Fast computation of ray synthetic seismograms in vertically inhomogeneous media

Summary A procedure of fast computation of body-wave ray synthetic seismograms in vertically inhomogeneous media is suggested. The procedure uses a special approximation of the velocitydepth distribution which guarantees continuity of the first and second derivatives of velocity and does not generate false low-velocity layers (oscillations in the velocity-depth function). The ZESY82 program package, which is based on the suggested procedure, is described. The point source with an arbitrary radiation pattern may be situated at any points of the model, the receivers are situated regularly or irregularly along any profile on the Earth's surface, containing the epicentre. Numerical examples of the synthetic record sections for a model of the Earth's crust and the uppermost mantle are given.

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¶rt;aam m¶rt; m ama ummuu a mua ¶rt;¶rt; ¶rt;, u¶rt; u nua annuauu m aa, ma nuam nm mu u n u m nu¶rt; u nu¶rt;um aau um nu mu. am nua aumn na ZESY82, a a m m¶rt;. umu aamumu uu an m ¶rt;u; nuuu ¶rt; m an¶rt; ¶rt; nu, ¶rt;a num. u¶rt; nu ummuu a ¶rt; ¶rt; ¶rt;u u amuu.

     

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.     

Some results of the comparison of Courvoisier,Schulze and Yanishevsky balancemeters

Summary Courvoisier, Schulze andYanishevsky type balancemeters have been compared in field exposure under different weather conditions and in the laboratory. Special attention has been devoted to the selectivity and the temperature regime of the detectors. The installation of the instruments is described and the main results of simultaneous measurements with the above-mentioned balancemeters are presented. , . v . .     

A contribution to the parameterization of total radiation

Summary To be able to parameterize vertical heat and water vapour fluxes in the boundary layer of the atmosphere, it is necessary to determined, among other factors, the amount of incident total radiation under a generally arbitrary condition of the atmosphere at any instant of time. This paper deals with a simple model for computing the total radiation based on known solar elevation, total cloud cover and the atmospheric turbidity parameter. This variant of the model was formulated on the basis of a two-year series of total radiation observations made in the radiation network of the Czech Hydrometeorological Institute, and on the measurements and observations made at the observatory of the Institute of the Physics of the Atmosphere in Kopisty. An example of comparing the observed and theoretical values of total radiation will also be given.

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¶rt;um naamuauu mua nm mna u amu nzau am mm ¶rt; nu n¶rt;u au a nm numa a a¶rt;uauu m u. mam auam n naamuauu a a¶rt;uauu n ¶rt;a m a, ammu am u mnu az na. ¶rt;azaa ¶rt; nma a mam ¶rt;mu uu auau mu z zu¶rt;mzu z umumma u a amuu mumma uuu am numa. mam ma nu¶rt; nu au u u n n¶rt; ¶rt;u u au a a¶rt;uauu.

     

Iterative geophysical tomography

Summary The algorithm of iterative geophysical tomography is presented. The medium is approximated smoothly by means of B-splines. The tww-point problem of ray computation is solved with the aid of paraxial approximation. The parameters of the medium are obtained from the iterative algorithm of minimizing the quadratic form. Two numerical 2-D examples are given.

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u¶rt; au umamuuu mauu. ¶rt;a annuuaa n nu nu -na. ma na aa a nu nu naaua annuauu. aam ¶rt; n a umamu aua uuauauu a¶rt;amu . am nu¶rt; ¶rt;a 2-D u nua.

     

Motion of particles in turbulent flow: Hyperbolicity,strange attractors and dynamic stochasticity of a system

¶rt;naa, m ma um uu maunuu m am muu ¶rt;uauu um. nua a mau ammama a, n¶rt; mnu ma u u au uu u¶rt;mu.     

Electrical conductivity of some rocks from the Indian subcontinent

Summary Results on electrical conductivity, chemical analysis and age of the rock samples from the Indian Subcontinent are presented. The old Precambrian Indian rocks tend to be less conductive than characteristic rocks of crustal and upper mantle structures.

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nuam mam uu mnm¶rt;mu, uu aaua u n¶rt;u u uu n¶rt; u ¶rt;uu. ma nauu n¶rt; u ¶rt;uu naam mn¶rt;m aamumuu n¶rt; u amuu.

     

Consequences of transducer inductance for seismograph calibration

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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ma¶rt;ama auau aa nu ¶rt;uu ¶rt;uu maauu m m m a u amma ua u a au u¶rt;mumu ¶rt; ua u auau am, u u a¶rt;m n¶rt;m umu. a ¶rt;aa nnma muam auau ¶rt;a. uu mmuu au u¶rt;a nu auauu mnu¶rt;u aa u anu.

     

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.     

The response of the total electron content to the interplanetary magnetic sector boundary crossing

¶rt;m uu n ¶rt;au m uu nu mau nam aum n. mu uu auam mmmuu uuu ¶rt;u u naam. a¶rt;am auu ¶rt; uuu n ¶rt;au m u u. a auu a¶rt;am nuu amm 245 . ¶rt;aam umnmau m a¶rt;a uu.     

On the further generalization of trochoidal frontal waves

Summary A non-linear model of trochoidal waves is presented which represents a geometrical and kinematical generalization of Gerstner's waves and of the results of[2–4].

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¶rt;aam ¶rt; mu¶rt;a , ma m u ma u am[2–4] mu umuu u uamu mm ¶rt;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.

     

Statistical analysis of values measured in condensating geodetic nets

Summary Procedure for verifying the agreement between parameters common to the basic and connecting trigonometric net. Procedure of determining the accuracy of the connecting net. This determination concerns not only the relativized accuracy of the points of the connecting network, but also the mutual accuracy of the points of the basic net relative to the points of the connecting net and the global accuracy of the resultant net. The procedure takes into account the accuracy of the points of the basic net which remain unchanged in computing the coordinates of new points.

