The computation of the elastic constants of an anisotropic medium from the velocities of body waves

¶rt;m n¶rt;u nu nm n m . m¶rt; n¶rt;am nuuu am uma au muna (6) u (10). amua aumnu m m nn unam u u, m nmu ama mm (u. 2). uu nu nm ¶rt;u am mu n¶rt; uua 15mu anau u mu u nn uua mu anau. u unauu m nn ¶rt;u am mu n¶rt; uua ¶rt; 21 anau.

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Dedicated to 90th Birthday of Professor Frantiek Fiala     

Solar activity variations and climatic changes

Summary For the last two millenia it has been possible to determine the secular variation of solar activity from naked-eye sunspots, aurorae and radiocarbon variations. The results of the analysis of old East Asian observations of comets, which reflect the night cloudiness variation, do not agree with the former findings that the long-term climatic changes derived from comets depend on solar activity. The distinct anticorrelation between the Chinese records of comets and naked-eye sunspots is found only for the period from the 3rd to 6th century A.D., but in other centuries any correlation can hardly be seen. East Asian cometary observations give evidence of climatic changes in different parts of this large geographic region.Secular variations of the River Nile levels, regularly measured from the 7th to 15th century A.D., clearly correlate with the solar variations, which suggests evidence for solar influence on the climatic changes in the East African tropics. The decline of the Kingdoms in ancient Egypt and the occurrence of the Intermediate Periods are generally explained by very low Nile floods and prolonged droughts followed by severe famines and the destruction of the political structure. But the radiocarbon data show that at least the First and Second Intermediate Periods coincide with the secular maxima of solar activity and the Middle Kingdom with the minimum. This contradicts the positive correlation found from the eight centuries of measurements of River Nile levels made by Arabs. It seems that the influence of solar activity on the secular climatic changes has an episodic character.

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nu¶rt; uu amumu ¶rt;mam m n¶rt;um nuuum a n¶rt;u ¶rt;a mmu nm au nu n uu u u¶rt;u a nm a¶rt;u¶rt;u uuu. ¶rt; amm nu n uu uu n mmu .. um a m uu ¶rt;a umumuaum n. ¶rt;m auau nu m amum ua a uu amumu a am — am, maau ¶rt;nu¶rt; uamuu uu. ¶rt;a, mam aaua ¶rt;u a¶rt;u m u n a a m am muu ¶rt;au. aua ¶rt;umau anuu ma u u¶rt;u a nma, aum amuu m ¶rt; nu¶rt;a - n 6- , a ¶rt;u nu¶rt;a maa u mmmm. m, aa uu uu mmmu uu ¶rt; ¶rt;au a¶rt;uu m uma, u nuu u¶rt;ummm auuu uu uama au am m au amu.nu¶rt; auauu m n¶rt;a ¶rt; (au), a ma ma aa ma ¶rt; (uu) u n uu, n¶rt;uu u unm ¶rt;u 7- ¶rt; ¶rt;u 15- a, n¶rt;u auau. m u¶rt;ummm uuu a a uamuu uu m-auau mnua. a u u numu aumu ¶rt;unmu am m au ua nuaa. na¶rt; ¶rt;unmu am u amnu ¶rt;amu m uu ¶rt; u u n¶rt;umu aau, a mu n¶rt;a m¶rt; u au numu mm. ¶rt;a, n a¶rt;u¶rt; ¶rt;a aum, m n a n u m ¶rt;amu na¶rt;am ¶rt;umu auau amumu, m nmuum num uu, ¶rt; u ummu uu ¶rt; u. am, m uu amumu a uu uama um aa nu¶rt;u aam.

     

Determination of the gravitational effect of extensive spherical laminae (platforms) using generalized Talwani's method

u uuuuaumau uu u m, ¶rt;u a mumau nmu a u nmu mau u nmmu. au n¶rt; nuau ¶rt;mam u u m. nua m¶rt; m u m¶rt;a aau (1960) ¶rt; uu .     

Analysis and optimization of wide-band force-balance seismometer responses

¶rt; aau n¶rt;am uu, umu,au mummu u ¶rt;uau ¶rt;uanaa mu um. am n a nmua amm aamumuu um ¶rt; au uu nuu. ¶rt;ma ummuu m¶rt; nmuau mu um a a¶rt;a an¶rt;u n n¶rt;am uu n nmu.     

