Introduction: Since the 90s of the XX century, the principles of fractal geometry began to penetrate into geology, and this aspect of research is attracting more and more attention. At the same time, basin analysis was developed, but ideas about fractal geometry were not used to describe the structure of sedimentary basins. This article is an attempt to link the observed patterns of the structure of sedimentary basins with the principles of fractal geometry. Objects of research: A number of negative structures of the earth›s crust have been studied: Proterozoic Onega and Orsha mulds, Paleozoic Michigan basin, Mesozoic and Cenozoic Tien Shan depressions, Pre-Caucasian trough, the Sunda shelf, the El Rif. Research methods: The paper uses a comparative structural and tectonic analysis of geological objects. To explain the revealed regularities of the structure of sedimentary basins the concepts of fractal geometry in its descriptive aspect are involved. 
Results of the study. The fundamental property of sedimentary basins has been established - the differentiation of primary sedimentary baths into a system of secondary anticlinal (elevation) and synclinal (deflections) linear morphostructures. The spatial ordering of intra-basin uplifts and depressions, expressed in the arrangement of the axial planes of structures with a step from 15–25 to 30–50 km, as well as the hierarchical dimension (from mega- to micromasshtba) of structures in the rocks of the foundation of the basins, have been established. Discussion of the material: Multi-order basin structures have a similar structure, orderliness of spatial arrangement and geometric pattern, and, therefore, are to a certain extent hierarchically constructed self-similar objects, which indicates their fractal nature. This position is confirmed by the emergence of structures such as viscous fingers(viscous fingers), which have a fractal nature. Conclusions: These data make it legitimate to apply the principles of fractal geometry to the description of sedimentary basins and allow the consideration of «solid» crystalline rocks of the foundation of sedimentary basins within the framework of the laws of hydrodynamics.

The paper considers the results of many years of research related to the development of an approach to the medium-term earthquake prediction within the Baikal Rift Zone in order to more effectively ensure the seismic safety of the local population and infrastructure. To analyze the seismic regime at the stages of preparation of dangerous earthquakes with K≥13 (M≥5.0), the developed geoinformation system “Prediction” based on the well-known method of pattern recognition was used. In order to better understand the geological conditions for the preparation of earthquake sources, full-scale experiments on the type of slider models in the Angara fault zone were carried out together with specialists from the institutes of the Russian Academy of Sciences in order to determine the geomechanical conditions for the occurrence of seismic oscillation sources. As a result, a two-stage seismic event preparation regime was revealed, which was further used to improve the medium-term forecast. The study of exhumed paleo-earthquake sources yielded important geological and geophysical data on the thermodynamic and geomechanical conditions for the preparation of paleo-earthquake sources in the zone of the marginal suture of the Siberian Craton, 
which occurred in the bowels of the earth›s crust during past epochs of seismotectonic activations. The collected information was used in the development of methods for man-made impacts on seismically hazardous fault segments in order to reduce their seismic potential. When analyzing the totality of the collected materials, it was found that the most informative criteria for identifying the places of preparation of the emerging sources of dangerous earthquakes are: segments of high-ranking seismically active faults or their intersection nodes, as well as seismic gaps in the epicentral field in combination with signs of increasing seismic activity on their periphery that occurs in the last decade. As an example, the data of the medium-term forecast for the period 2019-2022 are given. It has been established that the percentage of epicenters of occurred earthquakes with the specified energy falling into their waiting areas, indicated in the report sent in 2019 to the Ministry of Emergency Situations of the Irkutsk Region, is 76%. The authors are making efforts to improve the approach to improving the medium-term forecast in relation to the features of the seismic regime in the BRZ based on the use of an experimentally substantiated two-stage earthquake preparation model to obtain formalized estimates of the other two basic forecast parameters “E” - energy and “T” - event waiting time. In conclusion, conclusions are presented about the increased importance of the medium-term forecast in seismic hazard assessments, as well as about the existence of 
ways to dampen the destructive consequences of future earthquakes using man-made impacts on the fault segments identified during the forecast with signs of preparation of dangerous earthquakes in the coming years. 

