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

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.

An integrated approach to assessing the geodynamic activity of the Earth's crust in the low seismic East Baltic region

2021 ◽  
Author(s):  
Valerijs Nikulins
Keyword(s):  
Seismic Hazard ◽  
Vertical Velocity ◽  
Practical Importance ◽  
Earth’S Crust ◽  
Macroseismic Data ◽  
Tectonic Fault ◽  
Baltic Region ◽  
Geological Conditions ◽  
Earth's Crust ◽  
Geodynamic Activity

<p>The East Baltic region (EBR), located on the ancient Precambrian East European Craton, is characterized by low seismic and deformational activity. The EBR is located at a distance of about 2000 km from the divergent zone in the North Atlantic and from the convergent zone in the Mediterranean Sea.</p><p>Nevertheless, historical and modern earthquakes have occurred in the EBR. Historical earthquakes occurred in 1616 (<em>Bauska</em>, Latvia, VI), 1670 (<em>Pärnu</em>, Estonia, VI), 1821 (<em>Koknese</em>, Latvia, VI), 1823 (<em>Võrtsjärv</em>, Estonia, VI), 1857 (<em>Irbe</em>, Latvia, VI), 1896 (<em>Jelgava</em>, Latvia, V), and modern earthquakes occurred on 10/25/1976 (<em>Osmussaar</em>, Estonia, M 4.7), 09/21/2004 (<em>Kaliningrad</em> region, Russia, Mw 5.2).</p><p>The study of slow (tectonic creep) and fast (earthquakes) deformations is practical importance in EBR for safety of energy facilities - <em>Plavinas</em> HPP, <em>Baltic</em> (Kaliningrad region of Russia) NPP and <em>Ostrovets</em> (Belarus) NPP.</p><p>In the central part of the territory of Latvia, signs of geodynamic activity of the Earth's crust have been identified. A characteristic feature is the trans-regional <em>Olaine-Inčukalns</em> tectonic fault, which crosses the Riga agglomeration. The fault is traced in the <em>Caledonian</em> structural complex.</p><p>Previous studies on seismic hazard assessment in Latvia (Safronovs & Nikulins, 1999; Nikulins, 2011) were based on combination of seismic, geophysical, geodetic and geological data. These studies made it possible to assess the seismotectonic potential of the Earth's crust, parameters of seismogenic zones and to state a very low seismic activity.</p><p>A sparse seismic network and poor seismic-geological conditions affect the effectiveness of seismological monitoring in EBR. To understand of driving mechanisms for earthquakes, results of remote sensing (<em>Persistent Scatterer Interferometry - PSI</em>) of surface (1992 - 2000), studies of radon anomalies (2014), and macroseismic data (2010) were used.</p><p><em>PSI</em> method made it possible to reveal the anomalous vertical velocity (25.4 mm/year) of opposite sides of fault, adjacent to the <em>Olaine-Inčukalns</em> fault in the southwest of Riga. The average vertical velocity does not exceed 1.03 mm/year. The study of the radon field in northeast of the <em>Olaine-Inčukalns</em> fault revealed an intense (140000 Bq/m<sup>3</sup>) radon anomaly (Nikulins, 2014).</p><p>In addition, on 22.11.2010, population of Riga and its environs felt shaking. Mechanism of the <em>Olaine-Inčukalns</em> fault is predominately <em>thrust faulting</em> with a <em>strike-slip</em> component, whereas mechanisms of most other faults in Latvia are <em>normal faulting</em> type.</p><p>These signs indicate the activation of the <em>Olaine-Inčukalns</em> tectonic fault. Thus, on the EBR, under conditions of slow deformation of the Earth's crust, a comprehensive analysis of various geological, geophysical and deformation parameters has justified itself.<br><br></p><p>Literature</p><p>Nikulins V., 2014. <em>Geodynamic Hazard Factors of Latvia: Experimental data and Computational Analysis</em>. Baltic Journal of Modern Computing, 7 (1), 151 – 170.</p><p>Safronovs O.N., Nikulins V.G., 1999. <em>General seismic zoning of Latvia</em>. Latvian geology news, 6, 30 - 35. (In Latvian).</p><p>Nikulin V., 2011. <em>Assessment of the seismic hazard in Latvia. Version of 2007 year</em>. RTU science articles. Materials Science and Applied Chemistry, 1 (24), 110 – 115.</p>

scholarly journals Magnetic effects due to earthquakes and underground explosions: a review

