scholarly journals Temporal variation of seismic parameters in the western part of the India-Eurasia plate collision zone

2011 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
Ioannis Baskoutas ◽  
George Popandopoulos ◽  
Prasanta Chingtham
Keyword(s):  
Seismic Hazard ◽  
Temporal Variation ◽  
Strong Earthquake ◽  
Earthquake Forecasting ◽  
Target Area ◽  
Origin Time ◽  
Seismic Parameters ◽  
Strong Earthquakes ◽  
Mean Values ◽  
North West

We examined the temporal seismicity variation in the north-west Himalayas and the adjacent regions in relation to strong earthquake occurrences in the period 1970-2010. The aim was to promote seismic hazard assessment and to show the possibilities of strong earthquake forecasting by means of the FastBEE computer tool. The temporal variation of the seismicity is expressed in terms of three basic seismic parameters: the logarithm of the number of earthquakes logN, the seismic energy released in the mode logE2/3 and the b-value of the earthquake magnitude-frequency distribution expressed by the Gutenberg-Richter relation. Significant changes to relative mean values, forming consecutive relative minima and maxima, of the obtained temporal variation series of the seismicity parameters can be considered anomalies. These anomalies were investigated before strong (magnitude Mw≥5.6.) earthquake occurrences and were successfully correlated with 12 strong earthquakes. The mean time of the duration of the anomalies before the origin time of the impending earthquake were estimated to be equal to 3.3±1.3 years. We conclude that, in the region under study, the established correlations can be useful for the intermediate-term forecasting of strong earthquakes and that the continuous monitoring of the temporal evolution of seismicity by means of the FastBEE tool can contribute to the evaluation of the seismic hazard status in a target area. The available earthquake data and the results obtained indicate that after the beginning of 2006, the temporal variation of the seismicity does not present clear prognostic anomalies. This behavior is compatible with the absence of earthquakes with a magnitude of Mw 6.0 or more in the area examined.

scholarly journals Qualitative precursory pattern before several strong earthquakes in Greece.

2016 ◽  
Vol 47 (3) ◽  
pp. 1061
Author(s):  
I. Baskoutas ◽  
G. Papadopoulos
Keyword(s):  
Temporal Variation ◽  
Continuous Monitoring ◽  
B Value ◽  
Earthquake Catalogue ◽  
Earthquake Parameters ◽  
Seismic Parameters ◽  
Strong Earthquakes ◽  
Mean Values ◽  
Seismicity Pattern ◽  
Time Period

The temporal variation of the seismicity, based on the analysis of three seismic parameters i.e., number of earthquakes, b-value and energy released, were investigated before several strong earthquakes occurrence in Greece the time period 2000-2008. The seismic parameters estimates were obtained by the means of new tool, suited to analyze earthquake catalogue, and visualize their spatio-temporalvariation behaviour. The seismic data used were taken from the earthquake catalogue of the Geodynamic Institute of National Observatory of Athens, Greece. The obtained temporal variation series shows significant changes around their relative mean values, which specific phases can be related to the strong earthquakes preparation stages. This relation shows remarkable temporal regularity so that itcan be establish considered as a precursor seismicity pattern. These results suggest that identification of this behaviour, by the continuous monitoring of the temporal variation of the seismic parameters, can contribute to the assessment of the current seismic hazard and to the impending strong earthquake parameters evaluation, in a given area.

scholarly journals New tool for the spatio-temporal variation analysis of seismic parameters

2009 ◽  
Vol 9 (3) ◽  
pp. 859-864 ◽  
Author(s):  
G. A. Papadopoulos ◽  
I. Baskoutas
Keyword(s):  
Temporal Variation ◽  
Seismic Energy ◽  
B Value ◽  
Research Tool ◽  
Earthquake Activity ◽  
Seismic Parameters ◽  
Mean Values ◽  
Seismicity Parameters ◽  
Spatio Temporal ◽  
New Research

