The 2011 West Bohemia (Central Europe) earthquake swarm compared with the previous swarms of 2000 and 2008

2015 ◽  
Vol 19 (4) ◽  
pp. 899-913 ◽  
Author(s):  
Hana Čermáková ◽  
Josef Horálek
Keyword(s):  
Central Europe ◽  
Earthquake Swarm ◽  
West Bohemia

scholarly journals Crustal deformations in the epicentral area of the West Bohemia 2008 earthquake swarm in central Europe

2012 ◽  
Vol 117 (B7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Vladimír Schenk ◽  
Zdeňka Schenková ◽  
Zuzana Jechumtálová ◽  
Richard Pichl
Keyword(s):  
Central Europe ◽  
Earthquake Swarm ◽  
The West ◽  
Epicentral Area ◽  
West Bohemia

Focal Mechanisms of West Bohemia, Central Europe, Earthquakes—End of May 2014: Evidence of Volume Changes

2021 ◽  
Author(s):  
Dana Křížová ◽  
Jiří Málek
Keyword(s):  
Central Europe ◽  
Moment Tensor ◽  
Waveform Inversion ◽  
Low Frequency ◽  
Earthquake Swarms ◽  
Quaternary Volcanism ◽  
Moment Tensors ◽  
Isotropic Part ◽  
West Bohemia ◽  
Source Mechanisms

Abstract West Bohemia is a region with a lot of mineral springs and gas outflows, which seems to be related to the remains of Quaternary volcanism in Central Europe. Earthquake swarms in shallow depths (less than 15 km) are very frequent there. We focused on the strongest earthquake over the past 30 yr (31 May, 2014 Mw∼3.8) and on two smaller ones (Mw∼2.9 and 2.5) from the same day. Seismograms from local and regional seismic stations were used to calculate the full and deviatoric moment tensors using low-frequency full-waveform inversion. The studied events have similar source mechanisms. The aforementioned earthquake sequence was selected to observe the isotropic part (negative value = implosion) of full moment tensors. It could relate to the motion and phase transition of fluids, especially water, and CO2. The main goal of this study is to contribute to clarification of the nature of earthquake swarms in the western edge of the Bohemian Massif. Negative value of the isotropic part of full moment tensor could be related to the closing of cracks and fissures during a rupture process.

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.

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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