Physical modeling of the process of formation of the shear zone in single-layer ones is carried out in order to elucidate the features of fracture formation in the rheologically inhomogeneous sedimentary cover of the platform over the active fractures of the foundation. Model materials were montmorillonite clay water paste and wet sand. It is shown that the thickness of the deformable layer determines the width of the shear zone, the time of onset of rupture formation in it and the duration of the implementation of the stages of its development, and its rheological properties determine the features of its internal discontinuous structure.

Based on catalogue of velocities of Central Asian GPS network’s observation points we computed a distribution of values of contemporary 2D strain tensor of Earth surface for most part of Pamir and its neighbor tectonic formations and also for parts of Central and Western Tien-Shan. The velocity catalogue was gained as the result of processing data from many years of GPS observations conducted in the framework of field expeditions by Research station of Russian Academy of Sciences in Bishkek. The computation of Earth crust strain was done using data from sets of three or four neighbor GPS points for computation of each single strain tensor value. By matching the results of computations against maps of regional faults and tectonic structures we mark out the most tectonically active areas and describe types of contemporary surface deformations within them. The most rapid deformation within the region of study is shortening with moderate right lateral shift across the Main Pamir Thrust. The northern part of Karakul Graben at Pamir show moderate tectonic activity as transversal (east-west directed) extension. Normal faults in Kongur-Shan (East Pamir Pull-apart) also undergo transversal extension in their northern part. At central and eastern parts of Tajik Depression we observe latitudinal shortening while in zone of conjunction between Tajik Depression and Gissar ridge we have presumably right lateral shift. There is also significant shortening across main tectonic structures of Naryn basin. Area around Toktogul water storage reservoir undergoes longitudinal shortening. At Jumgal and Kochkor basins we have shortening along north-northwest direction as well as longitudinal shortening across Suusamyr basin. Inside Chu basin we clearly observe two latitudinally-elongated zones rapid longitudinal shortening.

To evaluate the geodynamic and geoecological safety of field development, studies related to the assessment 
of the impact of mass explosions on the filtration properties of a water-saturated reservoir are of particular 
importance. Use of high-precision sensors installed in observation wells promotes the transition to a new 
level of scientific and methodological support of mining operations and provides monitoring of the 
technogenically disturbed groundwater regime. Since July 2019, within Korobkovsky and Lebedisky iron 
ore deposits of the Kursk Magnetic Anomaly (city of Gubkin, Belgorod Region) have been made a precise 
observations of the reaction of the «reservoir-well» system under explosion impact. Along with coseismic 
hydrogeological responses to the passage of seismic waves from mass explosions carried out in a mine and 
a quarry, decrease of level of supra-ore aquifer are traced. Marked effect are determined a formation and 
filling of zones of technogenic fracturing, renovation of existing cracks. The results of repeated pumping 
and geophysical well logs, carried out in October, 2021, indicate an ambiguous change in the filtration 
properties of water-saturated reservoirs under the influence of mass explosions. The obtained experimental 
data can be used to develop a methodology for predictive assessment of the postseismic effects, which will 
minimize the risks of possible accidents during the exploitation of hard mineral deposits with explosive 
technologies.