Abstract. In this paper a new research tool called FastBEE (Fast Estimation of Expected Big Earthquake) is proposed, for the analysis of three basic seismic parameters, (the number of earthquakes N, b-value, and the seismic energy released in the form logE2/3), in order to examine their spatio-temporal variation behavior. The developed research tool is suited to analyze earthquake catalogs and it comprise new interactive visualization techniques for the exploration of the results. The tool was tested in several seismic active areas of the Hellenic territory and a case study of its applicability is presented. It is observed that the results of the seismicity parameters analysis show a clear temporal fluctuation, with respect to their mean values. Such a behavior can be interpreted as the result of the geodynamic process acting in the region. In several cases the observed significant changes can be related to strong earthquakes, so that they can be considered as precursor indicating the preparation stage for an impending strong earthquake activity.

scholarly journals Active faults of the Kerch’s Peninsula: new results

2019 ◽  
Vol 488 (4) ◽  
pp. 408-412
Author(s):  
А. N. Ovsyuchenko ◽  
R. N. Vakarchuk ◽  
A. M. Korzhenkov ◽  
A. S. Larkov ◽  
А. I. Sysolin ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Strong Earthquake ◽  
Late Holocene ◽  
Active Fault ◽  
Active Faults ◽  
Fault Zones ◽  
Strong Earthquakes ◽  
Earthquake Sources ◽  
Kerch Peninsula ◽  
Seismotectonic Model

In the paper there are results of a recent study of the active faults in the Kerch Peninsula. There was compiled a Map of Active Faults - sources of the strong earthquakes occurred in Late Holocene. The map is a regional seismotectonic model of strong earthquake sources - detailed basis for a spatial prognosis of the seismic hazard. Results of the study show that the Kerch Peninsula demonstrates signs of the classical morphostructures, and a morphology of the modern peninsula contours is caused by the large active fault zones.

System-analytical method of strong earthquake-prone areas recognition

2021 ◽  
Author(s):  
Boris Dzeboev ◽  
Alexei Gvishiani ◽  
Boris Dzeranov
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Analytical Method ◽  
Strong Earthquake ◽  
Subduction Zones ◽  
Seismic Hazard Assessment ◽  
Hazard Identification ◽  
Strong Earthquakes ◽  
Weak Earthquakes ◽  
High Seismicity

<p>Proper seismic hazard assessment is the most important scientific problem of seismology, and geophysics in general. With the development of the world economy, the importance of the problem grows and acquires global significance.</p><p>Strong earthquakes (M ≥ M<sub>0</sub>, M<sub>0</sub> is the magnitude threshold starting from which earthquakes in the studied region are considered strong), as a rule, do not occur over the entire territory of the seismic region. Accordingly, the recognition of areas prone to future strong earthquakes is an urgent fundamental direction in research on the assessment of seismic hazard. Identification of potentially high seismicity zones in seismically active regions is important from both theoretical, and practical points of view. The currently available methods for recognition of high seismicity zones do not allow repeatedly correcting their results over time due to the invariability of the used set of recognition objects. In this work, a new system-analytical approach FCAZ (Formalized Clustering And Zoning) to the problem has been created. It uses the epicenters of rather weak earthquakes (M ≥ M<sub>R</sub>, M<sub>R</sub> is a certain magnitude threshold of weak earthquakes) as objects of recognition. This makes it possible to develop the recognition result of zones with increased seismic hazard after the appearance of new earthquake epicenters. The latter makes FCAZ a method of systems analysis.</p><p>The system-analytical method for analyzing geophysical data developed by the authors has led to the successful recognition of areas prone to the strongest, strong, and most significant earthquakes on the continents of North, and South America, Eurasia, and in the subduction zones of the Pacific Rim. At the same time, in particular, for the classical approach of strong earthquake-prone areas recognition EPA (Earthquake-Prone Areas), a new paradigm for recognition of high seismicity disjunctive nodes, and lineament intersections with training by one “reliable” class was created in the work.</p><p>In the regions studied in this work, FCAZ zones occupy a relatively small area compared to the field of general seismicity – 30% – 40% of the area of all seismicity, and 50% – 65% of the area where earthquakes with M ≥ M<sub>R</sub> occur. This illustrates the spatial nontriviality of the FCAZ results obtained in this work. The results of the work also show that weak seismicity can actually “manifest” the properties of geophysical fields, which in the classical EPA approach are used directly as characteristics of recognition objects (disjunctive nodes or intersections of the axes of morphostructural lineaments).</p><p>The reported study was funded by RFBR, project number 20-35-70054 «Systems approach to recognition algorithms for seismic hazard assessment».</p>

