The prehistory of clay mineralogy is highlighted from the beginnings in ancient Greece to the mineralogical works of Agricola, in particular his famous handbook of mineralogy, entitled De natura fossilium (1546). Starting with a few scattered hints in the works of Archaic and Classic Greek authors, including Aristotle, the first treatment of clays as a part of mineralogy is by Theophrastus. This basic tradition was further supplemented by Roman agricultural writers (Cato, Columella), Hellenistic authors (the ge ographer Strabo and the physicians Diosco rides and Galen), the Roman engineer-architect Vitruvius, and finally summarized in Pliny’s encyclopedia Naturalis historia, which has become the main source for later authors, including Agricola. It is shown to what extent Agricola’s work is just a great summary of this traditional knowledge and to what extent Agricola’s work must be considered as original. In pa rticular, Agricola’s attempt to a rational, combinatorical classification of "earths" is recalled, and aplausible explanation is given for his effort to include additional information on Central European clay depos its and argillaceous raw material occurre nces. However, it is shown that - in contrast to common belief - Agricola was not the first to include "earths" in a mineralogical system. This had been done almost one thousand years earlier by Isidore of Seville., Willi Pabst and Renata Kořánová., and Obsahuje bibliografické odkazy
Thirty years long measurements of plumb line variations carried on with help of horizontal pendulums provided us information of non-tidal effects. Installation of the long water tube tiltmeter opens for us new possibility to answer the question, which part of non-tidal effects observed by means of pendulums was associated with geodynamic phenomena and which part was of instrumental or local origin. Two years long measurements of the long water-tube tiltmeter showed us some important similarities between non-tidal effects registered by both instruments: comparable amplitudes of non-tidal effects, time of durations of non-tidal effects as well as irregularity of occurring of non-tid al events. In spite of disjunction of time series of measurements obtained with help of horizontal pendulums and long water-tube tiltmeters we are able to conclude that the reasons of large non-tidal effects can not be simply explained by influence of temperature or pressure variations., Marek Kaczorowski., and Obsahuje bibliografické odkazy
Among the first GPS geodynamics projects in Czech Republic the MORAVA network was founded in 1994 with aim to determine the positional changes at border zone between the Bohemian Massif and the Carpathians. Initial project included three successive GPS campaigns in period 1994 - 1996, but was not continued because of lack of support. It had been possible to carry out new measurements in southern part of the MORAVA network including five stations, after gap of 15 years. In the paper comparison of previous and contemporary results of epoch GPS measurements are presented, which indicate block movement tendencies at the Bohemian Massif and the Western Carpathians border, thus confirming activity of the area up to present days., Otakar Švábenský, Michal Witiska, Jan Ratiborský, Radim Blažek, Lubomil Pospíšil and Josef Weigel., and Obsahuje bibliografii
The permanent GPS stations are particulary important for studying various phenomena because they provide uninterrupted measurements allowing to form the time series of station coordinates. Analysis of GPS solutions time series (GPSSTS) for short meridian baselines were explored in the paper (Kryński and Zanimonskiy, 2000). In our article we intend to extend the analysis of the GPSSTS for baselines of different lengths and azimuths. GPS observation data from the ASG-PL network have been used in the research. The GPSSTS in time and frequecy domain have been analyzed. The spectrums of the GPSSTS with the using coherence function were compared. Moreover, a practical approach to correct any unmodeled effects in GPS baseline solutions that cannot be computed using classical GPS adjustment was presented., Władysław Góral and Daniel Jasiurkowski., and Obsahuje bibliografii
The WEST SUDETEN geodynamic network consists of 11 sites on that five annual GPS epoch measurements in period of 2001-2005 were carried out. The 48-hour epoch data linked to 4 permanent EPN station observations created reasonable GPS data base for a preliminary evaluation of site movement velocities. General movement pattern over the network has been obtained and some regional and local movement relations among network sites were observed and discussed. The whole region under study displays three areas with relatively different movement trends. The northern area, i.e. the Krkonoše Mts. structural block, displays pronounce motion to the NW with respect to the central area that involves the Permian piedmont of the Krkonoše Mts. covered in its southern part by the Cretaceous sediments. Besides, conspicuous dextral movement along the Železné hory Mts. fault zone was detected too., Vladimír Schenk, Zdeňka Schenková, Milada Grácová and Pavel Kottnauer., and Obsahuje bibliografii
The fault displacement monitoring network EU-TecNet was established to define microdisplacements across faults in the territory of Central Europe (www.tecnet.cz) using three-dimensional optical-mechanical extensometers. The results of long-term neotectonic activity obtained from two caves localized in the eastern part of the Slovenský kras Mts. (SE Slovakia) show generally NE-SW oriented dilatation. This orientation is in a good accordance with the orogen-parallel extension monitored in the Western Carpathians. Differing short-lasting trends were distinguished in 2011-2012 and 2013-2015, which supports the significance of the tectonic pulse at the end of 2012 and the beginning of 2013. Moreover, simultaneous short-lasting faulting occurred at both sites under the transtensional tectonic regime, where the principal maximum compressional axis operated in a NW-SE direction (σ1). The observed results were compared to data from monitoring points in distant areas of the European plate. and Briestenský Miloš, Hochmuth Zdenko, Littva Juraj, Hók Jozef, Dobrovič Roman, Stemberk Josef, Petro Ľubomír, Bella Pavel.
