scholarly journals Recent 2005-2006 strong seismic activity in Greece under the aspect of seismicity parameters temporal variation analysis

2018 ◽  
Vol 40 (3) ◽  
pp. 1055 ◽  
Author(s):  
I. Baskoutas ◽  
G. A. Papadopoulos ◽  
V. Karakostas ◽  
E. Papadimitriou
Keyword(s):  
Temporal Variation ◽  
Temporal Pattern ◽  
B Value ◽  
Mean Value ◽  
Northwestern Part ◽  
Cumulative Number ◽  
Seismicity Parameters ◽  
Hellenic Arc ◽  
Adequate Data ◽  
Event Occurrence

Recent strong seismic excitation (2005-2006), which occurred at the northwestern part of the Hellenic arc and north ofSamos Island close to the coasts of the Asia Minor, is investigated under the aspect of temporal variation seismicity profile of activated seismic zones. Seismicity profile is constructed by the means ofther FastBEE analysis introduced recently. Seismicity parameters considered in this study are b-value, energy releasee in the form logE2/3 and the quantity logNofthe cumulative number of events, in the examined area. Due to homogeneity and completeness reasons, the earthquakes with magnitudes Mi>3.0 since 1990 from the earthquake catalogue of the Geodynamic Institute of the National Observatory of Athens, is used to perform the present analysis in both areas. Temporal variation profiles for both areas show a remarkable fluctuation around their mean value and specifically above the limits of the calculated standard errors behaviour forming a temporal pattern, which can be attributed to earthquake preparation process. In this temporal pattern, b value, which is related to the seismogenic process in many previous studies all over the world shows a tendency to increase and then to decrease before the occurrence of a strong earthquake, and at the same time the quantity logE 3 shows a tendency to decrease and then to increase before the strong event occurrence Mis identification of such a clear pattern for a period of time can be attributed to the lack of adequate data.

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 Acoustic Emission Monitoring of the Turin Cathedral Bell Tower: Foreshock and Aftershock Discrimination

2020 ◽  
Vol 10 (11) ◽  
pp. 3931 ◽  
Author(s):  
Amedeo Manuello Bertetto ◽  
Davide Masera ◽  
Alberto Carpinteri
Keyword(s):  
Structural Integrity ◽  
Regional Scale ◽  
Acoustic Emissions ◽  
B Value ◽  
Masonry Building ◽  
Cumulative Number ◽  
Value Analysis ◽  
Integrity Assessment ◽  
Static And Dynamic Analysis ◽  
Bell Tower

Historical churches, tall ancient masonry buildings, and bell towers are structures subjected to high risks due to their age, elevation, and small base-area-to-height ratio. In this paper, the results of an innovative monitoring technique for structural integrity assessment applied to a historical bell tower are reported. The emblematic case study of the monitoring of the Turin Cathedral bell tower (northwest Italy) is herein presented. First of all, the damage evolution in a portion of the structure localized in the lower levels of the tall masonry building is described by the evaluation of the cumulative number of acoustic emissions (AEs) and by different parameters able to predict the time dependence of the damage development, in addition to the 3D localization of the AE sources. The b-value analysis shows a decreasing trend down to values compatible with the growth of localized micro and macro-cracks in the portion of the structure close to the base of the tower. These results seem to be in good agreement with the static and dynamic analysis performed numerically by an accurate FEM (finite element model). Similar results were also obtained during the application of the AE monitoring to the wooden frame sustaining the bells in the tower cell. Finally, a statistical analysis based on the average values of the b-value are carried out at the scale of the monument and at the seismic regional scale. In particular, according to recent studies, a comparison between the b-value obtained by AE signal analysis and the regional activity is proposed in order to correlate the AE detected on the structure to the seismic activity, discriminating foreshock, and aftershock intervals in the analyzed time series.

Smart Geospatial System Design for Real-Time Risk Assessment at the Highly Active Area of the Ionian Islands, Greece

2020 ◽  
Author(s):  
Evelina Kotsi ◽  
Spyridon Mavroulis ◽  
Michalis Diakakis ◽  
Emmanuel Vassilakis ◽  
Efthymios Lekkas
Keyword(s):  
Risk Assessment ◽  
Real Time ◽  
Initial Step ◽  
Northwestern Part ◽  
Civil Protection ◽  
Ionian Islands ◽  
Highly Active ◽  
Hellenic Arc ◽  
Geospatial Database ◽  
Risk Areas