scholarly journals SEISMIC HAZARD OF GANJA CITY

2014 ◽  
Author(s):  
З.Г. Аллахвердиева
Keyword(s):  
Seismic Hazard ◽  
Empirical Formula ◽  
Seismic Risk ◽  
Strong Earthquake ◽  
Seismic Effect ◽  
Point Of View ◽  
Focal Points ◽  
Strong Earthquakes ◽  
Industrial Center

Изучение сейсмического риска города Гянджа на наш взгляд имеет большое значение, так как этот город является вторым промышленным центром республики. Для имеющихся очагов сильных землетря- сений в районе г. Гянджи на основе магнитуды вероятного максимально сильного землетрясения по эмпирической формуле М. В. Шебалина для разных глубин и расстояний был вычислен сейсмический эффект. Результаты показывают, что очаги, расположенные на районе Гек-гель и Зурнабад с сейсмической точки зрения наиболее опасные. Вероятность создания опасного сейсмического эффекта от Дашкесанских, Ге- дебекских и Келбаджарских очагов мала Investigation of seismic risk of Ganja city in our opinion is of a great importance, since this city is the second industrial center of the country. The seismic effect was calculated for existing sources of strong earthquakes in the area of Ganja city -based on the magnitude of probable maximum strong earthquake using the empirical formula of M. V. Shebalin for various depths and distances. The results show that focal points located in the areas Gek-gel and Zurnabad are most hazardous from seismic point of view. Probability of hazardous seismic effect occurrence from Dashkesan, Gedebeksk, Kelbadzhar focal points is small

scholarly journals SPACE REGULARITY MANIFESTATION OF THE TEMPORAL VARIATION OF SEISMIC PARAMETERS: POSSIBILITY FOR THE STRONG SEISMIC ACTIVITY ASSESSMENT

2017 ◽  
Vol 43 (4) ◽  
pp. 2125
Author(s):  
George Popandopoulos ◽  
I. Baskoutas
Keyword(s):  
Temporal Variation ◽  
Seismic Energy ◽  
B Value ◽  
Data Sets ◽  
Earthquake Activity ◽  
Seismic Parameters ◽  
Strong Earthquakes ◽  
Seismic Catalogue ◽  
Local Areas ◽  
Earthquake Predictions

In the present work the detailed analysis of the space-time variation, of the seismic energy released and b-value was performed, in order to study the space regularity manifestation of the temporal variation of seismic parameters, to test the reliability of the results and to compare the obtained temporal profiles in relation to the strong earthquake activity. The study was carried out in the subduction zone along the western part of the Hellenic trench arc system. The earthquakes data, witch occurs in the five adjacent local areas in the period 1980 -2007 were used. The reliability of the results is tested positively for “internal” dubiety, against independent seismic data sets from adjacent local areas, being in common the processing method, and the properties of seismic catalogue. It was found that in the majority of the cases (23 of 32) the significant temporal variation changes, considered as anomalies, can be related to the preparation process of the strong earthquakes Ms>5.7, acting as intermediate term precursors. Based on these findings the quality index of the successful intermediate term earthquake predictions reach up to 71.9%. It is observed that the temporal variation of the seismic energy released anomalies were time shifted in respect to the central areas, toward to N-NE and S-SE direction. Moreover it is found that the strong earthquakes occurrence also shows immigration, in respect to the central areas, along the concatenation of the adjacent local areas. These two observations may reveal the formation of a tectonic wave, in the broader area south of Zakynthos Island, Its velocity was estimated to be as 100 to 150 km/year

scholarly journals Precursory seismicity pattern before strong earthquakes in Greece

