Thermo-elastic deformations due to the annual temperature variation at the tidal station in Vyhne

Summary The thermo-elastic deformations due to the annual temperature variation are computed. The time variation of these deformations is compared with the variation of the slow deformations observed at the tidal station in Vyhne.

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u mnu ¶rt;auu, a¶rt; auau mnam nmu a nnmama. ¶rt; mu ¶rt;au a ¶rt; ¶rt; ¶rt;au, u a nuu mauu ().

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Dedicated to RNDr Jan Pícha, CSc on his 70th birthday     

Optimization of determining the additional constant of an electronic distance meter

Summary The optimization of the method of determining the addition constant of an EDM is discussed. The advantages of the optimization procedure from the point of view of efficiency and improvement of accuracy are reported.

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nuuu ¶rt; n¶rt;u a¶rt;¶rt;uu n ¶rt;. u nu n u uu u nu u.

     

Effects of the IMF pro- and anti-sectors in the winter midlatitude ionosphere

Summary On the basis of the 1966–73 data, the effect of the difference between pro- and anti-sectors of the IMF is found to be negligible in the winter midlatitude (Central Europe) ionosphere contrary to the dominant effect of this difference in the high-latitude ionosphere found earlier.

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a ¶rt;a a 1966–73. u¶rt;m u m amu ¶rt; pro- u anti- mau . na a u ¶rt;um (¶rt; na) u, , a naa a, naum um u.

     

A more precise mechanical theory of askania gravity meters

Summary The measuring systems of Askania gravity meters are assumed to have 3 degrees of freedom. The axis of rotation of the beam can also be displaced in the vertical and horizontal directions. The equations of equilibrium of this system (25)–(27) were used to derive the expressions for the effect of displacing the calibration ball, for the scale equation and for the sensitivity of the gravity meter. Equations (33), (34) and (39) refer to gravity meters with a photoelectric transducer, and Eqs (46), (47) and (49) to gravity meters with a capacitive transducer.

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uum umaum au n¶rt;naam 3 mnu ¶rt;. au aa m m nam mua uuma anau. au au m um (25)–(27) ¶rt; au ¶rt; ¶rt;mu nu au aua, ¶rt; aua a u ¶rt; mummuauma. aum mmuu mm m au (33), (34), (39), ¶rt;aum m mm au (46), (47), (49).

     

On the expanding earth hypothesis

Summary The hypothesis of an expanding Earth is discussed on the basis of lunar laser ranging It is provcd that the given data do not indicate a secular increase in the principal moment of the Earth's inertia which would have to occur if the Earth were really expanding.

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¶rt;amunma au u mu u ammuu a¶rt;u u ¶rt;a n a auu . aam, m n mu ¶rt;a m umamu amaua ma uuu u, m ¶rt; nmmam auu, u n¶rt; u m.

     

Travel time curves for complex inhomogeneous slightly anisotropic media

Summary The linearization approach is used to compute the travel times in inhomogeneous slightly anisotropic media. The basic formulae are outlined and their accuracy demonstrated in comparison with the exact solution based on the zero-order ray theory and the Backus formula (1965). The linearization is extended also to complex media with curved interfaces. The computer program for calculating travel times in 2D, inhomogeneous, slightly anisotropic, complex media is briefly described. The numerical results obtained for a realistic situation and various types of waves are presented to enable the effects of anisotropy and the effects of inhomogeneity on the resulting travel times to be compared.

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na uauua n¶rt;¶rt; ¶rt; ama¶rt;aa , anmau aaumn ¶rt;a. ¶rt; u n¶rt; au m u n muu nuuuu u m¶rt; aa (1965). a uauua n¶rt;¶rt; ¶rt; a ¶rt; uuuauau a¶rt;a. am nuaa uuma naa ¶rt; ama¶rt;a ¶rt; ¶rt;. u mam ¶rt; a mun ¶rt;am m um m aumnuu u m ¶rt;¶rt;mu a a anmau .

     

Magma in forearcs: implication for ophiolite generation

Forearc areas (“non-volcanic” arcs) of contemporary island arcs at convergent plate boundaries contain magmatic rocks. Geological evidence, seismic profiles, heat flow data, density considerations and petrological and geochemical arguments suggest that a forearc tholeiitic association (FAT) (containing high-Mg calc-alkaline andesites) is present in “non-volcanic” arcs at some stage of island-arc development. The fractionated, as well as primitive magma, is unable to penetrate low-density sediments and underplates thick piles of unconsolidated accreting rocks. The underplating causes upwelling. The occurrence of magma in forearcs provides an alternative interpretation for the tectonic setting of some ophiolitic masses. Rather than “ocean-ridge formation” and later “obduction” it offers an autochthonous (island-arc bound and geologically-substantiated) interpretation for the ophiolite suite.     

