Showing papers in "Studia Geophysica Et Geodaetica in 1973"
TL;DR: In this article, the classical transformer bridge has been supplemented with an auxiliary compensating arm for balancing the bridge without any mechanical infringement of the measuring coils, achieving a sensitivity of 4 × 10 −8 SI units (3 × 10−9 e.m.u/cm3).
Abstract: A bridge set for measuring the magnetic susceptibility of rocks and its anisotropy is described. The classical transformer bridge has been supplemented with an auxiliary compensating arm for balancing the bridge without any mechanical infringement of the measuring coils. By employing this principle and the appropriate methods a sensitivityof 4 × 10 −8 SI units (3 × 10 −9 e.m.u./cm3) has been achieved for a sample of 8 cm3 in volume. In addition to its high sensitivity the device has a considerable accuracy, which makes it suitable for susceptibility anisotropy measurements even of samples with a very low susceptibility and only slight anisotropy. Well-reproducible results have been achieved for samples with a mean susceptibility of the order of10 −5 SI units with an anisotropy degree of only about 1.05.
129 citations
TL;DR: In this paper, the authors propose a method to solve the problem of the lack of a sufficient number of translational data points for a given task by using the information of the current state of the art.
Abstract: Иссле¶rt;уеmся оnре¶rt;еленuе уnру
uх nосmоянных nо скоросmям объемных волн. Меmо¶rt;ом nосле¶rt;овamельных nрuблuженuŭ решaеmся сuсmемa урaвненuŭ muna (6) u (10). Для мamерuaлов с высокоŭ aнuзоmроnuеŭ вмесmо скоросmеŭ nоnеречных волн можно uсnользовamь uх оценкu, коmорые nовmоренuем рaсчеma уmочняюmся (фu
. 2). Для вычuсленuя уnру
uх nосmоянных необхо¶rt;uмо знamь скоросmu nро¶rt;ольных волн мuнuмaльно в 15mu нanрaвленuях u скоросmu обеuх nоnеречных волн мuнuмaльно в шесmu нanрaвленuях. Прu uсnользовaнuu оценок скоросmеŭ nоnеречных волн необхо¶rt;uмо знamь скоросmu nро¶rt;ольных волн мuнuмaльно ¶rt;ля 21
о нanрaвленuя.
21 citations
TL;DR: In this paper, the results of DSS measurements along international profile VII, carried out by Czechoslovak and Polish geophysicists in 1970-71, are dealt with, and mean velocities are computed from the travel-time curves of the reflected waves (PM and PK) and the refracted waves (Pg).
Abstract: The paper deals with the results of DSS measurements along international profile VII, carried out by Czechoslovak and Polish geophysicists in 1970 – 71. The profile situation is shown in Fig. 1. By 1971 part of the profile in the region of the Bohemian Massif between points 1 and 3 and in Poland between points 5 and 7 had been surveyed (Fig. 2). The seismograms were used to construct the travel-time curves of the fundamental types of waves PK, PM, Pn (Fig. 4). The mean velocities were computed from the travel-time curves of the reflected waves (PM and PK) and the refracted waves (Pg). Isolines of the mean velocities could be constructed for the region of the Bohemian Massif (Fig. 6). The velocity data found were used for the depth interpretation of the travel-time curves of the principal types of waves and to construct a seismic section (Fig. 8). In the region of the Pre-Sudeten block the thickness of the crust was found to be 34–37 km, and in the Sudeten it increased to 40 km. Towards the south the thickness of the crust gradually reduces to 30 km in the system of the Lužice faults. In the Bohemian Cretaceous the thickness of the crust is about 30 km. Further to the south, in the region of the Moldanubicum, the thickness of the Earth's crust increases rapidly, and at the southern border of the Central Bohemian pluton it reaches values of about 42 km.
14 citations
TL;DR: In this paper, the Earth's rotational deformation was considered, and the gravity observations were used to estimate the Love numbers h2 and k2 at the Chandler frequency for polar motion correction.
Abstract: When correcting precise gravity measurements for polar motion, the Earth's rotational deformation must be considered, as this will increase the correction based on a rigid Earth by about 15%. Conversely the gravity observations can be used to estimate the Love numbers h2 and k2 at the Chandler frequency.
12 citations
TL;DR: In this paper, the potential energy of the Earth-Moon system was derived and the disturbing potential function responsible for the lunar precession of Earth's axis, with preserving the terms from the non-spherical disturbing body.
