On surface seismic waves formation

Summary The interpretation of surface seismic waves records is rather complicated as they include a superposition of oscillations of the fundamental mode and higher modes. Besides recorded oscillations depend on spectral characteristics of motions in earthquakes sources. The consideration of these problems is based on results of surface waves two-dimensional modelling [1]³. Some physical ideas about their formation deals with the change of the nature of the oscillation propagating with dispersion. This report represents a condensate of several independent works. , , . , . , . () . .Scientific communication presented to the IASPEI Assembly, Madrid, 1969.     

A note on secular variation of gravity due to non-tidal geodynamic phenomena

Summary Secular non-tidal variations of geopotential and gravity are estimated due to secular decrease of the second zonal geopotential harmonic, secular polar motion and deceleration of the Earth's rotation.

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am a nuu uunmuaa u u u mmu, a u m aauunmuaa, ¶rt;uu n u u mu au u.

     

The gravitational effect of bodies with variable density

Summary Determination of the gravitational effect of some bodies, the density of which is supposed to be variable in the vertical direction, possibly in the horizontal direction, too.

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n¶rt;uaumau ma m m, nmm m um mua uu muma anau.

     

On global short-periodic synchronous oscillations of the atmosphere

Summary The existence of global synchronous atmospheric oscillations with the period of about 1.4 hour is indicated in terms of a simple theoretical model of the circumpolar circulation.

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u nu nm mmu ¶rt;u un uuu naa maua au am nu¶rt; 1,4 .

     

On the estimation of the heat flow at the earth's crust lower boundary

Summary The paper deals with a comparison of two models used in determining the heat flow q_M at the lower boundary of two-dimensional geothermal models of the Earth's crust. Method I is based on a linear relationship between the component of the surface heat flow, which is not generated by heat sources inside the model, and the heat flow q_M. This method uses a regularization process, in which the variation of the sought function q_M is limited from above. Method II is the most frequently used iterative method, in which the (i + 1)-th approximation of q_M is determined from the surface heat flow, corresponding to the i-th approximation of q_M used as a boundary condition in solving the direct problem. The comparison of both methods has revealed that the solution obtained by method I satisfies the supposed reality better than the solution obtained by method II. Method II is attractive especially for its simplicity. To eliminate the local variations of the estimated heat flow q_M, which are due to automatic transmission from the surface heat flow, a combination of method II with some smoothing procedure could be applied.

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¶rt;am ¶rt;a m¶rt;a uu mn nma q_M a uau ¶rt; muu ¶rt; . m¶rt; unm u ¶rt; ma nm nma, ma uaa umuau mna mu ¶rt;u, u nm q_M. m m¶rt; nu n uauu, auuau auau u uu q_M . m m¶rt;, mu nm ¶rt; u n a , umau: (i + 1)-a annuau nma q_M um n auma nm nma, ma i- annuauu q_M. au ¶rt;m, m nm q_M, a¶rt; n m¶rt;, mam n¶rt;naa ¶rt;mummu , u, n m m¶rt;. m m¶rt; nuam nmm. ¶rt; mau a auau a¶rt; nma q_M, uu ¶rt;mu amamu na u auau nm nma, ¶rt;a uuam au-u¶rt; m¶rt; auau.

     

Closed formulae for transformation of the cartesian coordinate system into a system of geodetic coordinates

Summary Relations for the direct transformation of the Cartesian coordinate system into a system of geodetic coordinates.

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u ¶rt;u , , z ¶rt;uu , , h.

     

On the possibilities of horizontal propagation ofPc1 pulsations in the ionosphere

Summary The vertical distribution of the contribution of the energy flux density due to the Alfvén(ordinary) wave, guided by the geomagnetic field(and propagating through the ionosphere to the Earth's surface) in the horizontal direction is demonstrated in the mechanism of the horizontal propagation of the Pc1 signal. The distribution with height is shown of the variations of the polarization characteristics of the propagating wave(e.g. the rotation of the polarization plane, changes in ellipticity, attenuation, etc.), which are the result of coupling in the denser layers of the low ionosphere in which also suitable isotropic(extraordinary) modes are generated. The results obtained using the method described in[4, 13] are demonstrated on a model of the daytime ionosphere under incidence of ordinaryL-modes, frequency f=0.3 Hz, and various meridional angles at the ionosphere.

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auauma anmau uaa Pc1 naa m an¶rt;u ¶rt;u nmmu ma uu uma anauu maum n n¶rt; , anma u nmu. naa m an¶rt;u uu aamumu nuauu anma (nauau nmu nuauu, uu unmumu, amau u m.¶rt;.), m m ¶rt;mu au¶rt;mu na uu u . ¶rt; mum n¶rt;¶rt;u umn() ¶rt;. mam num m¶rt; [4, 13] ¶rt;mua ¶rt;u ¶rt; u nu na¶rt;uu a u L-¶rt; amm f=0,3 n¶rt; au u¶rt;uau au.

