scholarly journals On dynamics of seismicity simulated by the models of blocks-and-faults systems

1997 ◽  
Vol 40 (5) ◽  
Author(s):  
A. I. Gorshkov ◽  
V. I. Keilis-Borok ◽  
I. M. Rotwain ◽  
A. A. Soloviev ◽  
I. A. Vorobieva
Keyword(s):  
Numerical Simulation ◽  
Earthquake Prediction ◽  
Driving Forces ◽  
Block Structure ◽  
Seismicity Patterns ◽  
Strong Earthquakes ◽  
Structure Dynamics ◽  
Prediction Algorithms ◽  
The Media

The major results obtained by numerical simulation of block structure dynamics are juxtaposed and analysed: the possibilities to reconstruct tectonic driving forces from territorial distribution of seismicity, clustering of earthquakes in the model, and dependence of the occurrence of strong earthquakes on fragmentation of the media, and on rotation of blocks. These results show that modelling of block structure dynamics is a useful tool to study relations between the geometry of faults and block movements and earthquake flow, including premonitory seismicity patterns, to test the existing earthquake prediction algorithms, and to develop new ones.

scholarly journals Transformation of frequency-magnitude relation prior to large events in the model of block structure dynamics

2008 ◽  
Vol 15 (1) ◽  
pp. 209-220 ◽  
Author(s):  
A. Soloviev
Keyword(s):  
Normal State ◽  
Block Structure ◽  
B Value ◽  
Fault Zones ◽  
Earthquake Catalogue ◽  
Separate Analysis ◽  
Strong Earthquakes ◽  
Structure Dynamics ◽  
Time Periods ◽  
Frequency Magnitude

Abstract. The b-value change in the frequency-magnitude (FM) distribution for a synthetic earthquake catalogue obtained by means of the model of block structure dynamics has been studied. The catalogue is divided into time periods preceding strong earthquakes and time periods that do not precede strong earthquakes. The separate analysis of these periods shows that the b-value is smaller before strong earthquakes. The similar phenomenon has been found also for the observed seismicity of the Southern California. The model of block structure dynamics represents a seismic region as a system of perfectly rigid blocks divided by infinitely thin plane faults. The blocks interact between themselves and with the underlying medium. The system of blocks moves as a consequence of prescribed motion of the boundary blocks and of the underlying medium. As the blocks are perfectly rigid, all deformation takes place in the fault zones and at the block base in contact with the underlying medium. Relative block displacements take place along the fault zones. Block motion is defined so that the system is in a quasistatic equilibrium state. The interaction of blocks along the fault zones is viscous-elastic ("normal state") while the ratio of the stress to the pressure remains below a certain strength level. When the critical level is exceeded in some part of a fault zone, a stress-drop ("failure") occurs (in accordance with the dry friction model), possibly causing failure in other parts of the fault zones. These failures produce earthquakes. Immediately after the earthquake and for some time after, the affected parts of the fault zones are in a state of creep. This state differs from the normal state because of a faster growth of inelastic displacements, lasting until the stress falls below some other level. This numerical simulation gives rise a synthetic earthquake catalogue.

scholarly journals Strong earthquakes can be predicted: a multidisciplinary method for strong earthquake prediction

2003 ◽  
Vol 3 (6) ◽  
pp. 703-712 ◽  
Author(s):  
J. Z. Li ◽  
Z. Q. Bai ◽  
W. S. Chen ◽  
Y. Q. Xia ◽  
Y. R. Liu ◽  
...  
Keyword(s):  
Earthquake Prediction ◽  
Strong Earthquake ◽  
Low Frequency ◽  
Abnormal Behavior ◽  
Frequency Range ◽  
Strong Earthquakes ◽  
Physical Mechanisms ◽  
Innovative Methods ◽  
The World ◽  
Infrasonic Wave

Abstract. The imminent prediction on a group of strong earthquakes that occurred in Xinjiang, China in April 1997 is introduced in detail. The prediction was made on the basis of comprehensive analyses on the results obtained by multiple innovative methods including measurements of crustal stress, observation of infrasonic wave in an ultra low frequency range, and recording of abnormal behavior of certain animals. Other successful examples of prediction are also enumerated. The statistics shows that above 40% of 20 total predictions jointly presented by J. Z. Li, Z. Q. Ren and others since 1995 can be regarded as effective. With the above methods, precursors of almost every strong earthquake around the world that occurred in recent years were recorded in our laboratory. However, the physical mechanisms of the observed precursors are yet impossible to explain at this stage.