Underground mining hard coal in the area of Walbrzych ended in the late 90-ties of the last Century. Its effects on the state of heterogeneous rock mass (complicated geology and tectonics) is still evident and not known precisely. Analysis of levelling measurement results carried out after the end of mining activity (1997-2008) for part of the former “Thorez” mine indicates increased rock mass surface activity in tectonic zones. With the aim to continue monitoring of the rock mass surface movements on the area of former mining grounds a research satellite GPS network (7 points) has been established and supplemented with new precise levelling lines linked to the existing 2nd class levelling network. Location of these points takes into consideration, among other things geology and tectonics of the Walbrzych Basin and areas of underground mining activity. In this paper work on the design and construction of the research satellite GPS and levelling networks has been described and the first measurement campaign carried out in September 2009 has been presented. Its results will form foundation for complex studies of rock mass surface in the next measurement epochs., Jan Blachowski, Wojciech Milczarek and Stefan Cacoń., and Obsahuje bibliografii
The periodic motion of the Earth's spin axis in space (nutation) is dominantly forced by external torques exerted by the Moon, Sun and planets. On the other hand, long-periodic geophysical forces (with periods longer than several days), mostly caused by the changes in the atmosphere and oceans, have dominant effects in polar motion (in terrestrial frame) and Earth's speed of rotation. However, even relatively small short-periodic (near-diurnal) motions of the atmosphere and oceans can also have a non-negligible influence on nutation, thanks to the resonance that is due to the existence of a flattened outer fluid core. The retrograde period, corresponding to this resonance, is roughly equal to 430 days in non-rotating quasi-inertial celestial reference frame, or 23h 53min (mean solar time) in the terrestrial frame rota ting with the Earth. The aim of the present study is to use the geophysical excitations in the vicinity of this resonance to estimate their influence on nutation, based on recent models of atmospheric and oceanic motions. To this end, we use the numerical integration of Brzezinski's broad-band Liouville equations and compare the results with VLBI observa tions. Our study shows that the atmospheric plus oceanic effects (both matter and motion terms) are capable of exciting free core nutation; both its amplitude and phase are compatible with the observed motion. Annual and semi-annual geophysical contributions of nutation are of the order of 100 microarcseconds. They are slightly different for different at mospheric/oceanic models used, and they also differ from the values observed by VLBI - the differences exceed several times their formal uncertainties., Jan Vondrák and Cyril Ron., and Obsahuje bibliografické odkazy
In the paper a problem of elaboration and the use local quasige oid on mining areas in south-eastern Poland is discussed. The models were elaborated within research projects carried by Institution of Geodesy and Cartography AGH in years 1996-2005 and related to mining caused terrain surface deformation problems. One part of the carried research was elaboration of quasi-geoid model that can be used in practical aspects of mine surveying. There is an example of this quasi-geoid model application in leveling surveys presented in the paper. Furthermore, discussed quasi-geoid models elaborated for small areas provide detailed information about the shape of this surface and they determine database completing existing country models as for example Leveling Geoid 2001 for area of Poland., Piotr Banasik., and Obsahuje bibliografické odkazy
This paper presents an analysis of trends and causes of changes of selected hydroclimatic variables influencing the runoff regime in the upper Hron River basin (Slovakia). Different methods for identifying trends in data series are evaluated and include: simple mass curve analysis, linear regression, frequency analysis of flood events, use of the Indicators of Hydrological Alteration software, and the Mann-Kendall test. Analyses are performed for data from two periods (1931-2010 and 1961-2010). The changes in runoff are significant, especially in terms of lower QMax and 75 percentile values. This fact is also confirmed by the lower frequency and extremity of flood events. The 1980s are considered a turning point in the development of all hydroclimatic variables. The Mann-Kendall test shows a significant decrease in runoff in the winter period. The main causes of runoff decline are: the considerable increase in air temperature, the decrease in snow cover depth and changes in seasonal distribution of precipitation amounts., Andrea Blahušiaková, Milada Matoušková., and Obsahuje bibliografické odkazy