High-resolution magnetostratigraphy and micropalaeontology across the J/K boundary strata at Brodno near ilina, western Slovakia: summary of results     

Vclav Hou a  Miroslav Krs  Marta Krsov  Otakar Man  Petr Pruner  Daniela Venhodov 《Cretaceous Research》1999,20(6):699

This study summarizes the final results of magnetostratigraphic and micropalaeontological investigations of the Tithonian/Berriasian boundary (J/K) limestones at the locality of Brodno near ilina, Western Carpathians, West Slovakia. The aim is to prepare the background for correlation of a Late Tithonian and Early Berriasian biostratigraphic zonation with global magnetoevents (manifested in detailed magnetostratigraphic profiles) between the Tethyan realm and other regions, particularly the Boreal and Pacific realms. Suitable physical properties of the limestones studied, a favourable geological setting and rich microfossil assemblages (calpionellids) at Brodno (magnetozones M21r to M18r) allowed a systematic collection of new data on the original synoptic section, which now has the character of a high-resolution profile across the J/K boundary. Two reverse subzones detected within magnetozones M20n and M19n are named ‘Kysuca Subzone’ and ‘Brodno Subzone’, respectively. Both can be correlated with analogous subzones in the M-sequence of marine anomalies. Their existence can also be confirmed in the Bosso Valley section in Umbria, central Italy. A detailed study of the interval between magnetozones M20n and M17r in the Bosso Valley profile is presently in its final stage. Both magnetostratigraphic profiles, from the Brodno and Bosso Valley localities, were thoroughly investigated in the intervals close to the J/K boundary and are still unique among continent-based profiles in the detection and precise definition of both reverse subzones within M20n and M19n. Samples collected from the boundary strata of the reverse Kysuca Subzone at Brodno indicated a transition from N (R) to R (N) polarity of the Earth's palaeomagnetic field within a time interval of c. ±5 ka. Limestone samples (total number N=368) were subjected to progressive thermal demagnetization in 10–12 thermal fields and to subsequent multi-component analysis of remanence. The C-component, as the carrier of palaeomagnetic directions, was determined in the temperature interval of 300° to 540°, or possibly 580°C. Magnetomineralogical analyses of pilot samples and unblocking temperatures determined for all samples showed that magnetite is the carrier of remanent magnetization. The positions of the individual events of calpionellid stratigraphy relative to the global magnetic polarity timescale are precisely defined. The base of the Calpionella Standard Zone, which is considered a provisional J/K boundary indicator in ammonite-free sections in the Tethyan realm, lies within magnetozone M19n at the level of 35% of its local thickness. None of the boundaries in the calpionellid zonation coincides precisely with any of those in the palaeomagnetic zonation, but the first appearance ofCalpionella grandalpina , indicating the base of the Intermedia Subzone, lies in close proximity to the base of magnetozone M19r.  相似文献   

Year‐round estimation of soil moisture content using temporally variable soil hydraulic parameters          下载免费PDF全文

Vaclav Sipek  Miroslav Tesar 《水文研究》2017,31(6):1438-1452

Soil moisture plays a key role in the hydrological cycle as it controls the flux of water between soil, vegetation, and atmosphere. This study is focused on a year‐round estimation of soil moisture in a forested mountain area using the bucket model approach. For this purpose, three different soil moisture models are utilised. The procedure is based on splitting the whole year into two complement periods (dormant and vegetation). Model parameters are allowed to vary between the two periods and also from year to year in the calibration procedure. Consequently, two sets of average model parameters corresponding to dormant and vegetation seasons are proposed. The process of splitting is strongly supported by the experimental data, and it enables us to variate saturated hydraulic conductivity and pore‐size characterisation. The use of the two different parameter sets significantly enhances the simulation of two (Teuling and Troch model and soil water balance model‐green–ampt [SWBM‐GA]) out of three models in the 6‐year period from 2009 to 2014. For these two models, the overall Nash‐Sutcliffe coefficient increased from 0.64 to 0.79 and from 0.55 to 0.80. The third model (the Laio approach) proved to be insensitive to parameter changes due to its insufficient drainage prediction. The variability of the warm and cold parameter sets between particular years is more pronounced in the warm periods. The cold periods exhibited approximately similar character during all 6 years.  相似文献   