<p>The Ionian Islands are located in the northwestern part of the Hellenic Arc and constitute one of the most seismically active areas in the Mediterranean. Building a geospatial database including all the available geo-information layers was the initial step for identifying and delineating the earthquake-related environmental effects by using various mapping algebra techniques and algorithms. Landslide, liquefaction and tsunami related inventories were created. Real time recording network of sensors such as meteorological instruments, seismographs, accelerometers etc was designed to trans pond data telemetrically and feed a dynamically interactive geodatabase, which in turn act as a smart tool for declaring an area as vulnerable to a specific hazard. The abovementioned approach can contribute to the reduction of the consequences after a disastrous event, as it will provide useful information to the civil protection authorities for increased alertness during an ongoing threat.</p><p>The identification of the risk areas by using various methods has become significant in recent years due to the fact that among others it serves as a valuable tool for revealing and highlighting sites of significant hazards. In this study we present a smart tool, specially developed for recording and taking under consideration any changing parameters that affect the susceptibility of an area to any of the studied geo-hazards and highlight it on a digital real time updateable map.</p>

scholarly journals LONG TEMPORAL VARIATION OF SEISMIC PARAMETERS FOR SEISMIC PATTERNS IDENTIFICATION IN GREECE

2004 ◽  
Vol 36 (3) ◽  
pp. 1362
Author(s):  
I. Baskoutas ◽  
G. Panopoulou ◽  
G. Papadopoulos
Keyword(s):  
Temporal Variation ◽  
Seismic Activity ◽  
Time Window ◽  
Energy Parameter ◽  
Aegean Sea ◽  
B Value ◽  
Seismogenic Zone ◽  
Earthquake Catalog ◽  
Estimation Model ◽  
Seismic Parameters

A new approach of detailed spatio-temporal variation analysis of seismic data is proposed by means of FastBEE (Fast estimation of Big Expected Earthquake) aiming at the regional monitoring of seismic activity for premonitory seismic patterns identification. For the investigation of temporal variation, a set of seismic parameters is used, like the logarithm of the number of earthquakes logN, estimates of 6-value obtained by the maximum likelihood estimation model, time clustering of seismic activity AR(t) and of energy released EM, since they can be considered as precursory seismological indicators. Earthquake catalog data, used in this approach, were elaborated in order to construct the time series for each parameter within a time window, large enough, as to guarantee statistical meaningful result. The Hellenic trench-arc region under investigation is chosen in the basis of its seismotectonic characteristics, in relation to the spatial extent of the seismogenic zone. The tools were tested, for long temporal variation features in the Ionian Islands Sea and the North Aegean Sea regions and its successful applicability is presented. The rise of irregularity, along these temporal profiles, was formulated in specific quantitative premonitory seismic pattern. In most of the cases, FastBEE premonitory pattern found shows significant changes from the background values of each parameter. Parameter logN shows a valley form curve, which start to increase before the expected earthquake occurrence, as well as the energy parameter E273, while b-value temporal estimates are forming a mountain shape curve, before the occurrence of a big earthquake. Instead, parameter ÙR(t) present a rapid fluctuation, without any kind of premonitory character

scholarly journals The Spatio-temporal Analysis of b-value in the Banda Arc, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012010
Author(s):  
Muhammad Bani Al-Rasyid ◽  
Mira Nailufar Rusman ◽  
Daniel Hamonangan ◽  
Pepen Supendi ◽  
Kartika Hajar Kirana
Keyword(s):  
Temporal Variation ◽  
Temporal Analysis ◽  
B Value ◽  
Spatial And Temporal Variation ◽  
Tectonic Structure ◽  
Time Period ◽  
Banda Arc ◽  
Spatio Temporal ◽  
The Impact ◽  
Large Earthquakes

Abstract Banda arc is a complex tectonic structure manifests by high seismicity due to the collision of a continent and an intra-oceanic island arc. Using the relocated earthquakes data from ISC-EHB and BMKG catalogues from the time period of 1960 to 2018, we have conducted a spatial and temporal variation of b-value using the Guttenberg-Richter formula in the area. Our results show that the spatial distribution of low b-values located in the south of Ambon Island and southeast of Buru Island. On the other hand, the temporal variation of b-value shows a decrease in the northern part of the Banda sea probably high potential to produce large earthquakes in the future. Therefore, further mitigation is needed to minimize the impact of earthquakes in the area.