The processes of rock transition from undisturbed to dynamic fracture before earthquakes, under conditions of limited source zone volume and compression at great depths, are slow. Such a slowdown can be used for predictive purposes. According to natural waveguides, which are fault zones, these processes in the depths of the lithosphere cause variations in geophysical fields on the Earth's surface, in the atmosphere and ionosphere. In turn, these variations can already be seen by modern ground and satellite observations.
This article presents the results of mathematical and computer modeling of dynamic and quasi-static processes in earthquake focal zones. The motion of an elastic medium in the event of a sudden rupture along a finite strip under longitudinal shear conditions, taking into account contact viscous friction, is investigated. The use of an exact solution to this problem, constructed by the superposition method, is convenient for the first arrivals of reflected waves and is difficult with multiple reflections. In this regard, a different approach has been applied in this paper, which consists in reducing the boundary value problem to the Fredholm integral equation of the 2nd kind in images, the solution of which, under certain conditions, allows us to obtain the parameters of the motion of the medium at an arbitrary time. These conditions are sufficiently large values of the effective viscosity at break when a quasi-static non-stationary process is realized. Applying the method of solving integral equations in images, which uses the Hilbert-Schmidt formula for a resolvent kernel and decomposition of a normalized symmetric kernel into a bilinear series by eigenfunctions, a solution of a quasi-static integral equation in images is obtained. Further, by inverting the solution in the images, the original solution is obtained.
From the conditions of proximity of the approximate (quasi-static) solution and the general (dynamic) solution of the corresponding integral equation, an estimate of the lower bound of the effective viscosity at break is obtained for the transition from solving a dynamic non-stationary problem to solving a quasi-static non-stationary problem. The correspondence of the obtained condition of quasi-static processes to the available experimental laboratory and geophysical data is investigated.
With the help of analytical methods, together with numerical calculation, graphs of quasi-static nonstationary displacements of the rupture shores and the stress intensity coefficient at its ends, depending on background stresses, effective viscosity at the rupture, coordinates and time are obtained. A general solution of the quasi-static problem for displacements and displacement velocities of the rupture shores in the form of a static surface in a normalized coordinate system is obtained. A general solution of the quasi-static problem for the intensity coefficient of tangential stresses at the ends of the rupture in normalized coordinates is obtained.

Many researchers note the nonlinearity of flow in tight rocks. This manifests itself in the form of a decrease in effective permeability with a decrease in flow rate. For low-permeable rocks, the estimation of reservoir permeability without taking into account the nonlinearity of the flow can yield significant errors. Accounting for non-linear flow can also lower the estimate of reservoir productivity and lead to an increase in stationary oil zone estimation. Regular methods of studying fluid flows in porous rocks are poorly suited to study their permeability when approaching to zero fluxes. Previously, we described a method for laboratory testing of non-linear flow in low-permeability rock samples, based on measuring flux during a slow decline in the pore pressure gradient. A feature of the described technique is that the flow rate of the liquid is measured by its continuous weighing. This method of measurement allows us to study very slow flows, but it requires a special approach to calculating the flow rate from mass change data. One of these approaches is the TotalVariation Regularization method, which is often used in the problems of filtering noise in images. We investigated the possibility of using this method to analyze the results of measuring infinitesimal flow rates based on the mass change. As a result, it was shown that this method has a number of advantages, and in combination with the proposed modification of the quality functional, it allows processing significantly irregular data. The method proposed by us can be used in research work for a more accurate assessment of the permeability of dense rocks, the filtration properties of which can be significantly non-linear.

Сontinuous observations have been carried out by vertical sounding at the ionospheric station in Novosibirsk (54.84°N, 83.23°E) since the late 1960s of the XX century. The digital ionosonde “PARUS” has been installed since 1995, thanks to which an archive of continuous series of ionospheric parameters obtained by one instrument in one place was accumulated in digital form. To study the morphological features of the behavior of the ionosphere over Novosibirsk, we chosen the critical frequency and virtual layer height Es (foEs and h’es, respectively) as parameters characterizing the state of the lower ionosphere. The accumulated material made it possible to analyze the observation probabilities (PEs) of this layer in each month depending on the time of day and height of appearance for the period from 1996 to 2019, which covers the 23rd and 24th eleven-year solar cycles. There was no direct dependence on the level of solar activity, which was represented by Wolf numbers (the number of sunspots). To study the conditions for the formation of the sporadic Es formation, the statistical relationship between solar and magnetic activities in the period from 1996 to 2019 was considered. It was shown that with an unstable relationship between solar and geomagnetic activities, the appearance of a sporadic layer is more likely. The probability of the appearance of Es shows a clear dependence on the season and hour of the day. In January-February 2002, the Es layer was rarely observed (PEs about 15%), while, as in other years, this value was on average 40-45%, and in 2011 it reached 80%. In July and August, the appearance of the Es layer is almost 100%. The most probable time of occurrence of the sporadic layer falls on the period from sunrise to sunset, regardless of the month of observation, and in summer there are two peaks, when it is observed 100% - these are local daytime and pre-sunset hours, the minimum PEs occur at night hours in winter. The number of occurrences of Es in specific altitude ranges is analyzed, the time series of this value repeats the solar cycle: low Es (100-110 km) are more often observed at solar minimum, and higher ones (115-130 km) - at solar maximum. A seasonal dependence was revealed: lower sporadic layers (100–130 km) appear in greater numbers in summer, and higher Es (> 135 km) in spring and winter. The formation of the Es layer during the preparation and realization of earthquakes in the region of 200–300 km from the ionospheric station is discussed. An unambiguous response of the lower ionosphere to these events has not been revealed.