Model of the expansive nondecelerative universe     

Vladimír Skalský  Miroslav Súkeník 《Astrophysics and Space Science》1991,178(1):169-171

The joint article is concerned with derivation of equations of dynamics of the expansive nondecelerative universe and determination of its basic properties, relations, and parameters with the state equationp=–1/3.  相似文献   

Similarities of and differences between three mountain belts at the border of the pannonian basin due to the behaviour of the mohorovičić discontinuity     

Krešimir Čolić  Svetozar Petrović  Hans Sünkel  Miloslav Burda  Miroslav Bielik  Vincenc Vyskočil 《Studia Geophysica et Geodaetica》1994,38(2):131-139

Summary The Dinarides, the Eastern Alps and the Western Carpathians being situated at the borders of the Pannonian basin, are of very similar origin. Therefore, the results obtained in the investigation of correlations between Earth gravity field parameters (absolute geoid undulations, gravity anomalies), the surface topography and the shape of the Mohorovičić discontinuity, were compared. It was found that these three regions have the same basic characteristics, but also their own specific features. While the similarities follow clearly from these investigations, the found differences might partly be a consequence of non-uniformity and unmatched quality of data sets used for the three regions. A short version of this paper, entitled "Kindredness of three mountain belts at the border of the Pannonian basin — deduced from the behavior of the Mohorovičić discontinuity" was presented at the 7th International Symposium "Geodesy and Physics of the Earth", Potsdam, October 5–10, 1992 and published in the Proceedings. Presently a visiting professor at the Graz University of Technology, Institute for Theoretical Geodesy, Department for Physical Geodesy, Austria. Presently at the Berlin University of Technology, Germany, as an Alexander von Humboldt Foundation Research Fellow.  相似文献   

Graphic symbols and local identity: the case of use and perception of municipal emblems in the Liberec Region (Czechia)     

Miroslav Šifta 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2016,116(2):147-158

This paper analyses the role of graphic symbols in local representation and in the process of local identity formation. The extent of graphic symbols utilization by local development actors in the region, its importance for image formation of the locality (municipality) from the point of view of the local development actors and an assessment of the degree of identification with the municipal emblems among the local population are evaluated, based on the results of a corresponding survey targeted at municipal representatives. Municipal emblems tend to (and also should) have a local representative function. These should emphasize local specificity, uniqueness. Municipal emblems have a potential to play the role of connecting, mediating and activating factors also on a higher as well as a local level. Municipal emblems are still not used enough and in the right way by actors of municipality representations. These are often misunderstood and deemed unimportant for local development.  相似文献   

Rb-Sr isotopic composition of granites in the Western Krušné hory/Erzgebirge pluton,Central Europe: record of variations in source lithologies,mafic magma input and postmagmatic hydrothermal events     

David Dolejš  Jiří Bendl  Miroslav Štemprok 《Mineralogy and Petrology》2016,110(5):601-622

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Optical spectra of supernova remnant candidates in the Sculptor Group galaxy NGC 300     

William C. Millar  Graeme L. White  Miroslav D. Filipović  Jeffrey L. Payne  Evan J. Crawford  Thomas G. Pannuti  Wayne D. Staggs 《Astrophysics and Space Science》2011,332(2):221-239

We present moderate-resolution (<5 Å) long-slit optical spectra of 51 nebular objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting the criterion of [S?ii]_Total:Hα≥0.4 to confirm supernova remnants (SNRs) from optical spectra, we find that of 28 objects previously proposed as SNRs from optical observations, 22 meet this criterion with six showing [S?ii]_Total:Hα of less than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated with the 28 previously proposed SNRs. Of these four, three (included in the 22 above) meet the criterion. In all, 22 of the 51 nebular objects meet the [S ii]_Total:Hα criterion as SNRs while the nature of the remaining 29 objects remains undetermined by these observations.  相似文献   

