scholarly journals Analysis of Exponent K Based on “Share” Project Data and Its Implications on Importance Factors of En 1998-1

2021 ◽  
Author(s):  
Dejan Dragojevic ◽  
Radmila Salic ◽  
Zoran Milutinovic
Keyword(s):  
Seismic Activity ◽  
Active Regions ◽  
Expected Value ◽  
Single Parameter ◽  
Comparison Of Results ◽  
Hazard Curve ◽  
European Area ◽  
Vrancea Zone ◽  
National Studies ◽  
Project Data

Abstract This paper deals with seismic activity represented by a hazard curve through a single parameter – exponent k as given in EN 1998-1, as well as with its implications on importance factors. We have used the SHARE project dataset for calculation of exponent k for the wider European area and limited number of separate national studies for comparison of results since comparison to the SHARE results on the same dataset resulted with values of exponent k smaller by 1–1.5. The results indicate that recommended value of exponent k of 3 is rather an exception than expected value in seismically active regions, and that with the exclusion of Vrancea zone, for majority of Europe exponent k is well below assumed in EN 1998-1, which consequently indicate that importance factors for these locations should be larger than recommended in EN 1998-1.

Detections of Directional Dynamic Triggering in Intraplate Regions of the United States

2021 ◽  
Author(s):  
Vivian Tang ◽  
Kevin Chao ◽  
Suzan van der Lee
Keyword(s):  
United States ◽  
Surface Waves ◽  
Seismic Activity ◽  
Active Regions ◽  
The United States ◽  
North American Plate ◽  
Western Boundary ◽  
Eastern United States ◽  
Dynamic Triggering ◽  
The North

ABSTRACT We report tremor or local earthquake signals that occurred during the propagation of Love and Rayleigh waves from the 2012 Mw 8.6 Sumatra earthquake in three intraplate regions: Yellowstone, central Utah, and Raton basin (Colorado). These surface waves likely also dynamically triggered seismic activity along the western boundary of the North American plate, and did not trigger seismic activity in the central and eastern United States. We report additional potential dynamic triggering in the three aforementioned intraplate regions by surface waves from 37 additional large earthquakes, recorded between 2004 and 2017. These surface waves’ transient stresses generally appear to trigger tremor in seismically, volcanically, and hydrothermally active regions, such as Yellowstone, if the waves also arrive from favorable directions. These stresses do not appear to be decisive factors for triggering local earthquakes reported for the Raton basin and central Utah, whereas, surface waves’ incidence angles do appear to be important there.

scholarly journals Relatively small earthquakes of Javakheti Highland as the precursors of large earthquakes occuring in the Caucasus

2003 ◽  
Vol 3 (3/4) ◽  
pp. 165-170 ◽  
Author(s):  
M. Kachakhidze ◽  
N. Kachakhidze ◽  
R. Kiladze ◽  
V. Kukhianidze ◽  
G. Ramishvili
Keyword(s):  
Seismic Activity ◽  
Small Area ◽  
Active Regions ◽  
Large Earthquake ◽  
The Caucasus ◽  
Anomalous Change ◽  
Caucasus Region ◽  
Geophysical Processes ◽  
Large Earthquakes

Abstract. Javakheti Highland is one of the most seismic active regions of the Caucasus. The majority of earthquakes observed throughout the region occur within this small area (f = 40.8° – 41.8° ; l = 43.3° – 44.3°). One can expect that exclusive seismic activity of Javakheti Highland testifies to global geophysical processes which take place throughout the Caucasus region. Based on the above-mentioned, of interest was to study variation with time of the number of earthquakes occurring in Javakheti region. We analysed some 695 relatively small earthquakes (2.5 < M < 6.0) observed in Javalkheti Highland within the period of 1961–1992 with regard to large earthquakes M > 6.0 of the region which occurred in the same period. It was found that each large earthquake of the Caucasus is anticipated by clear precursor in a form of an anomalous change in the number of relatively small earthquakes in Javakheti Highland.

scholarly journals Seismically active area monitoring by robust TIR satellite techniques: a sensitivity analysis on low magnitude earthquakes in Greece and Turkey

2005 ◽  
Vol 5 (1) ◽  
pp. 101-108 ◽  
Author(s):  
R. Corrado ◽  
R. Caputo ◽  
C. Filizzola ◽  
N. Pergola ◽  
C. Pietrapertosa ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Active Regions ◽  
Space Time ◽  
Data Sets ◽  
Earthquake Occurrence ◽  
Validation Data ◽  
Analysis Technique ◽  
Definition Of ◽  
Area Monitoring ◽  
Low Magnitude