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Ioannis Baskoutas ◽  
George Anatoli Papadopoulos
Keyword(s):  
Temporal Variation ◽  
Seismic Hazard Assessment ◽  
Seismic Parameters ◽  
Strong Earthquakes ◽  
Seismicity Pattern ◽  
Time Period ◽  
Quantitative Characteristics ◽  
Precursory Seismicity ◽  
Remarkable Relation ◽  
Qualitative And Quantitative Characteristics

The temporal variation of seismicity, based on the retrospective analyses of three seismic parameters <em>i.e.</em>, number of earthquakes, bvalue and energy released, have shown significant changes. Their remarkable relation with strong earthquakes occurrence was formulated as a qualitative character precursory seismicity pattern, which were interpreted in terms of a strong earthquakes occurrence preparation phases. The main characteristic of this pattern is that permits the identification of two period of low and high probability for an earthquake occurrence, suggesting its utility in the current seismic hazard assessment, by the continuous monitoring of the temporal variation of the seismic parameters in a given area. This paper investigates the qualitative and quantitative characteristics of the proposed precursory seismicity pattern, before al strong earthquakes occurrence in Greece the time period 2000-2008.

Species composition and spatio-temporal variation of bycatch from mid-water trawlers operating in the Arabian Sea along north-west coast of India

2021 ◽  
Vol 43 ◽  
pp. 101692
Author(s):  
P. Abdul Azeez ◽  
Prathibha Rohit ◽  
Latha Shenoy ◽  
Ashok Kumar Jaiswar ◽  
Mini Raman ◽  
...  
Keyword(s):  
Species Composition ◽  
Temporal Variation ◽  
West Coast ◽  
Arabian Sea ◽  
North West ◽  
West Coast Of India ◽  
Spatio Temporal

Strong earthquake activity influenced by solar flare intensity

2021 ◽  
Author(s):  
Gerald Duma
Keyword(s):  
Solar Flares ◽  
Strong Earthquake ◽  
Temporal Variations ◽  
Seasonal Effect ◽  
Earthquake Activity ◽  
Strong Earthquakes ◽  
International Service ◽  
Earthquake Frequency ◽  
Magnetic Index ◽  
Magnetic Disturbances

&lt;p&gt;Based on the comprehensive earthquake catalogue USGS ( HYPERLINK&lt;span&gt;&amp;#160; &lt;/span&gt;https://earthquake.usgs.gov) the paper demonstrates that strong earthquake activity, seismic events with M&amp;#8805;6, exhibits a seasonal trend. This feature is the result of&lt;span&gt;&amp;#160; &lt;/span&gt;analyses of earthquake data for the N- and S- Earth Hemisphere in period 2010-2019. It can be shown also for single earthquake prone regions as well, like Japan, Eurasia, S-America.&lt;/p&gt;&lt;p&gt;Any seasonal effect suggests an external influence. In that regard, one can think also of a solar-terrestrial effect, that is suggested already in several studies (e.g&lt;span&gt;&amp;#160; &lt;/span&gt;M.Tavares, A.Azevedo, 2011; D.A.E. Vares, M.A.Persinger,2014; G.Duma, 2019). This assumption leads to the question: Which dynamic process can cause a trigger effect for strong earthquakes in the Earth's lithosphere.&lt;/p&gt;&lt;p&gt;In this study the intensity of solar flares and the resulting radiation, the solar wind, towards the Earth was taken into account. An appropriate parameter which has been regularity measured and reported for many decades and which reflects the intensity of solar radiation is the magnetic index Kp. It is measured at numerous geomagnetic observatories and describes the magnetic disturbances in nT within 3 hour intervals, respectively. Averages of all the measured 3-hour values are then published as Kp, therefore considered a planetary parameter (International Service of Geomagnetic Indices ISGI,France).&lt;/p&gt;&lt;p&gt;The temporal variations of strong earthquake activity over 10 years and their energy release was compared with the above mentioned index Kp. Actually, a distinct correlation between the two quantities, Kp and earthquake frequency, resulted in cases of different regions as well as globally.&amp;#160;Another essential result of the study is that maxima of Kp preceed those of earthquake activity by about 60 to 80 days in most cases. The mechanism has not yet been modeled satisfactorily.&lt;/p&gt;

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