A contribution to the fluctuations in climate in San José (Costa Rica)     

Karel Pejml 《Studia Geophysica et Geodaetica》1966,10(1):87-100

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Some mechanical analogies of magnetodynamic oscillations in a homogeneous medium     

Karel Prikner 《Studia Geophysica et Geodaetica》1970,14(3):339-344

Zusammenfassung Es wird auf die Analogien hingewiesen zwischen dem einfachsten Fall der Resonanz einer ebenen MD-Welle im Modell homogener Schicht der Erdmagnetosph?re und horizontaler Schwingung einer homogenen elastischen S?ule mit einem befestigten Ende. Es wird qualitativ die Analogie zwischen dem Anprall eines materiellen K?rpers an eine elastische S?ule mit einem befestigten Ende und dem Stoss der Front von Sonnenwind auf die Erdmagnetosph?re angedeutet. Diese Ann?herung erm?glicht die Illustration einiger Züge von Pulsationen, welche pl?tzliche Ver?nderungen in magnetischem Felde der Erde (Impulse si, ssc u. ?.) begleiten und deren Beschreibung auf Grund pr?ziser Theorie der Verbreitung von MD-Wellen sehr schwierig ist.

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Address: Boční II, Praha 4-Spořilov.  相似文献   

Combined tectonic-sediment supply-driven cycles in a Lower Carboniferous deep-marine foreland basin,Moravice Formation,Czech Republic     

Ond?ej?BábekEmail author  Radek?Mikulá?  Jan?Zapletal  Tomá??Lehotsky 《International Journal of Earth Sciences》2004,93(2):241-261

The Lower Carboniferous Moravian–Silesian Culm Basin (MSCB) represents the easternmost part of the Rhenohercynian system of collision-related, deep-water foreland basins (Culm facies). The Upper Viséan Moravice Formation (MF) of the MSCB shows a distinct cyclic stratigraphic arrangement. Two major asymmetric megacycles bounded by basal sequence boundary, each about 500 to 900 m thick, have been revealed. The megacycles start with 50- to 250-m-thick, basal segments of erosive channels: overbank successions and slope apron deposits interpreted as lowstand turbidite systems. Up-section they pass into hundred metre-thick, fine-grained, low-efficiency turbidite systems. Palaeocurrent data show two prominent directions, basin axis-parallel, SSW–NNE directions, which are abundant in the whole MF, and basin axis-perpendicular to oblique, W–E to NW–SE directions, which tend to be confined to the basal parts of the megacycles or channel-lobe transition systems in their upper parts. Based on the facies characteristics, palaeocurrent data, sandstone composition data and trace-fossil distribution data, we suggest a combined tectonics–sediment supply-driven model for the MF basin fill. Periods of increased tectonic activity resulted in slope oversteepening probably combined with increased rate of lateral W–E sediment supply into the basin, producing the basal sequence boundary and the subsequent lowstand turbidite systems. During subsequent periods of tectonic quiescence, the system was filled mainly from a distant southern point source, producing the thick, low efficiency turbidite systems. Consistently with the previous models, our own sediment composition data indicate a progressively increasing sediment input from high-grade metamorphic and magmatic sources up-section, most probably related to an uplift in the source area and progressive unroofing of its structurally deeper crustal parts. The first occurrence of the Cruziana–Nereites ichnofacies in sand-rich turbidite systems in the youngest parts of the MF (Goel to Gospi Zone), supported by rapidly increasing quartz concentrations in sandstones, is thought to indicate a transition from generally underfilled to generally overfilled phase in evolution of the MSCB basin. This transition may be linked to the onset of Upper Viséan phase of northward basin-fill progradation assumed by previous authors.  相似文献   

Mean Earth'S Equipotential Surface From Topex/Poseidon Altimetry     

Milan Burša  Jan Kouba  Karel Raděj  Scott A. True  Viliam Vatrt  Marie Vojtíšková 《Studia Geophysica et Geodaetica》1998,42(4):459-466

The geopotential value of W ₀ = (62 636 855.611 ± 0.008) m ² s ^–2 which specifies the equipotential surface fitting the mean ocean surface best, was obtained from four years (1993 - 1996) of TOPEX/POSEIDON altimeter data (AVISO, 1995). The altimeter calibration error limits the actual accuracy of W ₀ to about (0.2 - 0.5) m ² s ^–2 (2 - 5) cm. The same accuracy limits also apply to the corresponding semimajor axis of the mean Earth's level ellipsoid a = 6 378 136.72 m (mean tide system), a = 6 378 136.62 m (zero tide system), a = 6 378 136.59 m (tide-free). The variations in the yearly mean values of the geopotential did not exceed ±0.025 m ² s ^–2 (±2.5 mm).  相似文献   

Changes in the reflectivity of the midlatitude ionosphere with respect to the ULF (Pc1) signal     

Karel Prikner  Vladimír Vagner  Reviewer M. Hvoždara 《Studia Geophysica et Geodaetica》1988,32(1):84-100

Summary The method of numerical modelling of ionospheric filtration of the Fourier components of a signal from the frequency range of Pc1 micropulsations is employed in the spectral analysis (frequency f, angle of incidence ) of the relative characteristic of the amplitude and energy reflectivity of the ionospheric layer with respect to ordinary Alfvén modes incident in the meridional plane. The results are presented for four different models characterizing the midlatitude day- and night-time ionosphere under low and high solar activity. The results indicate the specificity of filtration of ordinary Alfvén waves. It is proved that the lower region of the modelled ionosphere, as part of the midlatitude ionospheric wave guide (in particular the F2 layer), behaves like an Alfvén resonator in the given spectral range.