Abstract. Space-time TIR anomalies, observed from months to weeks before earthquake occurrence, have been suggested by several authors as pre-seismic signals. Up to now, such a claimed connection of TIR emission with seismic activity has been considered with some caution by scientific community mainly for the insufficiency of the validation data-sets and the scarce importance attached by those authors to other causes (e.g. meteorological) that, rather than seismic activity, could be responsible for the observed TIR signal fluctuations. A robust satellite data analysis technique (RAT) has been recently proposed which, thanks to a well-founded definition of TIR anomaly, seems to be able to identify anomalous space-time TIR signal transients even in very variable observational (satellite view angle, land topography and coverage, etc.) and natural (e.g. meteorological) conditions. Its possible application to satellite TIR surveys in seismically active regions has been already tested in the case of several earthquakes (Irpinia: 23 November 1980, Athens: 7 September 1999, Izmit: 17 August 1999) of magnitude higher than 5.5 by using a validation/confutation approach, devoted to verify the presence/absence of anomalous space-time TIR transients in the presence/absence of seismic activity. In these cases, a magnitude threshold (generally M<5) was arbitrarily chosen in order to identify seismically unperturbed periods for confutation purposes. In this work, 9 medium-low magnitude (4<Mb<5.5) earthquakes which occurred in Greece and Turkey have been analyzed in order to verify if, even in these cases, anomalous TIR transients can be observed. The analysis, which was performed using 8 years of Meteosat TIR observations, demonstrated that anomalous TIR transients can be observed even in the presence of medium-low magnitude earthquakes (4<Mb<5.5). As far as the research (just started) of possible correlation among TIR anomalies and earthquake occurrence is concerned, such a result suggests that: a) in order to identify seismically unperturbed periods for confutation purposes, a magnitude threshold (at least) lower than 4 should be used; b) the proposed validation/confutation approach should be applied in low-seismicity areas in order to find suitably long seismically quiescent periods.

scholarly journals Some possible correlations between electro-magnetic emission and seismic activity during West Bohemia 2008 earthquake swarm

Solid Earth ◽  
2010 ◽  
Vol 1 (1) ◽  
pp. 93-98 ◽  
Author(s):  
P. Kolář
Keyword(s):  
Seismic Activity ◽  
Earthquake Swarm ◽  
Electromagnetic Emission ◽  
Active Regions ◽  
Observation Time ◽  
Time Interval ◽  
Seismic Region ◽  
West Bohemia ◽  
Long Time ◽  
Electro Magnetic

Abstract. A potential link between electromagnetic emission (EME) and seismic activity (SA) has been the subject of scientific speculations for a long time. EME versus SA relations obtained during the 2008 earthquake swarm which occurred in West Bohemia are presented. First, a brief characterisation of the seismic region and then the EME recording method and data analysis will be described. No simple direct link between EME and SA intensity was observed, nevertheless a deeper statistical analysis indicates: (i) slight increase of EME activity in the time interval 60 to 30 min before a seismic event with prevalent periods about 10 min, (ii) some gap in EME activity approximately 2 h after the event, and (iii) again a flat maximum about 4 h after the seismic events. These results qualitatively correspond with the observations from other seismically active regions (Fraser-Smith et al., 1990). The global decrease of EME activity correlating with the swarm activity decay was also observed. Due to the incomplete EME data and short observation time, these results are limited in reliability and are indicative only.

scholarly journals Need for Speed: An Efficient Algorithm for Calculation of Single-Parameter Expected Value of Partial Perfect Information

2013 ◽  
Vol 16 (2) ◽  
pp. 438-448 ◽  
Author(s):  
Mohsen Sadatsafavi ◽  
Nick Bansback ◽  
Zafar Zafari ◽  
Mehdi Najafzadeh ◽  
Carlo Marra
Keyword(s):  
Efficient Algorithm ◽  
Expected Value ◽  
Perfect Information ◽  
Single Parameter

scholarly journals Radon and tectonic activity of the faults at the Central Mongolia

2019 ◽  
Vol 487 (5) ◽  
pp. 538-542
Author(s):  
K. Z. Seminsky ◽  
A. A. Bobrov ◽  
S. Demberel
Keyword(s):  
Seismic Hazard ◽  
Seismic Activity ◽  
Active Regions ◽  
Tectonic Activity ◽  
Fault Activity ◽  
Stages Of Development ◽  
Central Mongolia ◽  
Dynamic Framework ◽  
The Relationship ◽  
Late Stages

The relationship between the radon and tectonic activity of the faults for two geodynamically active regions of Central Mongolia is shown. Radon fault activity grew with increased seismic activity and with an increase in the contribution of extension in the dynamic framework of their formation. It is higher in concentrated faults of late stages of development compared with wide zones of fractures in the early stages of the formation. The established patterns will help increase the effectiveness of the use of radon surveys in studies of the seismic hazard of faults of the Earth’s crust.