Modelling of Block-structure Dynamics: Parametric Study for Vrancea

1999 ◽  
Vol 156 (3) ◽  
pp. 395-420 ◽  
Author(s):  
A. A. Soloviev ◽  
I. A. Vorobieva ◽  
G. F. Panza
Keyword(s):  
Parametric Study ◽  
Block Structure ◽  
Structure Dynamics

Development and Application of Slow Crack Propagation of Polyethylene Based on Crack Layer Theory

2007 ◽  
Vol 345-346 ◽  
pp. 489-492 ◽  
Author(s):  
Byoung Ho Choi ◽  
Alexander Chudnovsky
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Crack Growth ◽  
Driving Forces ◽  
Slow Crack Growth ◽  
Layer Model ◽  
Elapsed Time ◽  
Simulation Based ◽  
Crack Layer

For explaining the SCG behavior of polyethylene, the crack layer theory is applied based on the description of two driving forces: crack and PZ. The relations between the speed of SCG, crack length and elapsed time are the most important characteristics of polyethylene resistance to crack propagation, or long-term brittle fracture. The crack layer model of slow crack growth in polyethylene is designed in such a way that it qualitatively reproduces the main features of the process indicated above and makes it possible to quantitatively match any pattern of step-wise crack growth. In this paper, the behavior of SCG of polyethylene is developed for numerical simulation based on the crack layer theory. Some parametric study and applications are addressed based on the developed simulation program.

Seismicity patterns before strong earthquakes in Greece

2009 ◽  
Vol 57 (2) ◽  
pp. 367-386 ◽  
Author(s):  
Vassilis Karakostas
Keyword(s):  
Seismicity Patterns ◽  
Strong Earthquakes

scholarly journals PHASE REARRANGEMENT IN LOCAL BALANCED HYDROGEOCHEMICAL SYSTEMS AS A OF FLUID EARTHQUAKE PRECURSORS MECHANISM OCCURRENCE

2019 ◽  
Vol 16 (33) ◽  
pp. 248-258
Author(s):  
A. U. ABDULLAEV
Keyword(s):  
Earthquake Prediction ◽  
Structural Relaxation ◽  
Earthquake Precursors ◽  
Strong Earthquakes ◽  
Major Earthquake ◽  
Time Period ◽  
Internal Phase ◽  
The World ◽  
Precursors Of Earthquakes ◽  
Hydrogeochemical System

Scientists all over the world are making tremendous efforts to solve the problem of earthquake prediction. Dozens of different phenomena and signs that could serve as precursors of earthquakes are found. But these effects were very unstable and had a mosaic character in the propagation of development and time. They appeared not always and not before every major earthquake. There are many cases where earthquakes occurred without the manifestation of any precursors. Such non-stationary phenomena do not allow formulating adequate strong earthquakes preparing models and their methods of predicting. Among well-studied and encouraging earthquake precursors, hydrogeodynamic and hydrogeochemical anomalies are considered to be the most promising, which has a sufficiently substantiated scientific background. In this class of precursors, the mechanism of their formation during the preparation of earthquakes remains debatable. There are several problems due to abnormal concentration sources and their transport during a little time period in the observation points. In the proposed work, it is proved that the main mechanism of the occurrence of exotic transient fluid anomalies is the interphase rearrangement in the local balanced hydrogeochemical system as a reaction to strong earthquakes factors preparing influence. The internal phase reorganization in the hydrogeochemical system is realized through structural relaxation as a result of the occurrence of rapid physicochemical reactions exchange.

scholarly journals Media support and its influence on the results of the referendum in Britain’s exit from the EU

