The effect of the galvanometer coupling on the accuracy of measuring the seismometer constants of an electromagnetic seismograph     

Vladimír Tobyáš  Reviewer J. Buben 《Studia Geophysica et Geodaetica》1980,24(4):382-388

Summary The errors in determining the partial constants of a seismometer using the method of recording the free oscillations of the seismometer by a galvanometer are analysed and the maximum values of the coupling coefficients at which the derived seismometer constants do not differ from the partial by more than 1%, are computed.  相似文献   

Vibration experiments with sharpe gravimeters     

Géza Csapó  Reviewer M. Pick  Reviewer V. Tobyáš 《Studia Geophysica et Geodaetica》1974,18(4):386-389

Summary The results of gravimeter measurements are influenced by various external effects among them by natural and artificial vibration sources. The nature of this disturbing factor is not yet clear, but to study phenomena is very important. In this paper the author reports on his vibration experiments carried out with a geodetic-type Sharpe gravimeter in a laboratory. The experiments confirm the existence of a vibration interval which is very dangerous for gravimeter observations.  相似文献   

The effect of the coupling between galvanometers on the characteristics of the Gs-11 gravimeter     

Vladimír Tobyáš  Reviewer L. Skalský 《Studia Geophysica et Geodaetica》1974,18(4):394-404

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The application of a finite difference model of internal tide generation to the NW European Shelf     

Dr. Toby Sherwin  Nicholas Taylor 《Ocean Dynamics》1989,42(3-6):151-167

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Near and Mid-Infrared Polarization of the Nucleus in NGC 1068     

Stuart Lumsden  Joss Bland-Hawthorn  Toby Moore  Craig Smith  Tak Fujiyoshi  Martin Ward 《Astrophysics and Space Science》1997,248(1-2):287-293

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A simple three-dimensional model of the earth's crust     

Karel Holub  Vít Kárník  Vladimír Tobyáš 《Studia Geophysica et Geodaetica》1966,10(3):370-375

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Broad-band electromagnetic seismographs with maximum sensitivity     

Vladimír Tobyáš 《Studia Geophysica et Geodaetica》1967,11(1):34-47

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Radio‐echo layering in West Antarctica: a spreadsheet dataset     

Martin J. Siegert  Magdeline Pokar  Julian A. Dowdeswell  Toby Benham 《地球表面变化过程与地形》2005,30(12):1583-1591

Of the various information recovered from radio‐echo sounding (RES) of polar ice sheets, internal layering is currently under‐utilized by glaciologists, due in part to a lack of available data. Here, RES layering of the West Antarctic Ice Sheet, from the 1970s RES survey of approximately 70 per cent of this ice mass, is made available in a series of spreadsheets. Three types of internal layers are evident in the dataset. The first is continuous layers that have a stratigraphic appearance and can often be traced easily for hundreds of kilometres. The second is buckled layering, which also resembles stratigraphy and can sometimes be traced over tens of kilometres (although layer identification can often be difficult). The roughness of these layers is often greater than the bed at the same wavelength. The third is highly distorted or absent layering, which is not possible to trace laterally. Despite debate concerning the origin of RES layers, they are thought by most glaciologists to represent isochronous surfaces. The pattern of internal layering is potentially of importance to glaciologists for three reasons. (1) The position of undeformed layers below the ice surface is a function of accumulation rate, ice flow and basal melting conditions. Numerical modelling (including new ‘data assimilation’ techniques) could be used to discriminate between these processes, so revealing important information about the ice sheet and its environment. (2) Buckled layers are deformed by ice flow process, and so their occurrence can be related to the flow dynamics of the ice sheet. (3) Very buckled layers are often associated with ice stream flow, which allows their location to mark the positions of past and present fast‐flowing ice. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Recognition of extraneous argon components through incremental-release ${}^{40}\text{Ar}{}^{39}\text{Ar}$ analysis of biotite and hornblende across the Grenvillian metamorphic gradient in southwestern Labrador     

R.D. Dallmeyer  Toby Rivers 《Geochimica et cosmochimica acta》1983,47(3):413-428

${}^{40}\text{Ar}{}^{39}\text{Ar}$ incremental-release ages have been determined for 15 hornblende and 20 biotite concentrates separated from rocks collected across the garnet and kyanite zones of Grenvillian metamorphism in southwestern Labrador. Most hornblende spectra from the kyanite zone are slightly discordant, with low-temperature increments yielding ages older than the ca 1000 Ma date suggested for culmination of Grenvillian metamorphism in the area. However, all the hornblende concentrates record well-defined plateau ages. These range from 968 to 905 Ma across the kyanite zone and date times of diachronous post-metamorphic cooling. The discordant spectra are interpreted to result from low-temperature liberation of excess ⁴⁰Ar components from grain margins. Two hornblende concentrates from the garnet zone display very discordant spectra (total-gas ages of 2100 and 3017 Ma) in which incremental dates systematically decrease during analysis. This pattern of discordance suggests that excess argon components are inhomogeneously distributed throughout these hornblende grains.Most biotites from the garnet and kyanite zones record total-gas or plateau ages in excess of 1000 Ma (2066-857 Ma), reflecting the widespread presence of excess argon components. Because most of the ${}^{40}\text{Ar}{}^{39}\text{Ar}$ age spectra are internally concordant, the ratios of excess ⁴⁰Ar relative to radiogenic ⁴⁰Ar must have been uniform in the various gas fractions liberated from each sample. This is also reflected in the inability of isotope correlation diagrams to differentiate between excess, radiogenic, and atmospheric argon components. The biotite total-gas or plateau dates show marked local variation. This is interpreted to indicate that the biotite grains were in contact with a post-metamorphic intergranular vapor phase that was characterized by large and variable ${}^{40}\text{Ar}{}^{36}\text{Ar}$ ratios. Such ratios most likely resulted from widespread diffusion of the argon liberated from adjacent Archean basement gneisses during the Grenvillian metamorphic overprint.  相似文献   

Partial derivatives of dispersion curves for higher modes of love waves in a single-layered medium     

Oldřich Novotný  Reviewer V. Tobyáš 《Studia Geophysica et Geodaetica》1972,16(1):51-59

Summary The partial derivatives of the dispersion curves have been calculated by means of a method founded on the theorem of implicit functions, which was described in[1]. The partial derivatives of the dispersion curves of Love waves are studied in detail for a model of a single-layered medium. Analytical formulae for the partial derivatives are used for deriving the limits of these partial derivatives when the period approaches zero or the critical period.  相似文献