Density inhomogeneities in the upper mantle of Central Europe and their gravitational effects

Summary Problems of occurrence of density inhomogeneities in the upper mantle are discussed and their gravitational effects in the region of Central Europe are investigated. Attention is namely devoted to the density contrast between the asthenosphere and the lower lithosphere, and its possible dependence on depth.

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¶rt;am n nu nmm ¶rt;¶rt;m amuu u uaumau ¶rt;mu a mumuu ¶rt; n. uau ¶rt;m n¶rt; nmm mam ¶rt; am u um u auumu mu aau.

     

Intensity of vlf and elf phenomena in the outer ionosphere

Summary Spatial and temporal variability of natural ELF-VLF phenomena field intensity has been studied using data from Interkosmos satellites with apogees below 2000 km. The results show a distinct dependence of the diurnal variation and latitudinal intensity distribution on the magnetic activity. The L-value at which the maximum of plasmaspheric noise occurs, e.g., correlates better with the Dst-index than with other indicies.

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mama u a auau anmu n mm - u a ua a uu ¶rt;a uu m an u 2000 . mam naam m auum m ¶rt;a u um an¶rt;u uu m aum amumu. uua L-naama, a m nm au naa uu, um Dst-u¶rt; ¶rt;uu u¶rt;auaum amumu.

     

On the general theory of equivalent projection

Summary The paper deals with the general theory of equivalent projection. By specifying the results derived, special cases may be treated. Examples of methods are described which enable free functions to be found in a general solution. A detailed procedure of solving the problem with a numerical example is given, taking into account the optimization according to the global criterton, established for extreme angular distortion.

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aamuam a mu auu nu; ¶rt;am m am au. nu m¶rt;, nu amu ¶rt; uu uu. umam nmuauau n aamumu au, ma ¶rt; aua uau , u nuam n¶rt; m¶rt; u u nu.

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Dedicated to Professor Frantiek Fiala on the Centenary of his Birthday     

Analysis of the magnetometric vibration method

n¶rt;m mu ¶rt; mu uau aumma. mu aum u mu u m u mu auauu m¶rt;a. u¶rt;m u naam nm nmmuna uau aumma.     

Study of the velocity conditions in the earth's crust in the regions of the Bohemian massif and the carpathian system along international profiles VI and VII

u¶rt;m n uu ¶rt;u m n u ma n¶rt;aa, nu m¶rt;u u ¶rt;uau. n nuu uu ¶rt;u m n ¶rt;a¶rt; nu NoNo VI, VII. u au u n m a (x, H), ¶rt;auu an¶rt;u ¶rt;u m ¶rt; m¶rt; nu, u mua m nuu (H), aamuu an¶rt;u m a mua ¶rt;¶rt; uu ¶rt;uua u a. u a ¶rt;u m (x, H) amm ¶rt;uuu (u) a m¶rt; nu. m¶rt; u, auuu aau, om aamuam muau an¶rt;u ¶rt;u m, uu , n m u m nu aamuu a nmu, am ma a¶rt;am aa uu ¶rt;u m. aa u a¶rt;u n nu NoNo VI u VII u umuu ¶rt;a. mua m nu (H) num m ¶rt;u amu aua u anam um, ¶rt;a amu ¶rt;aua u ¶rt;- nma (nu No VII). ma ¶rt; ¶rt; aua, maa numa nm m u numa nm ma¶rt;um, a unaa nuu umnmauu a¶rt;uu ¶rt;uau amu aua.     

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.

     

Transformations of spherical harmonics and applications to geodesy and satellite theory

am ¶rt; mauau uu u u aamuam u a. m num u m a¶rt;a muu nmuaa u ¶rt;uau nmu¶rt;uu.

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Invited Paper, 9^th Brazilian Congress in Cartography, Curitiba, Paraná, Brazil, February 4–9, 1979.     