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m¶rt; u ¶rt;uau u umauu -mau uaa u amm ¶rt;uanaa unau 1 n¶rtum nma aau (amma f, a¶rt;u ) mum anum¶rt; u mu maamu u ¶rt; ¶rt; a, a¶rt;au a u u¶rt;ua nmu. mam n¶rt;aam ¶rt; m a ¶rt; ¶rt;um m ¶rt; u u nu u u nu amumu. aam nuum umauu a. naa, m ua am ¶rt;ua u (a am F2-u ¶rt;um ¶rt;a) ¶rt;m nma ¶rt;uana a am a.

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Single- and inter-station transfer functions for non-synchronous geomagnetic arrays-II. the results of the field data analysis     

Karel Pěč  Jana Pěčová  Oldřich Praus  Reviewer M. Hvoždara 《Studia Geophysica et Geodaetica》1988,32(4):368-391

Summary The theory of methods of computing single- and inter-station transfer functions in both the spectral and time domains was developed in paper[1]. Both approaches are applied to the variation data recorded at field stations along two non-simultaneous profiles traversing the eastern margin of the Bohemian Massif, where a zone of anomalous induction seems to mark an important geological boundary of formations with different histories of development. The results of both analyses are found to coincide within reasonable bounds of 20–30% in the principal induction characteristics.

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u m¶rt; ama ¶rt;-u -mau n¶rt;am u nma u am a ua am[1]. am nua m am a n¶rt;¶rt;a nu ¶rt; aaua ¶rt;aaum auau aumua a n mau ¶rt; u nu, nau m au aua,¶rt; aa a aa u¶rt;uu. a, u¶rt;u, mamau a¶rt;a ¶rt; ¶rt; ¶rt;uuau au umuu aumu. mam aau nma u am auam a 20–30% ¶rt; u¶rt;u naam.

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Explanation of the internal air pressure effect on the worden gravity meter dial constant     

Karel Diviš  Vladimír Tobyáš  Bohumil Chán  Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1989,33(2):206-209

Summary A model, explaining the effect of air pressure changes in the space of the measuring system on the fine dial counter constant of the Worden and similar gravity meters, is presented. It is based on the changes of the bellows volume with compensating the gravity changes. It is shown that the resetting the gravity meter in the whole range has practically no influence on the fine dial counter constant.

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u¶rt;a ¶rt;, na m uu ¶rt;au ¶rt;a nmam uum um a nm a umaauma ¶rt; u nuaum. ¶rt; aa a uu a ua umu uma nu nauu uu u mmu. aa, m nma ¶rt;uanaa um namuu um a uu nm a uma.

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Normal density earth models   总被引：1，自引：0，他引：1  

Zedeněk Martinec  Karel Pěč  Reviewer M. Burša 《Studia Geophysica et Geodaetica》1986,30(2):124-147

Summary Models of the Earth's density, close to thePREM model, have been derived, they reproduce the external normal gravitational field of the Earth and its dynamic flattening, and are referred to as normal density models. The Earth's surface is approximated by an ellipsoid of the order of the flattening, or of its square. Of the group of normal models sgtisfying the solution of the inverse problem, the normal density modelHME2 is recommended. The spherically symmetric density modelPREM, which was corrected in the course of solving the inverse problem, thus creating the modifiedPREM-E2 model, was used as the a priori information.

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¶rt; ¶rt;u an¶rt;u nmmu uu ¶rt;uPREM (m. a. a ¶rt;u nmmu), aumau n m u¶rt;mu na¶rt;am auaumau n u. m u annuum am unu¶rt; au. uau amu a ¶rt; mam H==0.003 273 994. ma ¶rt; a ¶rt; ¶rt;m ¶rt;HME2. am anu u a ¶rt; nmmu a unaa ¶rt; a¶rt;ua umua ¶rt;PREM. ¶rt;aam ¶rt;uuau m ¶rt;u n¶rt; aauPREM-E2.

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Peculiarities of electron precipitation in morning sector of auroral zone during geomagnetic storm     

Yu. V. Gotselyuk  M. S. Kazaryan  S. N. Kuznetsov  Karel Kudela  Ivan Kimák  Reviewer S. Fischer 《Studia Geophysica et Geodaetica》1986,30(1):79-86

Summary The analysis of electron (E _e >30keV) and proton (E _p >150keV) precipitating fluxes measured on low altitude satellite Intercosmos-17 during the geomagnetic storm December 2, 1977 is presented. Particularly, the gap in electron precipitation on morning side at L=5÷6 is analyzed and discussed in terms of strong cyclotron diffusion.  相似文献   

Matrix approach to the solution of free toroidal elastic oscillations of the earth     

Zdeněk Martinec  Karel Pěč  Reviewer Z. Martinů 《Studia Geophysica et Geodaetica》1985,29(2):163-168

Summary The propagator matrix is expressed in terms of cross-products of spherical Bessel functions and their derivatives. A fast computational algorithm is suggested. The matrix form of the variational principle with the boundary term is derived.

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u nu u u u, n¶rt; u¶rt; nu¶rt;u uu u u u nuo¶rt;. ¶rt; au u . ¶rt; u uau nuuna u .

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