SOMATOMEDIN A AND B IN SERUM FROM NEONATES, THEIR MOTHERS AND CORD BLOOD

1977 ◽  
Vol 85 (3) ◽  
pp. 636-643 ◽  
Author(s):  
H. Svan ◽  
K. Hall ◽  
M. Ritzén ◽  
K. Takano ◽  
A. Skottner
Keyword(s):  
Birth Weight ◽  
Cord Blood ◽  
Pregnant Women ◽  
Reference Group ◽  
B Value ◽  
Mean Value ◽  
Radioreceptor Assay ◽  
B Values ◽  
Positive Correlation ◽  
The Mean

ABSTRACT Somatomedin A by radioreceptor assay and somatomedin B by radioimmunoassay were measured in serum from women immediately after parturition and from their newborns. The mean levels of somatomedin A in both mothers (0.54 U/ml) and infants (0.50 U/ml) were significantly decreased compared to a reference group consisting of 21 non-pregnant women (0.91 U/ml). There was no difference between the mothers and their children. The mean somatomedin B value in serum from the mothers (63.9 μg/ml) was above that found in non-pregnant women (19.2 μg/ml) and the mean value in cord blood and serum from the infants (7.1 μg/ml) was below it. A positive correlation was noted between somatomedin A and B in cord blood; r = 0.78. The combined somatomedin A and B values in cord blood were positively correlated to birth weight (r = 0.51, P < 0.05).

scholarly journals Investigation of Hydrokinetic Properties of Hydrogeologic Units of Sandy Lithofacies: A Case Study of Parts of Enugu State, Southeastern Nigeria

2020 ◽  
Author(s):  
Johnson Cletus Ibuot ◽  
Emmanuel T. Omeje ◽  
Daniel Nnemeka Obiora
Keyword(s):  
Mean Value ◽  
Northwestern Part ◽  
Southeastern Nigeria ◽  
Contour Maps ◽  
Flow Units ◽  
Electrical Sounding ◽  
Enugu State ◽  
Hydraulic Flow Units ◽  
Very High

Abstract Vertical electrical sounding employing schlumberger electrode configuration was carried out in thirty locations across some parts of Enugu state, to investigate the hydrokinetic properties of hydrogeologic units of the study area. The result shows that resistivity and thickness of aquifer ranges from 27.3 to 59569.0 Ωm and 23.3 to 242.1 m respectively. Permeability and fractional porosity values range from 4531.254 to 74006.76 mD and 0.026 to 0.159. AQI having a mean value of 13.5451 µm range from 6.809 to 52.976 µm. FZI and HFU values range from 37.582 to 1962.074 µm and 18 to 26 respectively. Contour maps were generated from the results to visualize the variations of the hydrokinetic properties across the study area. From the contour maps, southern part of the study area was identified to be characterized with high AQI, FZI and HFU with northwestern part and a small proportion along the southwestern part identified as areas with low AQI, FZI and HFU. HFU along the study area was observed to be fractionated into nine distinct properties (HFU 18, HFU 19, HFU 20, HFU 21, HFU 22, HFU 23, HFU 24, HFU 25, and HFU 26) with HFU 19 and HFU 20 dominating the area. The results from the nine hydraulic flow units based on flow zone indicator cut off values (Log FZI ˃ 0.25) shows that the reservoir quality is very high.

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.

Microearthquake survey of Tehran region, Iran

1976 ◽  
Vol 66 (5) ◽  
pp. 1713-1725
Author(s):  
A. Hedayati ◽  
J. L. Brander ◽  
M. Berberian
Keyword(s):  
B Value ◽  
Seismic Intensity ◽  
Ground Movement ◽  
Cumulative Number ◽  
The South ◽  
Fault Plane Solutions ◽  
Tehran Region ◽  
Risk Curve ◽  
Major Fault ◽  
The City

abstract A short microearthquake survey of part of north central Iran around the city of Tehran made late in 1974, showed that earthquakes occurred at the rate of 21.37 events per day. Epicentral locations for 37 events, using a geometric ray path technique, show the observed activity to be concentrated in three principal groups: two associated with the known major fault on the south flank of the Alborz mountain, while the third constitutes a previously unrecognized lineation passing very close to the city of Tehran. The cumulative number versus magnitude relation was obtained from the study of 198 well-recorded events. The slope of the linear portion of the relation (b value), −0.79, agrees well with the value of −0.86 determined from the USCGS records of larger earthquakes between 1961 and 1973. Composite fault-plane solutions were made for each of the three principal groups, showing predominantly strike-slip movement with a thrust component on the south of the Alborz and thrusting on the new lineation. The seismic intensity risk curve calculated for the area shows that the city of Tehran can expect ground movement of MM intensity VII every 12 years, and intensity IX every 350 years.

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