Regional VS30 model for the St. Lawrence Lowlands,Eastern Canada     

Miroslav Nastev  Michel Parent  Nicolas Benoit  Martin Ross  Danielle Howlett 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2016,10(3):200-212

Shear-wave velocity of the top 30?m, V_S30, is commonly used for prediction of the seismic site response. This paper presents development, validation and uncertainty assessment of a regional V_S30 model based on a combination of simplified 3D geology and statistically representative velocity values. Results identify soft marine sediments in deep sedimentary basins as zones most susceptible to seismic shaking. Compared to the available urban-scale seismic zonation studies, the regional model showed a success rate of roughly 64% in predicting local site category. The standard deviation was in average 30% of the expected V_S30 value.  相似文献   

Ten years of Czechoslovak research in numerical weather prediction     

Stanislav Brandejs  Miroslav Škoda  Vojtěch Vítek  Otakar Zikmunda 《Studia Geophysica et Geodaetica》1963,7(3):308-311

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Some minerals as new natural models of ferrites     

Václav Hanus  Miroslav Krs 《Pure and Applied Geophysics》1965,60(1):129-136

Summary The electron density distribution in the intermediateE-F layer is determined by developing theN(z) profile into a power series. The unknown coefficients are found by means of the boundary conditions for transition towards theE andF1 layers as well as by the value of the maximum electron density in the intermediate layer. In case that stratiform layers in theE-F layer which can be sounded are not available, the measured value for the nondeviative absorption at short waves reflected by theF layer is made use of. The comparisons show the reliable accuracy of the method when seven terms are used in the power series.  相似文献   

Is radiomagnetization possible?     

Miroslav Krs 《Studia Geophysica et Geodaetica》1967,11(4):464-465

Резюме Дискутирована возможность, возникаетли под влиянием действия γ-облучения и постоянного магнитного поля на ферромагнитные вещества новыИ вид намагниченности, т. н. радионамагниченность. Приведеннее рассуждение частично обосновано экспериментами выполненнычi БродскоИ, которая лабораторным образом проверила некоторые изменения магнитных свойств минералов под влиянием γ-облучения. Остается пока необБясненным вопрос, если специфичные магнитные свойства верхнепалеозойских горных пород не были обусловлены интенсивным (или долговременным) воздействием γ-облучения при совместном воздействии геомагнитного поля.   相似文献   

Magnetism and ferromagnetism of natural minerals of the spinel group     

Vladimír Kropáček  Miroslav Krs 《Studia Geophysica et Geodaetica》1968,12(4):385-397

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Climate Change Impacts and Adaptation Strategies in Spring Barley Production in the Czech Republic   总被引：1，自引：0，他引：1  

Miroslav Trnka  Martin Dubrovský  Zdeněk Žalud 《Climatic change》2004,64(1-2):227-255

The crop model CERES-Barley was used to assess the impacts of increased concentration of atmospheric CO₂ on growth and development of the most important spring cereal in Central and Western Europe, i.e., spring barley, and to examine possible adaptation strategies. Three experimental regions were selected to compare the climate change impacts in various climatic and pedological conditions. The analysis was based on multi-year crop model simulations run with daily weather series obtained by stochastic weather generator and included two yield levels: stressed yields and potential yields. Four climate change scenarios based on global climate models and representing 2 × CO₂ climate were applied. Results: (i) The crop model is suitable for use in the given environment, e.g., the coefficient of determination between the simulated and experimental yields equals 0.88. (ii) The indirect effect related to changed weather conditions is mostly negative. Its magnitude ranges from ?19% to +5% for the four scenarios applied at the three regions. (iii) The magnitude of the direct effect of doubled CO₂ on the stressed yields for the three test sites is 35–55% in the present climate and 25–65% in the 2 × CO₂ climates. (iv) The stressed yields would increase in 2 × CO₂ conditions by 13–52% when both direct and indirect effects were considered. (v) The impacts of doubled CO₂ on potential yields are more uniform throughout the localities in comparison with the stressed yields. The magnitude of the indirect and direct effects ranges from ?1 to ?9% and from +31 to +33%, respectively. Superposition of both effects results in 19–30% increase of the potential yields. (vi) Application of the earlier planting date (up to 60 days) would result in 15–22% increase of the yields in 2 × CO₂ conditions. (vii) Use of a cultivar with longer vegetation duration would bring 1.5% yield increase per one extra day of the vegetation season. (viii) The initial water content in the soil water profile proved to be one of the key elements determining the spring barley yield. It causes the yields to increase by 54–101 kg.ha^?1 per 1% increase of the available soil water content on the sowing day.  相似文献   