Abstract: The potential energy of the Earth—Moon system is derived and, thus, also the disturbing potential function, responsible for the lunar precession of the Earth's axis, with preserving the terms from the non-spherical disturbing body. The gravitational fields of the Earth and Moon are considered in the form of a development in terms of spherical harmonics upto n=4.
11 citations
TL;DR: In this article, the results of an analysis of investigations into continental Quaternary sediments, which have become the object of close palaeomagnetic studies in Czechoslovakia in recent years, are presented.
Abstract: Apart from a brief account of the theories of the geomagnetic field and from suggestions of obtaining new data, the present work contains an analysis of the results of investigations into continental Quaternary sediments, which have become the object of close palaeomagnetic studies in Czechoslovakia in recent years. Besides sea sediments they represent one of the few possibilities of obtaining more complete data on the past of the geomagnetic field even though their investigation requires instruments of high sensitivity and exact processing technique. A brief geological description and chronological list of individual sedimentary cycles are presented and the results of their palaeomagnetic investigation on a number of samples (about 2 000) are given. The obtained results suggest that the geomagnetic field probably displayed successive changes in the position of its magnetic axis shifting from the region of the south pole to the region of the north pole over a period of approximately 2.5 millions of years in the form of oscillations caused by impulses recurring at periods of about 140 000 years. Three types of changes of the geomagnetic field with different periods can be identified (Fig. 2): not always expressive changes with the period of 2.5 × 10
4
years, quasisinusoidal changes with a period of about 1.4 × 10
5
years and long-term changes most likely also periodical with the period of about 2.5 × 10
6
years. The first and the second periods, particularly, are close to the precession constants as far as the magnitude is concerned. Thus it can be stated that the differences in the precession rates of the motion of the core and the mantle may markedly act together in the origin of the geomagnetic field.
8 citations
TL;DR: In this article, a brief geological asessment of the sedimentational cycles, analyses the methods of collection and investigation of samples and the representativeness of the results obtained, and problems of magnetic cleaning and the types of demagnetization curves investigated are discussed.
Abstract: The paper brings a brief geological asessment of the sedimentational cycles, analyses the methods of collection and investigation of samples and the representativeness of the results obtained. Problems of magnetic cleaning and the types of demagnetization curves investigated are discussed. The continuous nature of the variations of the magnetic declination, inclination and remanent magnetization, determined by palaeomagnetic investigation of Quaternary sediments, is also discussed. The conclusion contains the principal facts about the dynamics of the geomagnetic field in the Quaternary and points out the possibility of applying them to the theory of the geomagnetic field, as well as to geological correlations.
8 citations
TL;DR: It has been shown that it is necessary to combine several methods to be able to describe and explain recent movements of the Earth's crust as discussed by the authors, and it has been proved that combining several methods is necessary and sufficient to explain the recent movements.
Abstract: It has been shown that it is necessary to combine several methods to be able to describe and explain recent movements of the Earth's crust.
8 citations
TL;DR: In this article, the main geological and geophysical applications of magnetic susceptibility anisotropy are briefly described and some conclusions concerning its significance are deduced, and all accessible data were used.
Abstract: In the first part of this paper, the main geological and geophysical applications of magnetic susceptibility anisotropy are briefly described. In the second part, the data on the magnetic anisotropy of various rock types are summarized and some conclusions concerning its significance are deduced. For this purpose, all accessible data were used.
7 citations
TL;DR: In this article, the X and Y components of data from the Budkov Observatory were used to study the daily variations of the fundamental characteristics of the pulsations, the frequency f0 and amplitude A0 of the main spectral peaks.
Abstract: The spectra of nearly 100 samples of Bpc3 pulsations were computed in the X and Y components of data from the Budkov Observatory. These spectra were used to study the daily variations of the fundamental characteristics of the pulsations, the frequency f0 and amplitude A0 of the main spectral peaks. The daily variation of the ellipticity of the polarization ellipses of oscillations in frequency f0 was also studied in the XY-plane.
6 citations
TL;DR: In this article, a series of about 100 samples of geomagnetic beating-type pulsations pc3 was treated statistically and the quantitative data obtained on the internal structure of the pulsations (frequency spectra and polarization characteristics) were treated.