1997 ◽  
Vol 40 (2) ◽  
Author(s):  
V. V. Surkov ◽  
V. A. Pilipenko
Keyword(s):  
Magnetic Induction ◽  
Geomagnetic Field ◽  
Seismic Waves ◽  
Physical Nature ◽  
Earth’S Crust ◽  
Magnetic Effects ◽  
Tsunami Detection ◽  
Electromagnetic Effects ◽  
Earth's Crust ◽  
Theoretical Results

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.

scholarly journals System for Collecting, Processing, Visualization, and Storage of the MT-Monitoring Data

Data ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 99 ◽  
Author(s):  
Elena Bataleva ◽  
Anatoly Rybin ◽  
Vitalii Matiukov
Keyword(s):  
Practical Importance ◽  
Active Regions ◽  
Tien Shan ◽  
Earth’S Crust ◽  
Management Tool ◽  
Research Station ◽  
Depth Range ◽  
Integrated Monitoring ◽  
Geodynamic Processes ◽  
Earth's Crust

On the basis of the Research Station of the Russian Academy of Sciences in Bishkek, a unique scientific infrastructure—a complex geophysical station—is successfully functioning, realizing a monitoring of geodynamic processes, which includes research on the network of points of seismological, geodesic, and electromagnetic observations on the territory of the Bishkek Geodynamic Proving Ground located in the seismically active zone of the Northern Tien Shan. The scientific and practical importance of monitoring the geodynamical activity of the Earth’s crust takes place not only in seismically active regions, but also in the areas of the location of particularly important objects, mining, and hazardous industries. Therefore, it seems highly relevant to create new software and hardware to study geodynamic processes in the earth’s crust of seismically active zones, based on integrated monitoring of the geological environment in the widest possible depth range. The use of modern information technology in such studies provides an effective data management tool. The considering system for collecting, processing, and storing monitoring electromagnetic data of the Bishkek geodynamic proving ground can help overcome the scarcity of experimental data in the field of Earth sciences.

scholarly journals Assessing the Spatial and Spatio-Temporal Distribution of Forest Species via Bayesian Hierarchical Modeling

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 573 ◽  
Author(s):  
Óscar Rodríguez de Rivera ◽  
Antonio López-Quílez ◽  
Marta Blangiardo
Keyword(s):  
Hierarchical Modeling ◽  
Temporal Distribution ◽  
Short Term ◽  
Distribution Models ◽  
Address Climate Change ◽  
Bayesian Hierarchical ◽  
Temporal Models ◽  
Spatio Temporal ◽  
The Relationship

Climatic change is expected to affect forest development in the short term, as well as the spatial distribution of species in the long term. Species distribution models are potentially useful tools for guiding species choices in reforestation and forest management prescriptions to address climate change. The aim of this study is to build spatial and spatio-temporal models to predict the distribution of four different species present in the Spanish Forest Inventory. We have compared the different models and showed how accounting for dependencies in space and time affect the relationship between species and environmental variables.

scholarly journals Local seismicity alterations in the South Yakutia mining region due to the technogenic impact on its geological environment

2018 ◽  
Vol 56 ◽  
pp. 04019
Author(s):  
Nikolay Grib ◽  
Valery Imaev ◽  
Galina Grib ◽  
Lyudmila Imaeva ◽  
Igor Kolodeznikov
Keyword(s):  
Indirect Effects ◽  
Earth’S Crust ◽  
Seismic Events ◽  
Geological Environment ◽  
The South ◽  
Near Surface ◽  
Earthquake Energy ◽  
Technogenic Impact ◽  
Earth's Crust ◽  
The Impact

