Relation between microseisms recorded at seismic stations Praha and Průhonice     

Dana Procházková  Reviewer A. Zátopek 《Studia Geophysica et Geodaetica》1978,22(4):362-367

Summary In order to compare the course of microseisms recorded at the seismic stations of Praha and Prhonice, the relation between Praha (Wiechert astatic inverted pendulum) and Prhonice (Kirnos — electromagnetic seismographs) amplitudes was derived, using data from the time interval September 1967 — June 1968. It was found that the amplitudes at both stations are almost parallel in time with three almost simultaneous local maxima. In addition corresponding relations have also been found to be valid for the periods.  相似文献   

Twenty five years of the Geophysical Institute of the Czechoslovak Academy of Sciences     

Václav Bucha 《Studia Geophysica et Geodaetica》1978,22(2):208-212

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An algorithm for the minimum-length least-squares solution of a set of observation equations     

František Charamza  Reviewer L. Kubáček 《Studia Geophysica et Geodaetica》1978,22(2):129-139

Summary A new computer-oriented algorithm GSO is presented for solving overdetermined systems of linear observation equations according to the principle of the least-squares method. The matrix of the system of observation equations may be of deficient rank. In this case the algorithm leads to the vector of unknowns with a minimum Euclidean norm. Alternatively, it is possible to minimize the norm of a subvector formed by a selected group of unknowns. The weight coefficient matrix, corresponding to the vector (subvector) of unknows, has the least possible trace. The algorithm GSO is based on the Gram-Schmidt Orthogonalization of suitably defined augmented matrices. The establishing and solving of normal equations is not necessary. Apart from the unknowns and residuals, GSO also determines the factorized weight coefficient matrices of the adjusted values.Presented at the I.A.G. International Symposium on Optimization of Design and Computation of Control Networks, Sopron, Hungary 1977.  相似文献   

On characteristic frequencies of a five-component model of magnetospheric plasma     

Jaroslava Bošková  Reviewer K. Dobeš 《Studia Geophysica et Geodaetica》1978,22(2):160-164

Summary The author gives more general relations derived for characteristic frequencies of a more complex plasma model. One may assume that expressions derived herein, represent a more appropriate approximation of reality, especially in regions of ionospheric and magnetospheric plasma with a higher concentration of heavy ions.  相似文献   

Magnitude scale structure from filtered broadbandP-wave records     

A. Roglinov  J. Horálek  A. Plešinger  J. Vaněk 《Pure and Applied Geophysics》1978,117(4):816-826

A series of Hokkaido events, recorded by the FBV Broadband Seismograph System at the KHC Seismic Station, is used to study the structure of the earthquake magnitude scale on the basis of maximum velocity amplitudesA _vmax of teleseismicPwaves in different period bands. Amplitude-periodband (APB) diagrams are constructed for each event. According to the shape of the APB diagrams the events investigated can be divided into three types: (a) events with largestA _vmax values in the intermediate period range (periods ofA _vmax from 2.2 to 23 sec), (b) events with largestA _vmax values in the short-period range (periods ofA _vmax from 1 to 2 sec), (c) events exhibiting anomalous APB diagrams. Type (a) events seem to represent the process of wave generation that prevails for shallow earthquakes. Type (b) events approach to explosive-like generation of seismic waves. The nature of the exceptionally occurring type (c) events must be clarified in further investigations. The influence of the type of earthquake on the magnitude values estimated on the basis of standard class A and B (short-period and intermediate-band) seismograms is demonstrated. It appears that for estimating correct values of earthquake magnitudes complementary information on the process of seismic wave generation in the focus is necessary. At teleseismic distances this information can be obtained from either APB diagrams or amplitude spectra ofP waves recorded, e.g., by broadband velocity sensing instruments.  相似文献   

Geodynamic interpretation of the earthquake distribution in the kermadec subduction zone     

Václav Hanuš  Jiří Vaněk  Reviewer A. Zátopek 《Studia Geophysica et Geodaetica》1978,22(3):259-275

Summary The morphology of the Wadati-Benioff zone in the Kermadec region, based on the distribution of 1100 earthquake foci, verified the existence of an intermediate aseismic gap and its relation to active andesitic volcanism, and the non-uniformity of subduction due to the hampering effect of the main structural features of the subducting Pacific plate. Two cycles of the recently active subduction in the Tonga-Kermadec island arc were found.  相似文献   

Crustal thermal models for South Siberia     

L. S. Sokolova  A. D. Duchkov  Reviewer V. Čermák 《Studia Geophysica et Geodaetica》1978,22(2):200-207

Summary The results of geothermal research carried out in South Siberia (West-Siberian and Siberian Platforms, Altai-Sayan folded area and the Baikalian arched uplift zone) were employed to calculate the Earth's crustal temperatures. It is shown that temperature is a function of the heat flow value. The maps of the surface heat flow and the temperatures at the Moho discontinuity are presented and characteristic temperature-depth profiles were compiled for specific tectonic areas. The West-Siberian and Siberian Platforms, as well as the Altai-Sayan folded region are characterized by rather low heat flow, 42–50mW m ^–2 (1.0–1.2 µcal/cm ² s), and low temperatures at the Moho boundary.400–500 °C. The thermal conditions in the area of Lake Baikal are extreme, the heat flow reaches here100–142 mW m ^–2 (2.4–3.4 µcal/cm ² s), and the temperature at the crust's bottom may exceed1000 °C. The Moho-surface according to our calculations is nonisothermal.  相似文献   

Electrical conductivity of rocks in the heating and cooling cycle     

Marcela Laštovičková  Reviewer F. Janák 《Studia Geophysica et Geodaetica》1978,22(2):184-189

Summary The values of the electrical conductivity, recorded during the heating and cooling cycle, of eclogites and basalts are compared. The observed difference in the values is explained by reversible and irreversible changes which take place in the samples.  相似文献   

Numerical modelling in laterally inhomogeneous geoelectrical structures   总被引：2，自引：0，他引：2  

Václav Červ  Oldřich Praus  Reviewer M. Hvoždara 《Studia Geophysica et Geodaetica》1978,22(1):74-81

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Dedicated to RNDr. Jan Pícha, CSc., on his 60th Birthday  相似文献   

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