Abstract: Using the method of two-component spectral analysis of planar oscillation events by means of computer processing of A-t records, a series of about 100 samples of geomagnetic beating-type pulsations pc3 was treated. The quantitative data obtained on the internal structure of the pulsations (frequency spectra and polarization characteristics) were treated statistically. The pattern of the daily variations of the frequencies and amplitudes of the fundamental amplitude-dominating frequency components of the pulsations and the daily variations of the polarization characteristics of these components, the ellipticity of the polarization ellipses, the directions of the main axes of these ellipses and the sense of rotation of the disturbance vector along the ellipses were obtained.
TL;DR: The Interkosmos5 VLF experiment consisted of a spectrum analyser with twelve narrowband channels and broadband measurements between 0.07 and 20 kHz using an analogue telemetry with a tape recorder on board.
Abstract: The Interkosmos5 VLF experiment consisted of a spectrum analyser with twelve narrow-band channels and broadband measurements between0.07 and20 kHz using an analogue telemetry with a tape recorder on board. The apparatus used in the experiment is shortly described, some examples ofVLF phenomena observed are given and a review of all analogue data recorded is shown in a graphical calendar.
TL;DR: In this article, the positions of the magnetic N pole were computed for the interval of transition from Matuyama's epoch of negative polarity to Brunhes epoch of positive polarity at time intervals of about 10, 000 years and that their was an apparent westward drift of the pole.
Abstract: As the result of the palaeomagnetic research into the loesses and soils of Quaternary age from the locality of Cervený Kopec (Czechoslovakia) it was found that the viscous remanent magnetism (RM) of these rocks exceeds the stable component of the RM. Figures 1–6 show polar graphs and the demagnetization curves corresponding to cases when the rocks sedimented in a magnetic field, the direction of which corresponded to the direction of the present geomagnetic field, or when the X and Z components of the field were of the opposite sense. The positions of the magnetic N pole were computed for the interval of transition from Matuyama's epoch of negative polarity to Brunhes's epoch of positive polarity. At the time of the reversal it was found that the pole moved along an oval at time intervals of about 10 000 years and that their was an apparent west-ward drift of the pole. The reversal found in the Quaternary is compared with the reversal in the Pliocene. The agreement in the pole movements in these two cases seems to indicate constant causes of these large changes in the magnetic field and a possible relation between the pole movement and the boundaries of the lithospheric blocks.
TL;DR: In this article, the Vorticity-Zentrums auf die Grenzflache zweier Luftmassen der mittleren geographischen Breiten studiert.
Abstract: Es wird der Einfluss des sogenannten Vorticity-Zentrums auf die Grenzflache zweier Luftmassen der mittleren geographischen Breiten studiert. Zwecks Aufklarung der Rolle des Bewegungs- und Druckfeldes in diesem Prozesse wurde ein einfaches Modell konstruiert und numerisch gelost. Die sich entwickelnde frontale Welle kann beziehungsweise als ein Anfangswert beim Losen der mit der Stabilitat der Wellen verbundenen Probleme mittels der Gleichungen, linearisiert durch die Methode der kleinen Storungen, dienen. Bei der Konstruktion des Modells wird ausser anderem von der Geometrie der Bewolkung ausgegangen, wie sie auf den Aufnahmen der meteorologischen Satelliten erfasst ist.
TL;DR: In this article, a two-component spectral analysis is proposed for the analysis of short-period geomagnetic pulsations, which is suitable for investigating a planar stationary oscillatory event.
Abstract: Summary: A new method is presented of computer processing of amplitude-time records. The method is based on a two-component spectral analysis, suitable for investigating a planar stationary oscillatory event. The method is applied to the study of the fine structure of short-period geomagnetic pulsations. Apart from a semi-quantitative representation of the directional distribution of the pulsation event in the plane of oscillation, the proposed method enables one to obtain quantitative information on the frequency components, representing the pulsation -- the distribution of the overall energy in the spectrum of the pulsation, the ellipticity of the polarization ellipses, the orientation of the major axes of the ellipses, and the sense of rotation of the disturbance vector. In studying the fine structure of the pulsations of the geomagnetic field it is usual to start with the analysis of the spectra of the records in two, or three perpendicular components of the field (X, Y, Z) separately [1, 2]. In these components only the projections of the pulsation event are studied. Their selection is related to the geometry of the magnetosphere and, thus, to the geometry of propagation of HM waves, however, it does not provide a sufficiently representative image of the spatial formation of the disturbance under any conditions. Only by processing the spectra simultaneously in all independent components can one obtain new information, e.g., the polarization characteristics (the ellipticity of the polarization ellipse of the oscillation, etc.) for the frequencies, corresponding to the main peaks in the spectra, in [3]. Processing by computer makes it possible to go into greater detail in treating the spectra. In the present paper the authors describe a new method of spectral analysis, suitable for investigating the planar stationary oscillatory event. Drawing on the spectra of a signal in two mutually perpendicular components, the spectrum of the projection into any chosen direction is computed. On applying this method concretely to the study of the fine structure of geomagnetic pulsations, one can obtain, in the first place, a spatial image of the frequency content of the pulsation (frequency-direction display). It is also possible to obtain a whole series of data on the polarization characteristics of the oscillation in frequencies, corresponding to selected spectral peaks (the frequency components of the pulsation).