Consequences of climate change for the soil climate in Central Europe and the central plains of the United States   总被引：2，自引：0，他引：2  

Miroslav Trnka  Kurt Christian Kersebaum  Josef Eitzinger  Michael Hayes  Petr Hlavinka  Mark Svoboda  Martin Dubrovský  Daniela Semerádová  Brian Wardlow  Eduard Pokorný  Martin Možný  Don Wilhite  Zdeněk Žalud 《Climatic change》2013,120(1-2):405-418

This study aims to evaluate soil climate quantitatively under present and projected climatic conditions across Central Europe (12.1°–18.9° E and 46.8°–51.1° N) and the U.S. Central Plains (90°–104° W and 37°–49° N), with a special focus on soil temperature, hydric regime, drought risk and potential productivity (assessed as a period suitable for crop growth). The analysis was completed for the baselines (1961–1990 for Europe and 1985–2005 for the U.S.) and time horizons of 2025, 2050 and 2100 based on the outputs of three global circulation models using two levels of climate sensitivity. The results indicate that the soil climate (soil temperature and hydric soil regimes) will change dramatically in both regions, with significant consequences for soil genesis. However, the predicted changes of the pathways are very uncertain because of the range of future climate systems predicted by climate models. Nevertheless, our findings suggest that the risk of unfavourable dry years will increase, resulting in greater risk of soil erosion and lower productivity. The projected increase in the variability of dry and wet events combined with the uncertainty (particularly in the U.S.) poses a challenge for selecting the most appropriate adaptation strategies and for setting adequate policies. The results also suggest that the soil resources are likely be under increased pressure from changes in climate.  相似文献   

Supermassive black hole growth and merger rates from cosmological N-body simulations     

Miroslav Micic  Kelly Holley-Bockelmann  Steinn Sigurdsson  Tom Abel 《Monthly notices of the Royal Astronomical Society》2007,380(4):1533-1540

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Depth-Recursive Tomography of the Bohemian Massif at the CEL09 Transect—Part A: Resolution Estimates and Deblurring Aspects     

Miroslav Novotný 《Surveys in Geophysics》2011,32(6):827-855

The refraction CEL09 profile from the CELEBRATION 2000 project intersects the main terranes of the Bohemian Massif in the NW–SE direction: the Saxothuringian, the Teplá-Barrandian, the Moldanubian and the Moravo-Silesian. In its easternmost part, it crosses the Western Outer Carpathians overthrust westward onto the Bohemian Massif. Only the first 450 km were surveyed with the densest deployment of shot points providing data suitable for a reliable geological interpretation. The first-arrival depth-recursive tomography was applied here to derive a P-wave velocity image of the upper and middle crust (Part A). The proper interpretation of the obtained velocity features is the subject of the accompanying paper (Part B). The attained resolution in the velocity image is shown to be superior as compared with the previous CEL09 models based also on the more uncertain later arrivals of reflection waves. The applied DRTG (depth-recursive tomography on grid) method is based on a regular network of refraction grid rays generated for iteratively updated starting models. Only the distinct first arrivals with minimum uncertainty are used for the DRTG inversions to yield the maximum resolution. Thanks to the full control of the data fit by the grid rays used, the statistical lateral resolution could be determined at single grid depths for the chosen confidence levels. Thus, the lateral sizes of the anomalies that can be yet resolved are determined in dependence on their depths and their velocity excesses. The defocusing of the imaged features is studied on the basis of the spatial responses to spike excitation. The calculated spatial responses also allowed the edge smearing of the velocity anomalies to be assessed. Special attention is paid to the imaging of low-velocity zones that are usually suppressed by the smoothing measures used in standard tomographic methods. An improvement was achieved if the smoothing was suggested with regard to the occurrence of the low-velocity zones repeatedly appearing in higher iterations. The gained deblurring effect concerns both the negative and positive anomalies as documented on the velocity features interpreted in the accompanying paper.  相似文献