, the local maxima become poorly distinguishable, leading to a significant reduction in the informativeness of the microseismic activity curves. The obtained results demonstrate that the shape of microseismic activity curves can be used for a preliminary assessment of the stress state and horizontal stress magnitudes from microseismic monitoring data, as well as for evaluating the reliability of such estimates depending on the quality and volume of observations.

The problem of air pollution outside the quarry near the surface by blasting generated solid microparticles was considered in relation to the characteristic conditions of mining in Sitovsky limestone quarry in Lipetsk region. The average depth of the quarry is 50 m. The equivalent total power of the considered massive explosion was chosen to be 6 tons of TNT. The results were obtained by numerical solution of subsonic flow approximation of the Navier–Stokes equations in their full form for a compressible liquid. Eddy viscosity was taken into account within the framework of the Large Eddy Simulation method. The problem of wind-borne dust generation by explosion of single charge in borehole was solved. The size of the area where the concentration of microparticles with a size of less than 10 microns exceeds the maximum permissible values was estimated outside the quarry near the surface. It is shown that there is no dependence of the size of this area on the angle between the wind direction and the side of the quarry, and the size of the area in the wind direction is approximately 10 km in all the cases considered. The width of the time interval in which the concentration of microparticles exceeds the maximum permissible value near the surface varies from 5 minutes at a distance of 1 km to 15–20 minutes at a distance of 7 km from the quarry side and does not depend on the wind direction.

We present the results of instrumental observations conducted during the fall and explosive destruction of the Yakutian bolide. It was shown that the bolide caused variations in the Earthʼs magnetic field with an amplitude of 5‒25 nT at distances of up to ~ 6600 km, as well as variations in the electric field in the near- surface atmosphere with an amplitude of ~100 V/m, and microbaric variations in the form of an infrasound signal propagating along an atmospheric waveguide with an amplitude of ~ 15 Pa at a distance of ~ 4500 km from the impact site.

Ultra-low-frequency electromagnetic waves Pc1 (0.2–5 Hz); commonly known in the literature as «pearls» are excited in the outer radiation belt and propagate toward the Earthʼs surface along geomagnetic field lines as Alfvén waves. This discovery has had a profound impact on the development of magnetospheric physics. A series of pearls sometimes arise spontaneously; without apparent cause; and sometimes under the influence of triggers. This article; dedicated to the anniversary of the discovery; examines the triggered excitation of pearls. A classification of triggers acting on dynamic systems of the magnetosphere is presented. Two types; four classes; and eight kinds of triggers are introduced. Examples of triggers of natural and artificial origin are given. The concept of a trigger cascade is introduced. Particular attention is given to the anthropogenic periodic exogenous trigger of the pearls. It manifests itself as the so-called Big Ben effect. The essence of the effect is that a series of pearls is often excited immediately following a universal time marker. It is argued that the connection between the pearl excitation and the time markers is not random; but rather represents a rather mysterious geophysical phenomenon. It is hypothesized that the Big Ben effect occurs due to the impact of an unknown type of endogenous periodic artificial trigger on the radiation belt.