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2. Finite seismic source parameters in ferred from stopping phases for selected events of West Bohemia 2000 swarm
- Creator:
- Kolář, Petr and Růžek, Bohuslav
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, zemětřesení, earthquake, Čechy západní (Česko), Bohemia, Western (Czechia), finite seismic source, West Bohemia earthquake swarm, stopping phases, 7, and 551
- Language:
- English
- Description:
- Parameters of finite seismic source model were determined for a set of 36 selected events of the West Bohemia 2000 earthquakes swarm (Ml from 1.7 to 3.0) using stopping phases method. Two stopping phases are generated along the source border where the rupture process terminates and these phases form Hilbert transform pair, which is also the criterion for their identification. Circular and e liptical source models were considered and corresponding source parameters were calculated by inverting interpreted stopping phases delays. As generalization of circular to elliptical model was found to be statistically insignificant, only results related to the circular source including error estimates are presented. Our results are in a good agreement with previously published theoretical formula concerning source radius and magnitude and also fairly well confirm general theoretical assumption about constant stress drop. The determined stress drop ranges between 1 - 10 MPa with the typical value of 2.4 MPa., Petr Kolář and Bohuslav Růžek., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Groundwater level variations in the seismically active region of Western Bohemia in the years 2005-2010
- Creator:
- Gaždová, Renata, Oldřich Novotný, Málek, Jiří, Valenta, Jan, Brož, Milan, and Kolínský, Petr
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, zemětřesení, seizmicita, earthquake, seismicity, Čechy západní (Česko), Bohemia, Western (Czechia), earthquake swarm, groundwater level, 7, and 551
- Language:
- English
- Description:
- The western part of the Bohemian Massif (Vogtland/West-Bohemia region at the Czech-German border) is characterized by relatively frequent intraplate earthquake swarms and by other manifestations of current geodynamic activity, such as mofettes, mineral and thermal springs. In this study we analyze variations of groundwater level in four hydrological wells in the region during the years 2005-2010. Monitoring during the previous time interval of 2000-2004 is also mentioned and used for comparison. Two of the wells are located in the epicentral region of Nový Kostel, and the other wells are more distant. The time interval includes the 2008 earthquake swarm when all the wells displayed a noticeable drop in the water level. This effect was observed up to epicentral distances of nearly 30 km, which exceeds the distances of hydrological changes observed during previous earthquake swarms. Moreover, it seems that a small rise in the water level preceded the intervals of increased seismic activity, which could represent a certain precursory phenomenon. On the other hand, the hydrological changes in the Nový Kostel area were relatively small, indicating that this epicentral area is not hydrologically linked with the seismically active fault at depth. Consequently, more suitable localities for hydrological monitoring should be sought in a broader vicinity of Nový Kostel., Renata Gaždová, Oldřich Novotný, Jiří Málek, Jan Valenta, Milan Brož and Petr Kolínský., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Horizontal strain 3He/4He ratio and intra-plate earthquake swarms
- Creator:
- Vladimír Schenk and Zdeňka Schenková
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, zemětřesení, earthquake, Čechy západní (Česko), Bohemia, Western (Czechia), horizontal strain, 3He/4He ratio, intra-plate earthquake swarms, 7, and 551
- Language:
- English
- Description:
- In the West Bohemian region, Central Europe, the volcanic activity appeared in late Tertiary, the Miocene. The present intraplate magmatic activity makes itself felt by flows of gaseous and liquid fluids, enhanced geodynamic mobility of geological structures and generation of earthquake swarms. Position data of two permanent Global Navigation Satellite Systems (GNSS) stations located in the region were used to calculate the time variations of the horizontal strain field that were compared with the 3He/4He ratios and earthquake swarm occurrences. The strains and 3He/4He ratios displayed a positive relation supported by the earlier opinions on the dependence of the dynamics of the region on the fluid occurrence. Analysis of these quantities observed in 2006-2007 period indicated when the compressions calmed and the 3He/4He ratios grew then the earthquake events occurred. It presumes the detected variations relate to compressions and extensions in the region. The strain field changes monitored during the 2008 swarm proved the relation found above. The observed connections could be applied in future at selected regions in earthquake forecast procedures., Vladimír Schenk and Zdenka Schenková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5. Josef Hložek, Hrady západních a jižních Čech ve světle nedestruktivních archeologických průzkumů Katedry archeologie Západočeské univerzity v Plzni
- Creator:
- Filip Velímský
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- archeologické výzkumy, hradní architektura, kastelologie, excavations (archaeology), castle architecture, castellology, Čechy západní (Česko), Čechy jižní (Česko), Bohemia, Western (Czechia), Bohemia, Southern (Czechia), 8, and 902
- Language:
- Czech
- Description:
- Filip Velímský.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. Pavel Vařeka, Petr Rožmberský a kol., Středověká krajina na střední Úslavě I
