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
A grant project for the period 2003-2005, supported by the Grant Agency of the Czech Republic, was set up to determine properties of seismic waves and the structure of the uppermost part of the Earth´s crust in the territory of northern Moravia and Silesia. Quarry blasts and mining induced seismic events served as seismic sources. Permanent, temporary and portable seismic stations were used for the monitoring of these seismic events. During the experiments local microearthquakes were also detected and localized. For the complex evaluation of seismic wave features, data of the CELEBRATION 2000 and SUDETES 2003 refraction experiments were incorporated, as well. The velocity-depth dependence of body waves was searched by joint inversions of travel times of Pg/Sg phases. A special feature of the wave trains, generated by quarry blasts, was a pronounced dispersive character of short-period Rayleigh surface waves. These waves enabled us to establish their dispersion curves, on the basis of which the structure of superficial layers was determined down to a depth of several hundreds of meters., Karel Holub, Jaromír Knejzlík, Bohuslav Růžek, Jana Rušajová and Oldřich Novotný., and Obsahuje bibliografii