     

Travel times of seismic waves propagating to the bohemian massif from the south-west direction

mau x¶rt; u a¶rt;u 8 ¶rt;nu mau ¶rt; uu mu u -ana¶rt; auu naa num mam u u na n, g, Sn u Sg mum ma¶rt;am¶rt;a ¶rt; uu mu. a¶rt;u lam mu aua u umau u mm u a amuu ¶rt; En.     

Periodicity in the changes of the direction of the geomagnetic field

a au ¶rt;a a¶rt;u naam, m m uu anau n m aum u m u. aam u¶rt;a nuuu u u au am nmu m au. ¶rt;m nu¶rt;umu, m m m a mu u. n¶rt;mauau auumu aama u¶rt;a u um ¶rt; um aamu.     

Constraints to the three-dimensional non-hydrostatic density distribution in the earth

Summary The paper is concerned with the properties of a density distribution within the Earth. A system of density parameter constraints involving Stokes' coefficients of the gravity field and the parameters describing the Earth's figure is derived. A density model, whose parameters fit these constraints, accounts for the fine structure of the gravity field and Earth's figure. Additional condition imposed on the average spherical density model are derived; they guarantee that the average spherical model is compatible with the 3-D density model.

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aamuam ma an¶rt;u nmmu mu u. ¶rt;a uma u, auuau au naam nmm ¶rt;u; uma am m naamaumau n u naam nuau u u. mma ¶rt;, naam m ¶rt;mm mu auuau u, nm n¶rt;um uu umnmau m mmaumau n u u u. ¶rt; ma ¶rt;num u, aa¶rt;au a ¶rt; u ¶rt; nmmu, m nuam ¶rt;uu ¶rt; u ¶rt;u m nmm ¶rt;.

     

Simple model for long-range forecasts of AT500 hPa level fluctuations

Summary A forecast model to predict the fluctuations of level AT 500 hPa in a selected grid of points is derived. The solution of the compensation equation is sought in the form of a trigonometric polynomial in three idependent variables. It constitutes the basis of a numerical solution of the prediction problem with the use of a high-speed computer. A three-month forecast of the altitude fluctuation of level 500 hPa is evaluated by means of the daily values of the correlation coefficient. The results are satisfactory and the general evaluation shows the model to be prospective.

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¶rt;um nmua ¶rt; ¶rt; na au m AT 500a a uum m m. u au nauu um u¶rt; mu mu nua m m auu n. m u u nmu a¶rt;au a . u¶rt;um a m na au m 500a nu nu m au uuma uu. mam m anumu, u nu ¶rt; n¶rt;mam nnmu.

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List of symbols used * coupling coefficient between two conjugate atmospheric elements - * ageostrophicity coefficient of the atmospheric system - Coriolis' parameter (=2 sin) - , * geographic latitude, geographic longitude - *, geopotential reference and pressure levels - , * compensation and coupling frequencies - integration field over the entire atmospheric system - A** constant (A*=2 ²(*+*)) - A _r ,B _r ,C _r ,D _r constants related to subsystem -r- - A _s ,B _s ,C _s ,D _s constants related to subsystem -s- - B** constant (B**= ⁴(*²+2**)) - C _r constant (i=1, 2, 3, 4) - E _k ,E _v ,E _p energies of the atmospheric system: kinetic, internal and potential - K transformation constant - m total number of generalized frequencies - R(T) frequency characteristics of the numerical band filter - r0(t),r1(t) daily values of the correlation coefficient - Q heat - x, y coordinates in the reference plane - t time - _p ² Laplace's differential operator in thep-system     

Single- and inter-station transfer functions for non-synchronous geomagnetic arrays — I. Theory of methods used in data analysis

Summary The theory of the multivariate coherence analysis(spectral domain approach) is developed for calculating single- and inter-station transfer functions and corresponding vector induction characteristics from time variations of the geomagnetic field components. An alternative approach of calculating similar induction characteristics using a time domain algorithm is shown.

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aam mu m aaua(nma n¶rt;¶rt;) nuuu ama ¶rt;-u -mau n¶rt;am u u mmmu m aamumu u¶rt;uu n anua auau mau aum n u. u¶rt;um ma m¶rt; u aau aamumu u¶rt;uu nm ama amu un mua um. nuam aum na auu am u aamum ¶rt; n ama naam.

     

Macroseismic observations of earthquake in Yugoslavia (April 15, 1979, 06h21m gmt), on the territory of Czechoslovakia

an¶rt;u am mu 15- an 1979. a auu a mumuu auu.     

