Accuracy of the master-event and double-difference locations: synthetic tests and application to seismicity in West Bohemia, Czech Republic

2013 ◽  
Vol 17 (3) ◽  
pp. 841-859 ◽  
Author(s):  
Fateh Bouchaala ◽  
Václav Vavryčuk ◽  
Tomáš Fischer
Keyword(s):  
Czech Republic ◽  
Double Difference ◽  
West Bohemia ◽  
Master Event

scholarly journals A NEW ANGUIMORPH LIZARD FROM THE LOWER MIOCENE OF NORTH-WEST BOHEMIA, CZECH REPUBLIC

Palaeontology ◽  
2008 ◽  
Vol 51 (1) ◽  
pp. 81-94 ◽  
Author(s):  
JOZEF KLEMBARA
Keyword(s):  
Czech Republic ◽  
Lower Miocene ◽  
North West ◽  
West Bohemia

scholarly journals Velocity structure and the role of fluids in the West Bohemia Seismic Zone

2014 ◽  
Vol 6 (1) ◽  
pp. 511-534
Author(s):  
C. Alexandrakis ◽  
M. Calò ◽  
F. Bouchaala ◽  
V. Vavryčuk
Keyword(s):  
Velocity Structure ◽  
Weighted Average ◽  
Tectonic Stress ◽  
Double Difference ◽  
Seismic Zone ◽  
The West ◽  
Fluid Concentration ◽  
West Bohemia ◽  
Basic Characteristics ◽  
Tomography Method

Abstract. In this study, we apply the double-difference tomography method to investigate the detailed 3-D structure within and around the Nový Kostel seismic zone, an area in the Czech Republic known for frequent occurrences of earthquake swarms. We use data from the extensively analyzed 2008 swarm, which has known focal mechanisms, principal faults, tectonic stress, source migration and other basic characteristics. We selected about 500 microearthquakes recorded at 22 local seismic stations of the West Bohemia Network (WEBNET). Applying double-difference tomography, combined with Weighted Average Model post-processing to correct for parameter dependence effects, we produce and interpret 3-D models of the Vp-to-Vs ratio (Vp/Vs) in and around the focal zone. The modeled Vp-to-Vs ratio shows several distinct structures, namely an area of high Vp-to-Vs ratio correlating with the microearthquakes, and a layer of low values directly above it. These structures may reflect changes in lithology and/or fluid concentration. The overlaying low Vp-to-Vs ratio layer coincides with high density metamorphic unit associated with the Fichtelgebirge (Smrčiny) granitic intrusion. It is possible that the base of the layer acts as a fluid trap, resulting in the observed periodic swarms.

scholarly journals Germinative capacity and energy of critically endangered Ojców birch (Betula oycoviensis Besser) in the Czech Republic

2020 ◽  
Vol 66 (No. 6) ◽  
pp. 227-235
Author(s):  
Josef Gallo ◽  
Zdeněk Vacek ◽  
Martin Baláš ◽  
Stanislav Vacek
Keyword(s):  
Czech Republic ◽  
Critically Endangered ◽  
Important Indicator ◽  
The Czech Republic ◽  
Tree Defoliation ◽  
West Bohemia ◽  
Individual Trees

Ojców birch (Betula oycoviensis Besser) is a rare and critically endangered taxon of the genus Betula. Its distribution is limited to few countries in Europe. In the Czech Republic, this taxon, characterized by typical shrubby habitus, has been found in fewer than 70 tree individuals, prevailingly in the studied locality Volyně, West Bohemia. This study was focused on the germinative capacity and germinative energy of this taxon, as it is an important indicator of possible regeneration of the trees in nature and for conservation. Non-stratified seeds (2 200 pcs) and stratified ones (2 200 pcs) were compared to each other and in relation to dendrometric tree parameters. The results showed no significant (P > 0.1) differences between stratification variants in total germination (higher by 0.8% in stratified), though stratification improved germinative energy. Germination was in 1st week higher by 6.0% in stratified variant, respectively marginally (P < 0.1) higher in 2nd week in non-stratified variant. However, both germinative capacity and germinative energy were significantly (P < 0.01) variable between individual trees. The germinative capacity was significantly (P < 0.05) positively correlated with tree defoliation. Tiny seeds and triploid trees exhibited very low and zero germinative capacity and energy, respectively. Totally, seeds exhibited sufficient germinative capacity and germinative energy of 23.1% (0.0–62.5%). This suggests that the trees can be potentially used for this type of Ojców birch regeneration i.e. generatively from seeds, although rather in controlled artificial conditions.

