Space-time ray method for seismic wave fields     

Vlastislav Červený  I. A. Molotkov  Ivan Pšenčík  Reviewer J. Vaněk 《Studia Geophysica et Geodaetica》1982,26(4):342-351

Summary The space-time ray method can be applied to the evaluation and continuation (extrapolation) of the complete seismic wave field in laterally inhomogeneous media with curved interfaces. The wave field propagates along certain space-time curves, called space-time rays. Their space projections correspond to standard rays. Examples of possible applications of the space-time ray method, where the standard ray method fails, are as follows: a) The propagation of seismic waves in slightly dissipative media, b) The computation of seismic wave fields generated by seismic sources with direction-dependent source-time variations. c) Downward continuation of the seismic wave field (actual seismograms) measured at the Earth's surface.  相似文献   

Effect of hydrostatic pressure upto 1.5 GPa on the magnetic parameters of basaltic rocks     

Zdeňka Podroužková  Aleš Kapička  Reviewer M. Krs 《Studia Geophysica et Geodaetica》1982,26(1):59-65

Summary The effect of hydrostatic pressure upto 1.5 GPa on the remanent magnetic polarization of samples, representing three groups of basalts with different ratios of the reversible and irreversible component of overall changes is studied. It is shown that, as a result of permanent changes of the transfer properties of the non-magnetic matrix, the patterns of pressure changes of the remanent magnetic polarization differ after applying a pressure of 1.5 GPa, however, the ratio of the reversible and irreversible component does not change.  相似文献   

Outer-zone electron boundary according to intercosmos-13 measurements     

Karel Kudela  Ján Matišin  Reviwer S. Fischer 《Studia Geophysica et Geodaetica》1982,26(1):102-106

Summary The position of the high-latitude boundary for electrons of E_e>40 keV and E_e>1 MeV on a low-altitude satellite is studied. An assymetry of this boundary with respect to magnetic local time has been detected. This assymetry depends on geomagnetic activity. Changes of boundary position are more pronounced for lower energies than for higher. The boundary positions obtained by Intercosmos-13 are compared with those obtained by the OGO-6 and AZUR satellites.  相似文献   

A method of reducing the disturbing effects in gamma — Spectrometric measurements of rock radioactivity     

Milan Krešl  Věra Vaňková  Reviewer J. Buben 《Studia Geophysica et Geodaetica》1982,26(1):66-73

Summary The long-termed stability of the NTA 1024 Gamma spectrometer was investigated. In order to reduce the influence of the instability of the linear amplifier, a method of mathematical transformation of the spectrum was introduced.  相似文献   

Modelling of the sensing system of a vibrational magnetometer by digital computer     

Tomáš Zelinka  Pavel Hejda  Josef Bochníček  Reviewer F. Janák 《Studia Geophysica et Geodaetica》1982,26(3):272-280

Summary An analytico-numerical computation of the transfer function of the sensing system of a vibrational magnetometer is presented. In discussing the results, the properties of the method are pointed out and a proposal for the sensing system is made with regard to the required sensitivity of the instrument.  相似文献   

Tilts due to the free nutation of the Earth's axis in the results of geodetic observations     

Antonín Zeman  Reviewer M. Burša  Reviewer M. Pick 《Studia Geophysica et Geodaetica》1981,25(3):284-288

Summary Simple expressions for the deformation of equipotential surfaces and changes of the deflections of the vertical are derived at points of the Earth's surface, which are due to the variations of the rotational component of the gravity potential under free nutation of the Earth's axis of rotation (pole wandering). The results of the solution of this problem given in[1] are discussed. The values of the tilts and the changes of geoid heights for extreme deviations of the poles are considered from the point of view of the effect on measuring tilts and on levelling. An elastically deformable Earth is assumed. It is concluded that reductions with respect to the mean Earth's pole are not realistic at the present degree of accuracy of levelling. The necessity to reduce long-term tilt observations, or the possibility of determining the time variations of the rotational axis from the analysis of these observations is pointed out.  相似文献   

Bewölkung über Mitteleuropa nach den Satellitenaufnahmen     

Aleš Gottwald  Rezensent J. Pavlik 《Studia Geophysica et Geodaetica》1981,25(4):413-415

Zusammenfassung Es wurde u.a. festgestellt, dass in der fünfjährigen chronologischen Reihe der Bewölkungsgrade Mitteleuropas mehrere Perioden vorkommen. Es wird angenommen, dass die 28–29-Tage-Periode von solaren oder lunaren Einflüssen hervorgerufen sein könnte. (Dieser Kurzbericht stammt aus dem ausführlicheren Text des Vortrages, der an der wissenschaftlichen Tagung im Institut den 8. 12. 1977 vorgelesen wurde.)  相似文献   

Possible differences between mean sea-levels from satellite altimetry     

Milan Burša  Zdislav Šíma  Reviewer J. Picha 《Studia Geophysica et Geodaetica》1981,25(1):1-4

Summary The first attempt has been made at determining the differences between mean sea-levels, using the recent satellite altimetry data [1].  相似文献   

On the problem of equal area block on a sphere     

Karel Klíma  Miloš Pick  Zdeněk Pros  Reviewer M. Burša 《Studia Geophysica et Geodaetica》1981,25(1):24-35

Summary A new untraditional way of dividing the sphere surface into an arbitrary number of equal area blocks by means of a spiral is proposed and its statistical properties are analysed.  相似文献   

Chemical speciation of trace metals at the air-sea interface: The application of an equilibrium model     

Leonard W. Lion  James O. Leckie 《Environmental Geology》1981,3(5):293-314

Air-sea interfacial solutions have characteristically high concentrations of trace metals, microorganisms, organic compounds, and solids relative to bulk solutions. The potential for the chemical interaction of an array of trace metals in the interfacial regions with complexing organic ligands and adsorbing solid surfaces has been evaluated through the use of an equilibrium computer model. Computations suggest that higher interfacial accumulations of copper and lead may occur relative to cadmium and mercury. These results are found to be generally compatible with available field data describing trace metal interfacial accumulation. The forms of metals found to be partitioned between bulk and interfacial solutions are consistent with the hypothesis that solid surface adsorption and dissolved organic complexation reactions bring about metal enrichment at the surface microlayer.  相似文献