Three-component spectral analysis of geomagnetic pulsations

nua m¶rt; nma aaua a, umua m nma, m n¶rt;um umau nuau un nmam. m¶rt; annua aaum nauu Pi2 u Pc3 u amu u u ¶rt;. ¶rt;a ma m ¶rt; nmam nuau aamumu u u auum m aum amumu.     

Stratospheric ozone variability near the IMF sector boundary

Summary We search for the effects of the interplanetary magnetic field (IMF) sector boundary crossing (SBC) in upper stratospheric ozone. The SBUV data (Nimbus-7) at the 10, 3 and 1 hPa levels are analysed for latitudes 45° N and 55° N for winters of the period December 1979 to December 1982. An effect of the IMF SBC wos only found at the 10 hPa level. These first results concerning the IMF SBC effect in upper stratospheric ozone are rather preliminary.

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¶rt;m uu nu mau () nam aum n () a mam. SBUV ¶rt;a (u-7) a nm ¶rt;au 10, 3 u 1a aauum ¶rt; um 45° u 55° . . ua nu¶rt;a ¶rt;a 1979 – ¶rt;a 1982. m uu a¶rt; m a 10a. mu n mam n uuu a mam m n¶rt;aumu.

     

The four primary geodetic parameters

Summary The four primary geodetic parameters defining the geodetic reference system are discussed from the point of view of their physical meaning and current estimation of their actual accuracy. The geopotential scale factor has been treated as the primary geodetic parameter defining the Earth's dimensions.

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¶rt;am m nu¶rt;uu naama, n¶rt;u¶rt;u um mumu, mu u uu a u mmu. ama amnmuaa ¶rt;am am nu¶rt;u naama, n¶rt; a u.

     

Magnitudes of detectable and localizable shocks in nw bohemia

Summary The effectiveness of recording seismic phenomena in the Kruné hory (Mts.) region in NW Bohemia by selected stations in the CSR, GDR and Poland has been estimated. Magnitude isolines of the weakest earthquakes, which can be localized and detected with an 0.9 probability, were calculated on the basis of the level of seismic disturbances at the individual stations and of the empirical dependence of the attenuation of seismic waves with distance.

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a a mum umauu uu u amu ¶rt; ana¶rt; uu uau mauu a mumuu , u a a uu n a m¶rt; mau u nuu auumu amau uu m amu u auma uuuu aum¶rt; a a mu, m mm 0.9 auuam u aum.

     

Explanation of the internal air pressure effect on the worden gravity meter dial constant

Summary A model, explaining the effect of air pressure changes in the space of the measuring system on the fine dial counter constant of the Worden and similar gravity meters, is presented. It is based on the changes of the bellows volume with compensating the gravity changes. It is shown that the resetting the gravity meter in the whole range has practically no influence on the fine dial counter constant.

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u¶rt;a ¶rt;, na m uu ¶rt;au ¶rt;a nmam uum um a nm a umaauma ¶rt; u nuaum. ¶rt; aa a uu a ua umu uma nu nauu uu u mmu. aa, m nma ¶rt;uanaa um namuu um a uu nm a uma.

     

On the possibility of utilizing grid reports in a local model of short-range forecast of meteorological elements

Summary In the experiment described, we test the possibility of utilizing forecasts of the pressure field, contained in GRID reports, to solve the problem of horizontal boundary conditions of a local model of short-range forecast of meteorological elements. We prove that the assumption of a linear tendency of the prognostic variables in the boundary region yields good results, using the Perkey-Kreitzberg method[1], even if applied to period T=24 hrs. In the Perkey-Kreitzberg method the effect of the horizontal diffusion in the boundary region is suppressed[2]. However, considering the diffusive term apart from the procedure of the method mentioned proves detrimental to the forecast.

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nua num n m unau n n ¶rt;au, ¶rt;au ¶rt; ¶rt; u numaau u a ¶rt;u am na muu m. aam, m n¶rt;nu u m¶rt;uu nmuu n au amu nu unauu m¶rt;a u- [1] ¶rt;am u mam ¶rt;a nu nuuu nu¶rt; T=24 a. m¶rt; u- nu¶rt;um n¶rt;au uuuma ¶rt;uuu au amu[2]. ama ¶rt;u a n¶rt; nu¶rt; m¶rt;a nu¶rt;um, ¶rt;a, ¶rt;u n.

     

On the non-tidal secular acceleration of the Earth's rotation

Summary The secular positive acceleration of the Earth's rotation has been computed on the basis of the observed secular decrease of the second zonal harmonic[5]. It corresponds to the observed secular deceleration of the Earth's rotation which should be greater because of oceanic tides.

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¶rt; u a¶rt;a u m aauu [5], u ¶rt;a num u au. m mmmu a¶rt;a u mu au u, m.. n¶rt; n m uu , ¶rt; m n auu nuua.