TL;DR: In this paper, the spectral norm of the covariance matrix of the rigorously adjusted co-ordinates of a relatively large network is derived for the photogrammetric bundle block networks.
Abstract: A relatively large network is one which covers a large area whereas each observation only involves points within a small local area. For such networks an efficient method is described to establish the lower bounds for the spectral norm of the covariance matrix of the rigorously adjusted co-ordinates. The method utilizes a classification of observations and networks which is thought to be interesting in itself. The weakness of pure angular networks is revealed to stem from the fact that such networks offer little resistance to conformal distortions of the network. A numerical example is given. Asymptotic results for block-type networks are obtained which apply among others to photogrammetric bundle block networks.
TL;DR: In this paper, the dispersion equation is expressed by means of matrices, the elements of which are real or pure imaginary, and different matrices have been found, which have only real elements.
Abstract: In Haskell's formulation the dispersion equation is expressed by means of matrices, the elements of which are real or pure imaginary [2]. In the present paper different matrices have been found, which have only real elements.
TL;DR: In this paper, a review of the terms of functional analysis which can be exploited for statistical treatment of geophysical fields is given, and a procedure for determining the statistical characteristics of the fields, defined by a single realization, which does not require the limiting assumption of homogeneity to be introduced, is outlined.
Abstract: A review of the terms of functional analysis, which can be exploited for statistical treatment of geophysical fields, is given. The procedure for determining the statistical characteristics of the fields, defined by a single realization, which does not require the limiting assumption of homogeneity to be introduced, is outlined.
TL;DR: In this paper, the boundary condition for the gravity disturbing potential was derived upto the second-order terms and the influence of the secondorder terms was investigated, where the second order terms were derived from the first order terms.
Abstract: The boundary condition for the gravity disturbing potential was derived upto the second-order terms and the influence of the second-order terms was investigated.
TL;DR: In this paper, Stokes's constants were used to derive the Gaussian curvature of the external equipotential surfaces of the geopotential field of the Earth's surface.
Abstract: Stokes's constants J
n
(k)
and S
n
(k)
of the Earth's body, determined from satellite orbit dynamics[1] upto a comparatively high degree, give a unified description of the fundamental features of the geopotential field. In the present paper, which ties up with[4, 5], they were used to derive the Gaussian curvature of the external equipotential surfaces of the geopotential.
TL;DR: In this paper, a solution of the direct gravity problem for a finite body with variable density is given, based on Green's formula and applicable when a particular solution of Poisson's equation is known.
Abstract: A solution of the direct gravity problem for a finite body with variable density is given. The method is based on Green's formula and is applicable when a particular solution of Poisson's equation is known. The attraction due to the body is expressed by integrals over its surface
TL;DR: In this paper, the spectral approach is used for numerical computing of the resolution of summary anomalous fields into its components, a method which respects the spectral approaches to this problem, and is shown to be more accurate than the spectral spectral approach.
Abstract: 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.
TL;DR: In this paper, a method of colour schlieren recording of the compressional-stress field gradients, suitable for focal zone study on models, has been suggested, which gives instant quantitative information on these fields.
Abstract: A method of colour schlieren recording of the compressional-stress field gradients, suitable for focal zone study on models, is suggested. The study presents colour schlieren records of the compressional-stress fields in loaded square plates, containing inhomogeneities which give instant quantitative information on these fields. If the inhomogeneity is shaped like Griffith's diagonal slit, good agreement is demonstrated between the experiment and the theoretical calculation of the compressional-stress field in a model.
TL;DR: The magnitude station correction of the seismic station Kasperske Hory, related to Průhonice, was determined for the vertical component of short-period P waves as mentioned in this paper.