scholarly journals SEISMICITY of the CARPATHIANS in 2015

2021 ◽  
pp. 31-42
Author(s):  
S. Verbitsky ◽  
R. Pronishin ◽  
V. Prokopishin ◽  
A. Stets’kiv ◽  
M. Chuba ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Seismic Energy ◽  
Earthquake Source ◽  
Epicentral Area ◽  
The Carpathians ◽  
Carpathian Region ◽  
Vrancea Zone ◽  
Maximum Earthquake ◽  
Academy Of Sciences ◽  
Catalogue Of Earthquakes

The article describes seismic observations in the Carpathian region in 2015, which were carried out, as before, by two organizations from two states: in Ukraine – the Seismicity department of the Carpathian region of the Institute of Geophysics of the NAS of Ukraine, in Moldova – the Seismology laboratory of the Institute of Geology and Seismology of the Academy of Sciences of Moldova. 20 stationary digital stations with a processing center in L'viv and six stations with a center in Chisinau operated in Ukraine and Moldova respectively. Different programs, local hodographs and magnitudes were used. The consolidated catalogue of earthquakes was created in L'viv. The total number of earthquakes in 2015 was NΣ=164 in the ranges: KR=4.7–12.2, h=1–160 km. The total seismic energy ΣE=5.381012 J. 23 earthquakes with depths h=50–160 km were located in the Vrancea zone. The maximum earthquake with KR=12.2 was registered on January 24 in the Vrancha mountains with hрР=89 km. In the Precarpathian region, nine events with energy classes KR=4.7–8.9 were registered, the total seismic energy of which is ΣЕ=1.25109 J. Increased seismic activity was observed in Transcarpathia. A series of tangible earthquakes with aftershocks was recorded in the Tyachiv area. Their total number was NΣ=77. The strongest tangible earthquake occurred in the area of Okrugla village on July 19 with KR=11.1. The earthquake source is located in the Earth's crust at a depth of h=7.7 km. The earthquake was felt by the population in the epicentral area with an intensity of I=6. In addition, this earthquake, like 5 others, was felt in the territory of northern Romania. In general, a decrease in the seismicity level in the Carpathians in 2015 was observed compared to that in 2013 and 2014.

scholarly journals Electromagnetic signals of crust creep motion

2011 ◽  
Vol 3 (1) ◽  
pp. 335-354
Author(s):  
V. N. Uvarov ◽  
G. I. Drushin ◽  
D. V. Sannikov
Keyword(s):  
Field Experiment ◽  
Electromagnetic Radiation ◽  
Seismic Activity ◽  
Active Regions ◽  
Short Description ◽  
Technical Noise ◽  
Probable Source ◽  
Electromagnetic Signals

Abstract. A method of registration and allocation of the nearest located sources of natural electromagnetic radiation is developed. Most likely, these sourses in seismically active regions originate from lithisperes. A short description of this method is given. We have carried out a field experiment in the region with small levels of technical noise and high levels of micro-seismic activity (Kamchatka, r. Karimschyna). A number of fragments of the received data are analysed. A large variety of registered signals are shown. It is shown that the most probable source of these signals has lithospheres origin.

scholarly journals Moderate seismic activity affects contemporary sediment yields

2014 ◽  
Vol 38 (2) ◽  
pp. 145-172 ◽  
Author(s):  
Matthias Vanmaercke ◽  
Albert J. Kettner ◽  
Miet Van Den Eeckhaut ◽  
Jean Poesen ◽  
Anna Mamaliga ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Human Impacts ◽  
Active Regions ◽  
Large River ◽  
Exceedance Probability ◽  
Data Sets ◽  
Ground Acceleration ◽  
Regional Patterns ◽  
Sediment Yields ◽  
Cross Correlations

Current models aiming to simulate contemporary sediment yield (SY) implicitly assume that tectonic effects are either irrelevant or are reflected by catchment topography. In this study we analyse the relation between SY and seismic activity, a component of tectonic processes. Results show a spatial correlation between SY and seismic activity expressed as the estimated peak ground acceleration (PGA) with a 10% exceedance probability in 50 years. PGA has a significant impact on the spatial variation of SY, even after correcting for cross-correlations with topography, lithology or other factors that may influence SY. Based on three distinct data sets, we demonstrate that this effect is significant both for small catchments in Europe (0.3–3940 km2) and for large river systems worldwide (1580–6.15×106 km2) and that seismic activity may be even more important for explaining regional variation in SY than land use or many other commonly considered factors (e.g. catchment area, climate). We show that explicitly considering seismic activity may lead to SY-estimates that easily deviate a factor 2 or more compared to estimates that do not consider seismic activity. This is not only the case for highly seismically active regions: also in regions with a weak to moderate seismic regime seismic activity helps explaining regional patterns in SY. We argue that these findings have important implications for a better understanding of SY and its sensitivity to human impacts, as well as for our comprehension of sediment fluxes at longer timescales.

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