Publication Date:
2014-09-18
Description:
Schenk et al. [2012] present a crustal deformation model of the earthquake swarm area in West Bohemia (Czech-German border area, Central Europe), which consists of rotating crustal blocks. The model is based on GPS measurements showing a surface vertical displacement of 167 mm followed by a rebound of 55 mm at one GPS point due to a local earthquake swarm, MLmax ≈ 3.8, in 2008. However, such vertical crustal-block movements are extremely large for the geodynamic-activity scale in Central Europe. A numerical model, which the authors carried out using the Coulomb 3.2 software, is rather vague: data and methods are poorly stated, assumed block-motion rates of about 1 mm per day and horizontal extension of 64 mm in the epicental area are beyond the bounds of reality. Further Schenk et al. (2012) analyzed the spatial distribution of the 2008-swarm foci, unfortunately they used erroneous location data. On the basis of the incorrect locations they justified their idea of rotating blocks. In this contribution we present the GPS data from another local network, from permanent station located in the epicentral area and data from precise leveling, and demonstrate that the GPS data used by Schenk et al. (2012) are questionable. We also point out a spurious pattern of the spatial distribution of the 2008-swam due to improper location-data used and give a correct pattern of focal distribution. Finally we conclude that the quality and treatment of both GPS and seismic data makes the whole study purely speculative.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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