DEVELOPMENT AND INNOVATION OF TECHNICAL EDUCATION IN CZECH REPUBLIC AND ITS IMPLEMENTATION AT THE UNIVERSITY OF WEST BOHEMIA

2016 ◽  
Author(s):  
Tomáš Keckstein ◽  
Petr Votápek ◽  
Jakub Jirásko ◽  
Šimon Pušman
Keyword(s):  
Czech Republic ◽  
Technical Education ◽  
West Bohemia ◽  
The University

scholarly journals Detection of Stress Anomaly Produced by Interaction of Compressive Fault Steps in the West Bohemia Swarm Region, Czech Republic

Tectonics ◽  
2018 ◽  
Vol 37 (11) ◽  
pp. 4212-4225 ◽  
Author(s):  
Václav Vavryčuk ◽  
Petra Adamová
Keyword(s):  
Czech Republic ◽  
The West ◽  
West Bohemia ◽  
Detection Of Stress

scholarly journals New records of Pennsylvanian trigonotarbid arachnids from West Bohemia, Czech Republic

2013 ◽  
Vol 41 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Ivana Hradská ◽  
Jason A. Dunlop
Keyword(s):  
Czech Republic ◽  
New Records ◽  
West Bohemia

The prevalence of tick-borne encephalitis in the region of West Bohemia (Czech Republic) between 1960–2005

2008 ◽  
Vol 158 (3-4) ◽  
pp. 91-97 ◽  
Author(s):  
Petr Pazdiora ◽  
Jindřiška Benešová ◽  
Zdenka Böhmová ◽  
Jitka Králíková ◽  
Anna Kubátová ◽  
...  
Keyword(s):  
Czech Republic ◽  
Tick Borne Encephalitis ◽  
West Bohemia

From earthquake swarm to a main shock–aftershocks: the 2018 activity in West Bohemia/Vogtland

2020 ◽  
Vol 224 (3) ◽  
pp. 1835-1848
Author(s):  
M Bachura ◽  
T Fischer ◽  
J Doubravová ◽  
J Horálek
Keyword(s):  
Main Shock ◽  
Fault Plane ◽  
Earthquake Swarm ◽  
Seismic Energy ◽  
Aftershock Sequence ◽  
Double Difference ◽  
Differential Stress ◽  
West Bohemia ◽  
Spatio Temporal ◽  
Insight Into

SUMMARY In earthquake swarms, seismic energy is released gradually by many earthquakes without a dominant event, which offers detailed insight into the processes on activated faults. The swarm of May 2018 that occurred in West Bohemia/Vogtland region included more than 4000 earthquakes with ML =〈0.5, 3.8&x3009 x232A;and its character showed significant changes during the two weeks duration: what started as a pure earthquake swarm ended as a typical main shock–aftershock sequence. Based on precise double-difference relocations, four fault segments differing in strikes and dips were identified with similar dimensions. First, two segments of typical earthquake swarm character took place, and at the end a fault segment hosting a main shock–aftershock sequence was activated. The differences were observable in the earthquakes spatio-temporal evolutions (systematic versus disordered migration of the hypocentres), b-values (>1.3 for the swarm, <1 for the main shock–aftershocks), or the smoothness of seismic moment spatial distribution along the fault plane. Our findings can be interpreted by local variations of fault rheology, differential stress and/or smoothness of the faults surface, possibly related to the crustal fluids circulating along the fault plane and their interplay with the seismic cycle.

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