Abstract: The magnitude station correction of the seismic station Kasperske Hory, related to Průhonice, was determined for the vertical component of short-period P waves.
TL;DR: In this paper, the statistical properties of random fields are analyzed by analyzing their increments (i.e. the differences of values at two points) and the properties of structure functions are described and the possibility of testing the statistical homogeneity of geophysical fields and their possible homogeneization is discussed.
Abstract: Facts about the statistical properties of random fields may be obtained by analysing their increments (i.e. the differences of values at two points). The properties of structure functions are described and the possibility of testing the statistical homogeneity of geophysical fields and their possible homogeneization are discussed.
TL;DR: In this article, the authors discuss the importance of the use of the information of the user's interaction with the system, and the role of the interaction between the user and the system.
Abstract: Прuбо¶rt;яmся резуельmamы чuсленных рещенuŭ урaвненuя Гельм
ольцa в
орuзонmaльно нео¶rt;норо¶rt;ноŭ облaсmu с nросmым нaклонным конmaкmом ¶rt;врх сре¶rt; с рaзлuчнымu элекmрuческuмu nрово¶rt;uмосmямu в случaях Н- u Е-nолярuзaцuŭ. Анaлuзuрыжmся maкже мо¶rt;елu с нaклонным конmaкmом ¶rt;вух сре¶rt; зaле
aющuх нa
орuзонmaлвно о¶rt;норо¶rt;ном nрово¶rt;ящем слое ¶rt;ля Н-nолярuзaцuu. Иссле¶rt;уеmся nове¶rt;енuе nоверхносmных uмnе¶rt;aнсов u кaжсущuхся соnроmuвленuŭ u рaссмamрuвaжmся сооmвеmсmвужщuе uскaженuя мa
нumоmеллурuческuх крuвых зон¶rt;uровaнuя в рaзлuчных mочкaх в¶rt;олв nрофuля, nересекaюще
о нaклонныŭ конmaкm нa nоверхносmu Землu.
TL;DR: In this paper, the existence and uniqueness of a discrete, surface, optimum (in the Wiener sense) filter for filtering geophysical fields considering a spectral approach to the construction of the said filter is given.
Abstract: Proof is given of the existence and uniqueness of a discrete, surface, optimum (in the Wiener sense) filter for filtering geophysical fields considering a spectral approach to the construction of the said filter. It is also shown that the filtration coefficients and the filtration errors of the filter, constructed with the help of statistical estimates of the required spectral densities, converge towards their theoretical values. From the mathematical point of view, this paper concludes the building-up of the mathematical model of the discrete Wiener optimum surface filtration, suitable for geophysical fields.
TL;DR: In this article, the mean curvature of the equipotential surface and the vertical gradient of gravity are expressed in terms of a development into a series of spherical harmonics, neglecting terms of the order of 10−8.
Abstract: The mean curvature of the equipotential surface and the vertical gradient of gravity are expressed in terms of a development into a series of spherical harmonics [1, 2, 4], neglecting terms of the order of 10−8. The curvature anomalies have been computed using the satellite data [3]. The symbols used are the same as in [5].
TL;DR: In this paper, Schlieslich et al. untersuchen ein einfaches stochastisches Modell der in der Ubertragungs-Gleichung der Diffusion enthaltenen Korrelations-Funktion.
Abstract: Bei Studium der turbulenten Diffusion passiver Teilchen gehen wir aus statistischer Dynamik des Prozesses hervor, die auf dem zu einem unendlichen System von Gleichungen fuhrenden Formalismus der Verteilungsfunktionen beruht. Wir behandeln in Kurze das Problem der Abgeschlossenheit, das man sowohl fur die Turbulenz-Dynamik, als auch fur die turbulente Diffusion ubereinstimmend formulieren kann. Verschieden sind nur die Ausgangs-Bewegungsgleichungen. Wir studieren die statistische Struktur des entsprechenden Operators der Ubertragung (kinetisches Modell) und suchen den Zusammenhang zwischen dem Modell des Ubergangs zum Gleichgewichtszustand fur die grundlegende kinetische Gleichung und die Struktur des Ubergangs fur die Einteilchen-Dichte, Schlieslich untersuchen wir ein einfaches stochastisches Modell der in der Ubertragungs-Gleichung der Diffusion enthaltenen Korrelations-Funktion.