The Reference System in Determining the Parameters of Horizontal Deformations of the Earth's Crust on Geodynamic Polygons

The physical nature of quasi-static and transient anomalies in the geomagnetic field induced by underground explosions or earthquakes is reviewed. New theoretical results obtained recently and so far little known to general circles of geophysicists are presented. The physical nature of residual magnetic and electrotelluric fields at the explosion point are considered. The seismic waves from explosions or distant earthquakes are suggested to be used as a tool for the preliminary probing of the Earth's crust sensitivity to various seismo-electromagnetic effects. The use of magnetic induction effects for tsunami detection and for crust sounding is outlined. The nature of ULF magnetic impulses related with earthquakes is discussed.

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Stability of a Penny-Shaped Geothermal Reservoir in the Earth’s Crust

Journal of Energy Resources Technology ◽

10.1115/1.3230399 ◽

1982 ◽

Vol 104 (2) ◽

pp. 93-95 ◽

Cited By ~ 4

Author(s):

H. Abe´ ◽

H. Sekine ◽

S. Kitada

Keyword(s):

Critical Pressure ◽

Three Dimensional ◽

Tectonic Stress ◽

Theory Of Elasticity ◽

Surrounding Rock ◽

Geothermal Reservoir ◽

Earth’S Crust ◽

Dimensional Theory ◽

Opening Mode ◽

Earth's Crust

The theoretical analysis of a penny-shaped geothermal reservoir in the earth’s crust subject to linear tectonic stress gradients has been made on the basis of the three-dimensional theory of elasticity. The condition for stability of a reservoir requires K1 < Kc, where K1 and Kc are, respectively, the stress intensity factor for the opening mode and the fracture toughness of the surrounding rock. From this condition the upper critical pressure being necessary for the reservoir stability is obtained and is shown graphically.

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Analysis of the features of the spatio-temporal distribution of geoelectric inhomogeneities in the Earth’s crust and seismic events

EPJ Web of Conferences ◽

10.1051/epjconf/202125402003 ◽

2021 ◽

Vol 254 ◽

pp. 02003

Author(s):

Elena Bataleva

Keyword(s):

Temporal Distribution ◽

Physical Nature ◽

Tien Shan ◽

Earth’S Crust ◽

Seismic Events ◽

Magnetotelluric Data ◽

Geological Conditions ◽

Spatio Temporal ◽

Earth's Crust ◽

The Relationship

The paper presents the results of experiments carried out at the regime points of magnetotelluric monitoring both on the territory of the Bishkek geodynamic test site (Northern Tien Shan) and on a series of monitoring profiles in various geological conditions. Previous studies indicate the relationship of variations in the electromagnetic and seismic fields, lunisolar tidal effects, seismic regime with the processes of fracturing. The purpose of this work is to establish the features of the relationship between the spatio-temporal distribution of seismicity and the distribution of geoelectric inhomogeneities in the Earth’s crust (fault-block tectonics of the region). Based on the analysis of the results of the interpretation of magnetotelluric data (2D inversion) and new detailed seismotomographic constructions, the verification of geoelectric models was carried out, the analysis of the distribution of hypocenters of seismic events was carried out. Special attention was paid to the confinement of earthquakes to listric fault structures. The relationship between the distribution of the hypocenters of seismic events and the spatial position of the electrical conductivity anomalies is confirmed by the authors explanation of the physical nature of the identified conducting structures, based on hypotheses of fluidization and partial melt of the Earth’s crust.

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Features of the Tien Shan newest orogen morphostructure

LITOSFERA ◽

10.24930/1681-9004-2021-21-5-747-774 ◽

2021 ◽

Vol 21 (6) ◽

pp. 747-774

Author(s):

M. G. Leonov ◽

E. S. Przhiyalgovskii ◽

A. K. Rybin ◽

G. G. Shchelochkov

Keyword(s):

Reference Points ◽

Tien Shan ◽

Earth’S Crust ◽

Linear Wave ◽

Tectonic Structure ◽

Centrally Symmetric ◽

Earth's Crust ◽

Concentrated Deformation ◽

Granite Basement ◽

Symmetric Structures

Research subject. The concept of morphostructure implies the presence of a relationship between the relief forms of segments of the Earth’s crust and their structural and material content. This article describes the geological ensembles of the Tien Shan orogen, the tectonic structure and modern relief of which differ in their parameters from the general morphostructural plan and which, therefore, belong to the category of morphostructural anomalies. Materials and methods. The data presented in the article were obtained in the course of field structural-geological and morphostructural study of key segments of the Tien Shan orogen, as well as an analysis of materials from previous research, including the results of geophysical sounding of the Earth’s crust and geodesical monitoring of relative modern movements of reference points on the surface.Results. The article demonstrates that, against the background of the general linear-wave morphostructure of the Tien Shan orogen, there are areas whose relief and tectonic structure do not agree with the general tectonic plan of the mountain. Wi thin the considered region, different types of morphostructural anomalies are identified and described, reflecting the speci fics of the evolution and geotectonic position of individual volumes of upper-crust rock complexes: zones of concentrated deformation and tectonic joining; centrally symmetric structures formed on the site of paleoatolls; neotectonic protrusions of the granite basement; trans-regional zone of the Talaso-Ferghana Fault and other structures. Conclusion. The formation of morphostructural anomalies is associated with the presence of non-trivial geodynamic environments operating against the background of the tectonic regime common to the Tien Shan. The modern morphostructure of the Tien Shan is the result of interference between various geodynamic regimes and settings: a regime common to the entire territory of the orogen and particular regimes that manifest themselves sporadically and are reflected in the modern relief.

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