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m¶rt; ¶rt; nu au u naam¶rt;mu u nu¶rt;u m. m¶rt; ¶rt; u mmu nu¶rt;u mu. a aam m mum nua mmu m nu¶rt; mu, ma au mmu m mu n mu ma nu¶rt;u mu ua mmu mu mu. m¶rt; umam mm m mu, m aa uu ¶rt;uam m mam uu.

     

Precession-nutation torque in terms of the stokes constants

um nu-mau m nuuau u auumu m nm ma u. m mu u¶rt;uu¶rt;a m ma nuua u uu.     

Definition of the normal gravity field including the constant part of tides

Summary One alternative of solving the problem of eliminating the effect of external masses, generating the constant part of the tidal field, from the perturbing potential is presented. The solution is founded on a new definition of the normal gravity field which contains this part of the tidal field. It is proved that two material circles in the plane of the Earth's equator, whose radii are approximately equal to the mean distances of the Moon and Sun from the Earth, can be considered as the source of this field. The new normal gravity field is first derived in the spherical approximation, which enables one to prove simply that the value of the normal gravity potential on the reference surface does not change, and that the change in the definition of the heights is insignificant. The normal gravity field for the equipotential ellipsoid is derived in the same way according to [1].

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¶rt;mam ¶rt;a amamua u ¶rt;umua n uu uu u a, au nm am nuu n, u a nmuaa. u a a n¶rt;uu a n u mmu, m m am nuu n aam. aam, m am umua m n umam a ¶rt; m nmu ama, a¶rt;u m nuuum a ¶rt;u amu u a m u. ¶rt; ¶rt; a n u mmu u nuuuu, m nm nm ¶rt;aam, m au a nmuaa u mmu a nmu m u m uu n¶rt;u m aum. ¶rt;ua n (. [1]) ¶rt; a n u mmu ¶rt; unu¶rt;a.

     

Preparation of input data,inclusive of satellite data,for forecasting precipitation within a limited area

Summary The inclusion of cloudiness characteristics, obtained by computer analysis of multispectral satellite photographs, in the objective analysis of the dew-point temperature deficit is suggested for the mesomodel. The basic principle of the method is the correction of mathematically packed data using processed satellite cloudiness observations. Special fast algorithms for constructing bicubic splines are used to effect the basic mathematical packing.

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¶rt;aam m¶rt; ¶rt; u aamumu a na ma n aaua nma nmu u nu nu uum au mu aau ¶rt;uuma mnam mu ¶rt; ¶rt;u. m¶rt;a m u amamuu nm ¶rt;a nu nu nmu u. aau ¶rt;a unm nua m aum ¶rt; muu uuu na.

     

The optimal shape design method applied to modelling thermal thinning of the oceanic lithosphere near hot spots

Summary Using the optimal shape design method, which is generally described, and von Herzen's et al. measurements of the heat flow, the shape of the lithosphere and its thermal field is computed in the vertical plane parallel to the hot spot source versus the plate velocity at a distance of about 250 km from the axis of the Hawaiian Island chain. The results are compared with the computations based on Crough's idea of thermal rejuvenation of the oceanic lithosphere above a hot spot source. If we assume that the lateral cross-section of the lithospheric bottom is described by the Gaussian curve h=h₀ exp (–y²/2²), we obtain h₀35 km and 130 km, where h is the value of lithospheric thinning and y the lateral coordinate. We thus obtain the lower limit of the lateral dimension of the Hawaiian anomaly.

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u m¶rt; nmua nua amu, m u ma nuam, u ¶rt;a mn nm, ua a um u mn n mua nmu, naa mu um mum umua mu u ¶rt;a nuuum 250 m uuuaa aunaa. mam a uuu, au a u¶rt;u aa (Crough), aauu mn mu au um a¶rt; umu mu. u n¶rt;num, m ama nn u umu ¶rt;a nuam u aa h=h₀ exp (–y²/2²), m num h₀ 35 u 130 ,¶rt; h—umu mu u —amaa ¶rt;uama. ¶rt;am, =130 m u n¶rt; ama aaaa aauu.

     

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 .

     

Periodic fluctuations at frequency of the nearly diurnal free wobble in Ondřejov PZT observations

Summary The regular astronomical determinations of the geographic latitude and UT from Ondejov PZT observations were used to estimate the fluctuations with a frequency of 1.00217 of the sidereal day, corresponding to the theoretical value of the frequency of the nearly diurnal free wobble of the pole. The combined polar wobble and nutation as reflected in astronomical observations was analysed, and a method of estimating the amplitudes of the periodic components, based on observing changes of latitude and time during the separate observation nights, is proposed. The numerical solution indicates that fluctuations which can be considered a manifestation of retrograde free nutation with an amplitude of approximately 0.02, are present in the PZT observations.

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uuau um u u u ¶rt; una ¶rt; u au amm 1,002 17 ¶rt; m, mmm ¶rt; um ¶rt;uu na, ¶rt;am aau uu ¶rt;u mauu u ¶rt;uu na amuu a¶rt;u. ¶rt;aam m¶rt; ¶rt; u nu¶rt;uu ua, u¶rt;u u uu um u u m¶rt; a¶rt;u. u mam u¶rt;um a ¶rt; um mauu anau nmu ¶rt;uu a mu anum¶rt; 0,02.

     

Release test with electromagnetic seismograph

u¶rt; am ¶rt; mua maum aa nu ¶rt;uu ma n¶rt;a mnu ma auau am. a¶rt;¶rt;a mu m¶rt; auu a¶rt;am n¶rt;um m nm aa u n uu naua nu¶rt;a ma uuaama aumam ma nm aa u uu uuma u.