TheoreticalPKIKP magnitude determination     

J. Janský  M. Kvasnička 《Studia Geophysica et Geodaetica》1992,36(1):20-25

Summary The estimation of the theoretical magnitude for deep foci based on the vertica component of medium-period PKIKP waves, Earth model PREM and source spectra is presented. The given graphs are valid for period T ranging from 1·6 s to 10 s, source depth of 25 km to 600 km and distance range of 16 500 km to 19 800 km. A simplified method of representing calibration curves is used.  相似文献   

A combined study of macroseismic data and focal mechanisms applied to the West-Bohemian earthquake,Czechoslovakia     

J. Zahradník  M. Antonini  G. Grünthal  J. Janský  D. Procházková  E. Schmedes  A. Špičak  J. Zedník 《Pure and Applied Geophysics》1990,133(1):53-71

The main shock of the West-Bohemian earthquake swarm, Czechoslovakia, (magnitudem=4.5, depthh=10 km) exhibits an irregular areal distribution of macroseismic intensities 6° to 7° MSK-64. Four lobes of the 6° isoseismal are found and the maximum observed intensity is located at a distance of 8 km from the instrumentally determined epicentre. This distribution can be explained by the energy flux of the directS wave generated by a circular source, the hypocentral location and focal mechanism of which are taken from independent instrumental studies. The theoretical intensity, which is assumed to be logarithmically proportional to the integrated squared ground-motion velocity (i.e.,I=const+log v ² (t)dt), fits the observed intensity with an overall root-mean-square error less than 0.5°. It is important that the present intensity data can also be equally well explained by the isotropic source. The fit was attained by means of a horizontally layered model though large fault zones and an extended sedimentary basin suggest a significant lateral heterogeneity of the epicentral region. The results encourage a broader application of the simple modelling technique used.  相似文献   

Consequences of transducer inductance for seismograph calibration     

Pekka Teikari  Vladimír Tobyáš  Reviewer J. Janský 《Studia Geophysica et Geodaetica》1986,30(3):257-267

Summary The magnification achieved with the standard sine-wave method using seismometers with the calibration and signal coils tightly wound on the same coil former can be erroneous at high frequencies due to the mutual inductance between both coils. An attempt was made to eliminate this influence from the calibration data. The application of theoretical equations was tested with a short-period digital seismograph.

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Deep structure of the lithosphere beneath the territory of Bulgaria     

Vladislav Babuška  Jaroslava Plomerová  Edelvays Spasov  Reviewer J. Janský 《Studia Geophysica et Geodaetica》1987,31(3):266-283

Summary Teleseismic P residuals calculated for waves arriving from various azimuths and angles of incidence, and a 3-D inversion of the residuals provided the basis for characterizing the uppermost mantle structure beneath Bulgaria. The Moesian Platform and the Rhodopean Massif are two different blocks characterized by a lithosphere thickness of about 130–140 km with a zone of lithosphere thinning along their contact. Both units have opposite patterns of the directional dependence of relatively high and low P velocities. This directional dependence is interpreted by dipping anisotropic structures in the subcrustal lithosphere, which probably represent remnants of paleosubductions of an old oceanic lithosphere.

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Refracted wave in a horizontally stratified medium with constant velocity gradients     

Jaromír Janský 《Studia Geophysica et Geodaetica》1969,13(4):423-443

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Isoseismals of the strongest Friuli aftershocks of September 1976     

Vít Kárník  Dana Procházková  Zdeňka Schenková  Julius Drimmel  Dieter Mayer-Rosa  Dragutin Cvijanovic  Vladimir Kuk  Andelka Miloševič  Francesco Giorgetti  Reviewer J. Janský 《Studia Geophysica et Geodaetica》1978,22(4):411-414

Summary Isoseismal maps of the three strongest Friuli aftershocks of September 1976 were compiled using the contributions from European countries within the shaken area. The characteristic features of the macroseismic fields are discussed.  相似文献   

Velocity-depth function ofP-waves in the region of the central bohemian massif     

Karel Holub  Reviewer J. Janský 《Studia Geophysica et Geodaetica》1974,18(4):390-393

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Analysis of the source scanning algorithm with a new P-wave picker     

J. Zahradník  J. Janský  V. Plicka 《Journal of Seismology》2015,19(2):423-441

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Interference amplitude curves of short period PKP waves     

J. Janský  M. Kvasnička 《Studia Geophysica et Geodaetica》1993,37(2):151-158

Summary Theoretical short-period amplitude-distance curves of PKP waves are calculated in the range of distances corresponding to the interference zone of the different branches of this waves. The combination of the zero-order approximation of the ray method and the Gaussian beam approach are used for the calculation. The calculated amplitudes are compared with the observed ones. A relatively good coincidence between the theoretical and observational curves has been found.  相似文献   

Correction of the level of magnification of the SVK vertical seismograph at the seismic station of průhonice (PRU)     

Vladimír Tobyáš  Reviewer J. Janský 《Studia Geophysica et Geodaetica》1981,25(1):99-103

Summary Drawing on the results of new measurements of the mechanical parameters of the SVK seismometer No. 5055, the level of magnification of the vertical seismograph used in the past, has been corrected. The amplitudes of the seismic waves from earthquakes in the period 1963–1978 have to be increased by 88% and the station correction for determining the magnitudes of earthquakes decreased by 0.274.  相似文献