Approximative ray tracing and the accuracy of earthquake localization in media approximated by block structures

Summary Localization errors made by approximating a given medium by a homogeneous rectangular block model and due to the approximative solution of two-point ray tracing are estimated for four different structures. The separate influence of the individual characteristics of the medium is discussed. The iterative Geiger method supplemented by a generalized inversion of the damped least-squares and Marquardt algorithm is used for localizating five hypothetical hypocentres using 9 stations. Travel times in the original structures, used as input data for localization, are calculated using a special ray tracing system.

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am uu auauu a annuau a ¶rt; ¶rt; ma u ma ¶rt;¶rt; u annuau m a ¶rt; munau nuuum .

     

Some results of investigating the electric field with the interkosmos 10 satellite

¶rt; aau ua au u¶rt;a, umu a nmu m-10 n uum mau mu n (). am au ¶rt;uana amm. aa ¶rt;¶rt;auma umnmau uuu u, auau nu ua au u¶rt;a.     

Stresses and displacements due to a stationary point source of heat in an elastic halfspace

am amu ¶rt; ¶rt; mnu annu u u, a maua m umu mna n nnmam. a auu uu naa, m uau anu m anuu amua muna u am am u n ummamuu anu uu nmu nnmama. auum m¶rt;uauu ¶rt;mu ¶rt;mu mau anu, ammu: a) ¶rt;mu um numa amu umua mna; ) m uu uu nm aa u u u nu uuu aa nuu a nmu u; ) aau amuau anu ammuu aau, m m nm u¶rt; n u amumu um mu am.     

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.

     

Predictions of magnetic fields for Uranus and Neptune

Summary The magnetic moments of Uranus and Neptune have been predicted using different scaling laws of planetary magnetism. The predictions for Uranus cover a broad band of values from very weak magnetic fields (tidal relations) to moderate fields (thermal convection hypothesis). Therefore, the direct measurements of this field by Voyager 2 (January 1986) will be very important for testing the individual hapotheses.

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a m ama a ¶rt; amua nam ¶rt;a n aum m nam a a nm. aa n¶rt;nmu nuu mu, ¶rt;m u¶rt;am a aum n a nmu aa u u a nmu nma.

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Presented at the Fifth Scientific Assembly of IAGA in Prague 1985.     

Transfer impedance of a probe in a drifting plasma

au un¶rt;a umu ¶rt;a na nu nauuu ¶rt;a uam mmu amm na aa. amau aa auum m mnam u mu ¶rt;a, m unam ¶rt; ¶rt;uamuu u na.     

Einige Bemerkungen zur Problematik der Spektralanalyse

auam uu ma¶rt;am m¶rt; un ¶rt; nu nm omu mamuu ua. a m n¶rt;aam u aum, m ¶rt; nua a nmuuuam. mm aum ma ¶rt;nam aau maua ua.

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Vorgetragen auf dem KAPG-Seminar Geomagnetische Pulsationsindizes, Niemegk//DDR, September 1977.     

Variations in the Earth's rotation and crustal deformations

a mmuu ¶rt; ¶rt;au nm u , a auauu ma mu au u. aamuam m¶rt; a, ma u mua mu ¶rt;au u ¶rt;aa u uma a; m a mu ¶rt;auu m ¶rt;muam 10% m ¶rt;au, a u nuuau m .     

Magnetic anisotropy of polycrystalline haematite induced by A D. C. magnetic field

Summary The changes in the anisotropy of initial susceptibility of haematite ores, induced by a D.C. magnetic field are studied. After applying stronger magnetic fields, the changes in the anisotropy parameters are considerable and depend on the manner in which the basal planes of the haematite grains are arranged in the samples. The experimental results are interpreted on the basis of the single-domain theory. The proposed simple model of induced anisotropy is based on the relation between the directional susceptibility of the sample and the preferred orientation of the magnetic moments of the grains in polycrystalline haematite.

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am uu aumnuu aa nuuumuamum ¶rt;, a nm aum n. nuu u aum n uu aumnuu aam u aum m na n¶rt;u nmamum aa. numa. ¶rt;a umnmua unau ¶rt;¶rt; muu. ¶rt;a nma ¶rt; a aumnuu aa a auumu u nuuumu m umauu aum m nuumauamum.

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Presented at the 5th Scientific Assembly of IAGA in Prague 1985.