Rayleigh waves in the period range 0.2 - 3.0 s from eight quarry blasts are analyzed to obtain S-wave velocity model beneath the Příbram seven-station array in the Czech Republic. Locations and origin times of blasts are estimated using P- and S-wave onsets and then verified at the quarry in the vicinity of the location. This blind test confirms a sufficient precision of the location procedure for identification of quarries. Epicentral distances are in the range from 16 to 52 km. Group velocity dispersion curves of Rayleigh waves are determined by the frequency-time analysis. An average group velocity beneath the array for each period is computed with the help of mean travel-time curve for all blasts and stations. The resultant group velocity dispersion curve is inverted to obtain a 1-D S-wave velocity model using the Isometric method. The results are compared with known geological structure in the area of interest., Renata Gaždová, Petr Kolínský, Jiří Málek and Jan Vilhelm., 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