2020 ◽  
pp. 102-114
Author(s):  
Yana Kybich
Keyword(s):  
European Union ◽  
Driving Forces ◽  
Political Process ◽  
British Society ◽  
The Political ◽  
The European Union ◽  
Binary Oppositions ◽  
The Media ◽  
The Uk ◽  
The Eu

June 2016 was marked by a landmark event - the so-called Brexit (literally from Britain’s exit ) – a referendum in which 52% of the population voted for the withdrawal of the United Kingdom from the European Union and only 48% - against. The significant changes that took place in the UK in the summer of 2016, finally split British society into those who are for and against leaving the European Union. The British media acted as a platform for political debates and discussions on the key issue of Britain’s stay in the EU. The most powerful media conglomerate, of course, had a decisive influence on the mood of those who voted, intensifying social polarization, which was reflected in the results of the fateful referendum. Elements of the British media played a key role in the debate over the referendum on the country’s membership in the European Union. The exit vote was influenced by a long campaign against the EU and against migration from EU countries. Throughout the campaign, virtually all media are in flagrant violation of journalistic standards of objectivity, fairness, and accuracy, becoming essentially propaganda bodies. The relevance of the study is due to the fundamental changes in British society related to the Brexit process, as well as the importance for politicians and the public of understanding public opinion and the media about Brexit. In addition, it is important to see how the view of Brexit has changed. It is necessary to find out the benefits, priorities and understanding of different scenarios, the driving forces behind these attitudes, and whether they change in response to statements and remarks by politicians and public figures. Britain’s withdrawal from the European Union is important for the whole world, as it affects the changing geopolitics of the whole of Europe. This topic is important for understanding the study of the political preferences of British society and the British media during the Brexit process. It can be stated unequivocally that both Brexit and the subsequent US election campaign in 2016 showed another example of skillful speculation in facts and figures, the successful creation and dissemination of unverified “viral information” through the media, which in the era of telecommunications has become a particularly effective tool for manipulation of public sentiment. The example of Brexit has demonstrated how to take the success of such campaigns to a new level, using all types of media (from traditional to electronic, including social networks), through which you can introduce into society binary oppositions that divide it, to introduce into the information space certain political figures, to popularize the necessary moods and slogans, to simplify the political process to the level of a show.

The Numerical Simulation of the Flow Field in the Underground Hydrocyclone

2013 ◽  
Vol 655-657 ◽  
pp. 470-475
Author(s):  
Jing Chang Wang ◽  
Fu Lai Guo ◽  
Meng Hua Wu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Field Distribution ◽  
Phase Distribution ◽  
Three Dimensional ◽  
Internal Flow ◽  
No Formation ◽  
The Media ◽  
Solid Liquid ◽  
Air Column

For preventing sand in underground oil, this paper structures a model of hydrocyclone with the inside cyclone and the outside one seriesing and describes how it works. By the TGrid procedures, the all of the hydrocyclone is meshed with the tetrahedral and the boundary conditions are determined. The methods of Three-dimensional numerical simulation in FLUENT are used to simulate the velocity field distribution, the pressure field distribution, the path lines of the separated medition characteristics of the separated medium and the phase distribution of the medium. The affect of the internal separated medition characteristics to the separated performance is analysed. Through the simulation, it is found that the spiral fin in the hydrocyclone can guide the fluid to produce a vortex flow to meet the purpose of separating the solid-liquid. There is no formation of the air column comparing with the conventional cyclone, so the internal flow field is more stable to conductive to the separation of the media. It provides a basis for the improvement of the cyclone.

Relationship between Strong Earthquakes and Activation of Deep Faults in Central Asia (Uzbekistan): Numerical Simulation of Stress Field Variations

Geotectonics ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 377-392
Author(s):  
I. U. Atabekov ◽  
T. U. Artikov ◽  
R. S. Ibragimov ◽  
T. L. Ibragimova ◽  
M. A. Mirzaev
Keyword(s):  
Numerical Simulation ◽  
Stress Field ◽  
Central Asia ◽  
Strong Earthquakes ◽  
Deep Faults
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