TY  - JOUR
A1  - Hiemer, Stefan
A1  - Rößler, Dirk
A1  - Scherbaum, Frank
T1  - Monitoring the West Bohemian earthquake swarm in 2008/2009 by a temporary small-aperture seismic array
JF  - Journal of seismology
N2  - The most recent intense earthquake swarm in West Bohemia lasted from 6 October 2008 to January 2009. Starting 12 days after the onset, the University of Potsdam monitored the swarm by a temporary small-aperture seismic array at 10 km epicentral distance. The purpose of the installation was a complete monitoring of the swarm including micro-earthquakes (M (L) < 0). We identify earthquakes using a conventional short-term average/long-term average trigger combined with sliding-window frequency-wavenumber and polarisation analyses. The resulting earthquake catalogue consists of 14,530 earthquakes between 19 October 2008 and 18 March 2009 with magnitudes in the range of -aEuro parts per thousand 1.2 a parts per thousand currency signaEuro parts per thousand M (L) a parts per thousand currency signaEuro parts per thousand 2.7. The small-aperture seismic array substantially lowers the detection threshold to about M (c) = -aEuro parts per thousand 0.4, when compared to the regional networks operating in West Bohemia (M (c) > 0.0). In the course of this work, the main temporal features (frequency-magnitude distribution, propagation of back azimuth and horizontal slowness, occurrence rate of aftershock sequences and interevent-time distribution) of the recent 2008/2009 earthquake swarm are presented and discussed. Temporal changes of the coefficient of variation (based on interevent times) suggest that the swarm earthquake activity of the 2008/2009 swarm terminates by 12 January 2009. During the main phase in our studied swarm period after 19 October, the b value of the Gutenberg-Richter relation decreases from 1.2 to 0.8. This trend is also reflected in the power-law behavior of the seismic moment release. The corresponding total seismic moment release of 1.02x10(17) Nm is equivalent to M (L,max) = 5.4.
KW  - Swarm earthquakes
KW  - West Bohemia
KW  - Array seismology
KW  - Frequency-magnitude distribution
Y1  - 2012
U6  - https://doi.org/10.1007/s10950-011-9256-5
SN  - 1383-4649
VL  - 16
IS  - 2
SP  - 169
EP  - 182
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Munoz, Gerard
A1  - Weckmann, Ute
A1  - Pek, Josef
A1  - Kovacikova, Svetlana
A1  - Klanica, Radek
T1  - Regional two-dimensional magnetotelluric profile in West Bohemia/Vogtland reveals deep conductive channel into the earthquake swarm region
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - The West Bohemia/Vogtland region, characterized by the intersection of the Eger (Ohre) Rift and the Marianske Lazne fault, is a geodynamically active area exhibiting repeated occurrence of earthquake swarms, massive CO2 emanations and mid Pleistocene volcanism. The Eger Rift is the only known intra-continental region in Europe where such deep seated, active lithospheric processes currently take place. We present an image of electrical resistivity obtained from two-dimensional inversion of magnetotelluric (MT) data acquired along a regional profile crossing the Eger Rift. At the near surface, the Cheb basin and the aquifer feeding the mofette fields of Bublak and Hartousov have been imaged as part of a region of very low resistivity. The most striking resistivity feature, however, is a deep reaching conductive channel which extends from the surface into the lower crust spatially correlated with the hypocentres of the seismic events of the Novy Kostel Focal Zone. This channel has been interpreted as imaging a pathway from a possible mid-crustal fluid reservoir to the surface. The resistivity model reinforces the relation between the fluid circulation along deep-reaching faults and the generation of the earthquakes. Additionally, a further conductive channel has been revealed to the south of the profile. This other feature could be associated to fossil hydrothermal alteration related to Mytina and/or Neualbenreuth Maar structures or alternatively could be the signature of a structure associated to the suture between the Saxo-Thuringian and Tepla-Barrandian zones, whose surface expression is located only a few kilometres away.
KW  - Magnetotellurics
KW  - West Bohemia
KW  - Vogtland
KW  - Earthquake swarm
KW  - Conductive channel
KW  - Fluids
Y1  - 2018
U6  - https://doi.org/10.1016/j.tecto.2018.01.012
SN  - 0040-1951
SN  - 1879-3266
VL  - 727
SP  - 1
EP  - 11
PB  - Elsevier
CY  - Amsterdam
ER  -