The Western Carpathians—interaction of Hercynian and Alpine processes     

Miroslav Bielik  Jn &#x;efara  Michal Kov   Vladimír Bezk  Du&#x;an Pla&#x;ienka 《Tectonophysics》2004,393(1-4):63

The complicated structural and rheologic properties of Western Carpathian lithosphere reflect the complex geodynamic history of the Carpathian orogen. Based on critical analysis of earlier models, new interpolation of existing geophysical data and results of integrated modelling, a new map of the lithosphere thickness for the Carpathian–Pannonian region has been constructed. The map allows for the distinction of a frontal orogen collision zone in the NE (from increased lithosphere thickness) as well as a zone of oblique collision with the Bohemian Massif in the West, where lithosphere is not significantly thickened. The MOHO discontinuity beneath the Western Carpathian hinterland (Danube and East Slovak Basins), as defined by deep reflection seismic profiling, is relatively shallow. This probably reflects recent crustal extension related to oblique collision between the European plate and the ALCAPA block and an increase of the asthenospheric updoming from the Middle Miocene onward.Crustal thickness reflects the combined effects of deep-seated orogenic processes and mantle thermal evolution beneath the Pannonian Basin system. In this study, we focus particularly the structures of: (1) the Late Alpine collision and Neogene back arc basin development, including deep-seated contacts between colliding plates, a zone of slab detachment, the compressional accretionary wedge of the Outer Western Carpathian Flysch Belt, and extensional structures produced by subduction rollback and asthenosphere upwelling; (2) Early Alpine structures related to Cretaceous thrust-stacking, including subhorizontal reflection packages (interpreted as multi-generational extensional structures), the underplated intra-Penninic (Oravic) continental ribbon, and ophiolite traces of the Meliatic oceanic suture; and (3) north-dipping reflectors interpreted as remnant Hercynian lithotectonic fragments with opposed vergency to the subducted Alpine units.  相似文献   

Accuracy of integral migration transformation in dependence on space-time sampling     

Miroslav Novotný  Review: A. Zátopek 《Studia Geophysica et Geodaetica》1985,29(3):248-256

Summary The accuracy of wave field extrapolation is studied with respect to the discretization of field data and integral extrapolator. Assuming a far-field approximation of the Rayleigh-Sommerfeld solution for a two-dimensional scalar wave equation, the minimum and the maximum transmitted frequency are expressed as functions of the sampling intervals t, x, and the half-width x₀ and angle _a of the migration aperture. The theoretical limitation of the transmitted frequency band is tested on numerical examples.

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An Outburst Detected in the Spectrum of Hd 6226     

Miroslav Šlechta  Petr Škoda 《Astrophysics and Space Science》2005,296(1-4):179-182

HD 6226 is a bright binary Be star at visual magnitude 6.81 (Hipparcos database). The emission and absorption phases occur in cycles, which are probably not periodic. The suspected period of about 630 days (derived from photometric measurements) is not confirmed by our spectroscopic survey. The latest emission phase developed in the beginning of 2003, then the emission strength systematically decreased and disappeared between July 21, 2003 and August 4, 2003. The last (absorption) spectrum was exposed on August 25, 2003. Unexpected very strong emission appeared in a spectrum exposed on October 28, 2003. A short-term photometric brightening followed this “outburst”. Long-term spectroscopic RV studies revealed a 2.615 d period modulated by a 29.7 d period (in the He I 6678 line), which perhaps may be interpreted as orbital period of a binary. Nevertheless, the physical nature of the dominant short 2.615 d period is not yet clear. The last detected emission episode has changed considerably our view of the interesting object HD 6226. We hope this study will reveal more details of the physical properties of the Be phenomenon.  相似文献   

A hypothetical end of creative-expansive evolution phase of the expansive non-decelerative universe     

Vladimír Skalský  Miroslav Súkeník 《Astrophysics and Space Science》1992,191(2):333-339

The hypothetical final parameters of the Universe result from the model properties of the expansive non-decelerative universe and properties of the hypothetical primordial black holes.  相似文献