Impulse loads, arising due to the high natural seismicity of the South Yakutia region, exercise both direct and indirect effects on the upper part of the Earth's crust during industrial explosions. The direct effects result from nonlinear displacements caused by the blast wave and the subsequent formation of new disturbances. The indirect effects arise due to the activation of structural elements along geological contacts, leading to the emergence of technogenic seismicity foci. The foci of induced seismicity are either confined to the blast points, or located along the tectonic structures crossing quarry fields. The technogenic impact on the geological environment transforms the independent local seismic process, since explosions trigger a chain of local seismic events. The near-surface layers of the Earth's crust become activated in the area of dynamic influence of active faults. Under the influence of explosions, both the number of seismic events and the average level of released energy alter. Impulse loads on the geological environment lead to a spatial redistribution of the foci of low-energy (K <7) earthquakes. The main form of the geodynamic development of seismogenic faults is the movement of their sides in the form of mutual “slippage”. Seismic events are manifested only when the aforementioned form of deformation is impossible or difficult to develop, in other words, when the stress-state areas of the Earth's crust develop. Therefore, the shaking impact of blasts can be considered as a factor contributing to the predominance of aseismic forms of fault motion in the form of smooth slippage of their sides. In conclusion, the impact of industrial blasts can not only activate faults around the mining area, but also have an unloading effect on the foci of seismic hazard forming in the interior, i.e. the redistribution of earthquake energy in terms of reducing earthquake energy class.

scholarly journals THE SAMOTHRACE EARTHQUAKE OF MAY 2014 AND THE DISPLACEMENTS ESTIMATIONS USING PERMANENT GPS STATIONS DATA

2017 ◽  
Vol 50 (3) ◽  
pp. 1545 ◽  
Author(s):  
S. Bitharis ◽  
A. Fotiou ◽  
C. Pikridas ◽  
D. Rossikopoulos ◽  
S. Pavlides ◽  
...  
Keyword(s):  
Strong Earthquake ◽  
Satellite Observations ◽  
Earth’S Crust ◽  
Seismic Events ◽  
Aegean Area ◽  
The North ◽  
North Aegean ◽  
Geometrical Information ◽  
Gps Networks ◽  
Earth's Crust

The contribution of GPS networks in monitoring seismic events is important because they can provide a direct geometrical information on the Earth's crust using satellite observations In this study position displacements of permanent GPS stations are determined due to intense seismic events in the North Aegean area after the strong earthquake on May 24, 2014. The horizontal coseismic displacements for the Samothrace Island were estimated at 9.4 cm and for Lemnos Island at 5.2 cm respectively. A study period of seven days was enough to show that the deformation evolved into two days.

scholarly journals Geodynamics of the territory of Аrmenia based on the results of comprehensive observations

2019 ◽  
Vol 1 (1) ◽  
pp. 101-109
Author(s):  
Romela Pashayan ◽  
Levon Harutyunyan ◽  
Kristina Tovmasyan
Keyword(s):  
Seismic Data ◽  
Mineral Waters ◽  
Earth’S Crust ◽  
Seismic Events ◽  
The Past ◽  
Geodynamic Processes ◽  
Earth's Crust ◽  
Main Components ◽  
Increased Activity ◽  
Vertical Deformations

The geodynamics of the earth’s crust in the territory of Armenia is given according to seismic data, deformographic measurements, hydro geodynamic observations of the groundwater level, and geochemistry of mineral waters in the central part of the region. The map of the epicenters of earthquakes over the past three years includes stressed sections (concentration of earthquake epicenters) of the earth’s crust with increased activity geodynamic processes. Based on the results of the registration of deformations of two directions, the values of areal, volumetric, and vertical deformations are calculated. Variations in the water level in hydro geodynamic wells were obtained due to seismic events; the amplitudes of the variations depend on the magnitude of the earthquake, the distance from the epicenter, and the magnitude of the calculated deformation of the earth’s crust. The main components of the chemical composition of mineral waters (CL, HCO3, SO4, Mg), gas - CO2, and Ph in comparison with seismicity and other geodynamic processes of the earth’s crust.

Sign in / Sign up

Export Citation Format

Share Document