There exist purely hydrodynamic models for tornado-cyclone, i.e. rotating under the action of Coriolis forces thundercloud from which tornado funnels usually form. However there are known superfast cases of appearing tornado-cyclone and its replenishment with ascending vortices of degassing nature which were described in a famous monograph by D.V. Nalivkin and were observed over the Amur Bay on 20.09.1997 near Vladivostok. For modelling similar degassing generated tornado-cyclones in a quasistationary stage it is convenient to use magneto-hydrodynamic analogy between the equations system of equilibrium magneto-hydrodynamic configurations in the theory of controlled thermonuclear fusion for the pair {magnetic field – electric current} and the pair {velocity – vorticity} in case of steady ideal incompressible fluid currents. Like tornado-cyclone model is suggested basing on algebraic Grad –
Shafranov equation solution for tokamak with D-shaped section; when tokamak magnetic surfaces equation allow determine magnetic field and electric current distribution and then derive similar formulas for velocity and vorticity fields in tornado-cyclone using magneto-hydrodynamic analogy. In order to complete this model, one should place an ascending column-shaped vortex into the central tornado-cyclone zone taking into account pressure equality on external side of this degassing vortex and on internal torus border.

The paper presents a comprehensive analysis of the TEC dynamics during X-class solar flares that occurred in September 2017. The increase in the intensity of X-ray and ultraviolet radiation, observed during chromospheric flares on the Sun, causes an immediate increase in the electron density in the entire ionosphere. In this study, we developed a method for estimating the change in the TEC of the ionosphere caused by a burst of solar activity. Based on the results obtained, the wavelength range was determined, which to a greater extent determines the change in the value of the total electron content of the ionosphere during solar flares.

On the basis of new ideas about the geological environment, a degassing model of the seismic process controlled by planetary hydrogen degassing was substantiated. Models of crustal seismic acts and DfSE are proposed. For the lithosphere, these are rapid movements along the boundary structures, for the deep-focus seismic events (DfSE) - an «explosive» release of hydrogen as embedding atoms, causing deformation of the hydrogen sublattice. The driving forces of the wave seismic process in the lithosphere, which is extremely energy-saturated in elastic energy, are the floating deformation waves of a diffusive nature, activated by continuously ascending hydrogen flows, providing a self-sustaining seismic process. The trigger action of hydrogen fluxes on the parameters of boundary structures is realized, which control slow (background mode) or fast movements of the elements of the medium relative to each other (weak events - in the background mode). Hydrogen activation of boundary structures translates the process of movement of the elements of the medium relative to each other into a barrier-free process with features of superplasticity. Manifestations of the strongest and mega events occur with additional activation of boundary structures by hydrogen flow due to local activation in the upper mantle of Vadkovsky›s «seismic nails». The continuous upward flow of hydrogen ensures the seismic interaction of processes in the upper mantle and lithosphere and controls the self-sustained seismic process in a wide range of depths.

Academician V. V. Adushkin, founder and first director of the Institute of Geosphere Dynamics of the Russian Academy of Sciences, occupies a prominent place among outstanding geophysicists. On September 10, 2022, V. V. Adushkin celebrated his 90th birthday. The fame of V. V. Adushkin is connected with his pioneering researches of explosive processes, in particular, nuclear explosion, ensuring the safety of underground nuclear tests, as well as numerous works in the field of fundamental problems of geophysics