Hercynian-thrust related shear zones and deformation of the Varied Group on the contact of granulites/Southern Moldanubian,Bohemian Massif/

The three deformation phases inferred from the detailed structural analysis of the Cesky Krumlov Varied Group record the Hercynian development of the Southern Moldanubian of the Bohemian Massif. The deformation is related to the NW-SE thrusting of the large crustal units including granulites. The formation of the NS and NW-SE trending shear zones is connected with the thrust movement. The structural development begins with F₁ isoclinal fold formation, that could originate in unmetamorphosed sediments. In the final stage, they were strongly flattened and B₁ boudinage developed in the rocks. Aplite dykes and migmatitization of paragneisses occurred at the same time the rocks were metamorphosed. The D₂ deformational phase was produced by the simple shear deformation of the unit and folds of various styles around rigid inclusions and the strike-slip shear zone near the boundary of the granulite and the Varied Group were formed. The F₁ and F₂ folds are parallel with the stretching and mineral lineation indicating a NS to NW-SE direction of the thrusting. The youngest deformation is characterized by spectacular boudinage and by folding of the vertically oriented planes.

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Zusammenfassung Drei Deformationsphasen der variszischen tektonischen Entwicklung sind in der Bunten Gruppe des südlichen Moldanubikums des Böhmischen Massivs enthalten. Die Deformation ist mit der von NW nach SE orientierten überschiebung von gro\en Krusteneinheiten mit Granuliten verbunden. Die Entstehung von jüngeren N-S und NW-SE verlaufenden Scherzonen kann auf die überschiebungsbewegung bezogen werden. Die Strukturentwicklung beginnt mit F₁ isoklinalen Falten, die wahrscheinlich den nichtmetamorphisierten Sedimenten aufgeprägt wurden. Während der Abschlu\phase der Formung wurden sie stark geplättet und es entstand die B₁ Boudinage. Die Aplitgänge, Migmatitisation der Paragneisse und Metamorphose der Gesteine sind gleichzeitig. Die D₂ Deformationsphase wurde durch einfache Scherung der Einheit hervorgerufen und es entstanden Falten verschiedenen tektonischen Stils in der Umgebung starrer Einschlüsse und die Blattverschiebung an der Grenze von Granulit und Bunter Gruppe. Die F₁ und F₂ Falten liegen parallel zur Streckungslmeation und überschiebungsrichtung ab. Die jüngste Deformation ist charakterisiert durch eine spektakuläre Boudinage und Faltung der senkrecht stehenden Flächen.

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Résumé L'étude structurale détaillée de la Série Variée du Moldanubien méridional dans le Massif de Bohème a permis de distinguer trois phases de déformation dans le développement tectonique varisque. Cette déformation est liée au charriage, du Nord-Ouest vers le Sud-Est, de grandes unités crustales comportant des granulites. La genèse de zones de cisaillement plus jeunes, d'orientation N-S et NW-SE peut Être liée au mÊme processus de charriage. Le développement structural commence avec des plis isoclinaux F₁ engendrés vraisemblablement dans les sédiments non métamorphisés. Au stade final de leur formation, ils ont été très aplatis et un boudinage B₁ est apparu. L'intrusion de filons d'aplite et la migmatitisation des paragneisses sont contemporaines du métamorphisme. La deuxième déformation D₂ a été le fait d'un cisaillement simple; à ce moment se sont formés des plis de style tectonique très variés, localisés fréquemment autour d'inclusions rigides. De cette étape date également le décrochement ductile entre les granulites et la Série Variée. Les plis F₁ et F₂ sont parallèles à la linéation d'étirement (linéation minérale) qui indique la direction N-S à NW-SE du charriage. La déformation la plus jeune comporte un boudinage spectaculaire et le plissement des plans d'attitude verticale.

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- , : , . , ( ) ( ). - 502±10 , 0,71174±73. , . 471±9 0,70684±25, , , . - 56±1 . 120–230 , . 37±1 , , . 10,4 14,6, 8,9 11,8. , , , , — .

     

Some possibilities of predicting radio wave absorption in the lower ionosphere

Summary An attempt is made to show possible ways of predicting radio wave absorption in the midlatitude lower ionosphere using relations between absorption and the intensity of solar ionizing radiation and/or common solar activity indices, and between absorption and f₀F2.

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aa mu nuau nu a¶rt;u ¶rt;um u u a mu ¶rt; nu u umum uuu uu (uu uu u¶rt;au amumu) u ¶rt; nu u f₀F2.