Tidal evolution of the earth-sun system

Summary The tidal decrease in the Earth's heliocentric longitude generated by the Sun has been computed. It represents the increase in the length of year10^–7 s per century. The resonant angular velocity of the Earth's rotation is approximately equal to the present Earth's mean motion, however, for the model used, i.e., considering the Sun as the point-mass.

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u u zumu ¶rt;m u, a nuuau m a. ¶rt; mmmm uu ¶rt;u z¶rt;a10^–7 a mmu. a za m au u nu aa ¶rt; ¶rt;uu u, u, ¶rt;a, umam ¶rt;a ¶rt;u m a.

     

Local spatial nets derived from measurements of angles

Summary Some of the properties are discussed of local nets derived from measurements of angles by forward intersection. Their functionals and stochastic model indicate the way the effect of the initial data, of the model of determining refraction conditions can be taken into account, and the possibility of gradually obtaining the individual estimates of the coordinates of the points being determined.

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u¶rt; m ma a m, nm a auu nmam n au. a ua u mamu ¶rt;u mu m naam uu u¶rt; ¶rt;a, uu u n¶rt;u mua auu u m nmnz, m¶rt;z auau ¶rt;uam n¶rt; nm.

     

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.

     

On the calculation of the gravity terrain corrections in Czechoslovakia

Summary A calculation of the gravity terrain corrections by computer is proposed.

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¶rt;aam m¶rt; uuu mnauu nna unau uuum muu.

     

Lamellar pyroxenes and their petrogenetic significance: Three examples from the Czech Massif

The first event in the crystallization of pyroxenite in nodules from Bory was the growth of clinopyroxene at an uncertain 1,190(30)° C and 2.5(2)GPa. Lamellae of garnet and orthopyroxene in CPX nucleated slightly above 1,000° C and equilibrated at 940(20)° C and 3.9(6)GPa. The growth of lamellae was followed by crystallization of groundmass that corroded lamellar clinopyroxene. Phenocrysts of clinopyroxene and orthopyroxene in olivine pyroxenite from T?i Studně crystallized at 1,290(100)° C and 2.3(1.4)GPa. The lamellae in both phases nucleated between 1,400 and 1,200° C and equilibrated at 860(40)° C and 0.2(3)GPa, before regional metamorphism. (The temperatures of nucleation mentioned rest on uncertain assumptions in the phase-boundary theory and should be viewed with caution.) The serpentinized peridotite-pyroxenite from De?tná contains clinopyroxene relics (the only primary phase) with lamellae of a 1.42 nm sheet silicate topotactically pseudomorphing enstatite, possibly a chlorite or vermiculite. All phases in lamellae are crystallographically oriented in the hosts. The present cases suggest that when applying the theory of phase boundaries, a modified procedure of Robinson et al. should also be considered, in which identity of adjacent areas, rather than just vectors, is the basis of calculation. Spinel lamellae in CPX are bounded not only by faces parallel to coherent interfaces, but also by faces formed by accumulation of incoherent edges of growth ledges.     

Regularization of downward heat flow continuation

Summary Some regularization approaches to downward heat flow continuation from the Earth's surface to the depth of interest are presented, provided the heat transfer is described by the homogeneous steady-state equation. The Fourier transform of horizontal coordinates is used and the relation between the regularization of the heat flow spectrum and the regularization of the heat flow in the spatial domain are discussed. The utilization of an a priori information about the subsurface heat flow is mentioned.

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¶rt; m zuau n¶rt;¶rt; n¶rt;u u nmz mnz nma n¶rt;nuu, m n mna nuam ¶rt;¶rt; maua au (au anaa). na naau zuma ¶rt;uam u ama ¶rt; zuau mnz nma u uau z nma. nma m nuu anu u n¶rt;nmz mnz nma.

     

The use of the discrete surface fourier analysis of anomalous fields for resolving them

Summary The subject of this paper is one method of numerical computing of the resolution of a summary anomalous field into its components, a method which respects the spectral approach to this problem.Dedicated to 90th Birthday of Professor Frantiek Fiala     

Specific problems of ore prospection geophysics in regions of arid climate

Summary The present communication deals with problems that are common to the application of some geophysical methods in arid regions. Typical examples of using geothermic methods, D.C. and A.C. electrical and radiometric methods in the Eastern Desert of Egypt are presented. The conclusions were derived from a great number of measurements and are all associated with the physical properties of rocks on or near the surface under desert conditions.     

Eine Eichmethode für die Askania Erdgezeiten-Registrieranlage mit dem Galvanometer

Summary The scale-value switch (Fig. 1) makes it possible to calibrate even the older Askania tidal equipment with a galvanometer at a reduced scale-value. If resistors R ₂ and R ₃ are selected as shown in Eqs(4) and(5), the ratio of reduction of the scale value1/n does not depend on the internal resistance of the photo-cell in the gravimeter. The resistance of the recording galvanometer R ₄ must be determined with an accuracy of±1% in order to obtained an accuracy of±0.5%. Together with the reduction in scale value also the damping is considerably decreased, which enables the time, required for calibration, to be cut down considerably.