- Creator:
- Tomáš Klír
- Format:
- Type:
- model:article and TEXT
- Subject:
- archeologické výzkumy, archeologie středověku, sídelní archeologie, krajinná archeologie, excavations (archaeology), medieval archaeology, settlement archaeology, landscape archaeology, Čechy západní (Česko), Úslava (Česko : řeka), Bohemia, Western (Czechia), Úslava River (Czechia), 8, and 902
- Language:
- Czech
- Description:
- [autor recenze] Tomáš Klír.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
7. Seismic activity in West Bohemia from 2001 - 2006
- Creator:
- Nehybka, Vladimír and Tilšarová, Radka
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, seizmologie, zemětřesení, seismology, earthquake, Čechy západní (Česko), Vogtland (Německo), Nový Kostel (Česko), Vogtland (Germany), Bohemia, Western (Czechia), Nový Kostel (Czechia), earthquake swarm, microearthquake, en echelon, tectonic line, 7, and 551
- Language:
- English
- Description:
- This article is concerned with seismicity in the region of West Bohemia - Vogtland after the Nový Kostel swarm of 2000. Seismicity during the period 2001 - 2006 is weak, though with several clusters of earthquakes; although these do not meet the criteria for a seismic swarm, their groupi ng in time and spacing along a line give an impression of tectonic disturbances and their behaviour in a period between swarms., Vladimír Nehybka and Radka Tilšarová., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8. The Western Bohemia uppermost crust rayleigh wave tomography
- Creator:
- Kolínský, Petr and Johana Brokešová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, geofyzika, geophysics, Čechy západní (Česko), Bohemia, Western (Czechia), group velocity, frequency-time analysis, multiple filtering, Rayleigh wave tomography, 7, and 551
- Language:
- English
- Description:
- We apply a traditional method of surface wave tomography as a new approach to investigate the uppermost crust velocities in the Western Bohemia region (Czech Republic). It enables us to look for velocity distribution in a small scale of tens of kilometers. We measure Rayleigh wave group velocity dispersion curves in a period range 0.25 - 2.0 s along paths crossing the region of interest. We use modified multiple-filtering method for frequency-time analysis. We compute 2-D tomography maps of group velocity distribution in the region for eight selected periods using the standard methods and programs described in literature. We discuss the velocity distribution with respect to results of former study by Nehybka and Skácelová (1997). We present a set of local dispersion curves which may be further inverted to obtain a 3-D shear wave velocity image of the area., Petr Kolínský and Johana Brokešová., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. To crustal deformation modeling of the West Bohemia swarm area, Central Europe
- Creator:
- Vladimír Schenk and Zdeňka Schenková
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, družicová geodezie, satellite geodesy, Čechy západní (Česko), Bohemia, Western (Czechia), crustal deformation, seismic cycle, 7, and 551
- Language:
- English
- Description:
- In this article we solve the non-standard situation that arose after publishing our paper "Crustal deformations in the epicentral area of the West Bohemia 2008 earthquake swarm in central Europe" (Schenk et al., 2012). Horálek and Fischer wrote a statement regarding our publication, sent it to specialists interested in research in the West Bohemia swarm area, and questioned the reliability of the seismic data used in our work. Since the statement regarding the reliability of our work was not directly sent to us we are using this journal to return to professional discussion regarding our results. In this paper we review scientific arguments made in their statement and provide review of various studies on West Bohemia tectonics and related seismicity., Vladimír Schenk and Zdeňka Schenková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
10. Visualization of the fault slip connected with the West Bohemia earthquake swarms
- Creator:
- Kolář, Petr, Růžek, Bohuslav, Boušková, Alena, and Horálek, Josef
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, zemětřesení, earthquake, Čechy západní (Česko), asperity, West Bohemia earthquake swarm, fault slip, fault dynamics, 7, and 551
- Language:
- English
- Description:
- The West Bohemia earthquake swarm foci are approximated by a circular seismic source model, which radius is assumed to depend only on magnitude of the event. We consider two different models of average slip (i) a constant slip and (ii) a slip exponentially scaled to the magnitude of the event. Based on these assumptions, we stacked the contributions of individual events into representative final fault slip. We processed in such a way four significant swarms recorded during the last three decades in 1986, 1997, 2000 and 2008. Constant slip model indicates final slip was composed of 2 or 3 principal asperities located on one or two different planes. On the contrary, scaled slip model indicates that one big asperity prevails. It is not possible yet to select the preferred slip model. Analysis of the temporal activity of all swarms generally shows three principal phases: starting phase, main phase and fading phase; the upwards trend of activity spreading was observed (slip animation is presented in www supplement http://www.ig.cas.cz/kolar/StopPhase/Asperity). The maximal possible cumulative slip value may have reached the order of meters., Petr Kolář, Bohuslav Růžek, Alena Boušková and Josef Horálek., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public