The essential point for seismological observation in the northern part of Moravia, Czech Republic, is a permanent seismic station Ostrava - Krásné Pole (OKC) that is a part of the Czech regional seismological network (hereafter CRSN). Institute o f Geonics AS CR, v.v.i., has also operated temporary seismic stations in this region since 1997. Current seismological stations are located in an abandoned mine working located in Zlaté Hory and in cellars in Klokočov and castle Raduň near Opava. The natural seismicity is after the swarm of microearthquakes in the vicinity of Opava in 1993 very low now. In region under discussion, seismic manifestations generated by mining induced seismicity in Upper Silesian Coal Basin (both Karviná an d Polish parts) and in Legnica-Głogów Copper District (LGOM) are also detected. Significant part of observations in this region is made by the Institute of Physics of the Earth (hereafter IPE), Masaryk University Brno, and about 1000 microearthquakes have been detected during the last ten years with maximum local magnitude up to 1.9., Zdeněk Kaláb, Jaromír Knejzlík and Karel Holub., and Obsahuje bibliografické odkazy
The article deals with estimating deformation between the African and the Eurasian Plate in the Eastern Mediterranean on the basis of GPS coordinate time series. Two sources of velocities were used for processing. The first was the freely available site velocities from the European Permanent Network (EPN). The second was the Egyptian GPS permanent network velocities. Their values were determined by the following technique. Firstly, the Egyptian site coordinates were computed from GPS daily observations, using the fiducial EPN stations. The daily site coordinates at a given time interval result in coordinate time series, which were analysed and used on velocity estimation of the Egyptian stations. Then the apparatus of the mechanics of continuum was applied to all resultant velocities. The regions of possible mutual interactions between the Eurasian and the African Plate in the Eastern Mediterranean were detected. The basic idea of this contribution is the common processing of GPS daily measurements from the Egyptian permanent network together with the EPN data. The available Egyptian GPS data cover almost the last three years, which represents a sufficient time interval for velocity estimation. Introducing the Egyptian permanent GPS measurements into processing enables a better estimate of deformations in the Eastern Mediterranean., Antonín Zeman, Khalil Hassan, Jan Holešovský, Abdel Monem S. Mohamed, Zbyněk Novotný, Mahmoud M. Salah, Jan Kostelecký and Radwan M. Ali., and Obsahuje bibliografii
Brown coal open pit mining in the basin under Krušné Hory Mts. came to contact with slopes of the mountains, and a problem of the stability in high and steep slopes in the crystalline rock became an important question. The question concerns Jezeří Castle built on the top of one of the hills in a most endangered section where even a supporting pillar in the sediments under the slope toe was left to support the slope. As a result, an extensive monitoring program regarding deformations was initiated in the region. The program involved several methods and some important results are discussed. The results that are displayed concern mainly measurements done in geophysical tiltmeter stations in two underground galleries driven into the two steep slope sections showing most dangerous situation, as well as extensometers located in the same locations. Long-term monitoring revealed a tectonic deformation process of a natural origin that is registered as slow and systematic tilts. Besides, it revealed several periods of anomalies that are of basic importance. During a long period of observation from 1982 till 2005 three important deformation anomalies were registered: the event of 1994, the event of 2002, and the event of 2003/2004. The first and the third event have been classified as of a large regional character that affected a wide mountainous area and could be interpreted as a tectonic impulse originating within the mountainous structure of the so called "Dome of Hora Svaté Kateřiny". The second event has been considered different, strictly connected with extreme precipitation of August 2002. The anomaly was evidenced even deep in the crystalline, so that it could not be seen as of a superficial character only. The movement which was registered at that time was oriented right into the pillar supporting the slope., It is concluded that it was a short manifestation of instability in the critical profile "Jezeří - pillar", which stresses the important stabilisation function of the supporting pillar without which the profile will be probably destabilised., Blahoslav Košťák, Bohumil Chán and Jan Rybář., and Obsahuje bibliografii
a2_The town of Litija was hit by four damaging earthquakes in the last 120 years which reached a maximum intensity of VII-VIII MSK. The town is located in a shallow sedimentary basin filled with relatively soft Quaternary sediments in which seismic site amplification is expected. On the other hand no borehole or geophysical data are available to support quantitative assessment of site effects. As a contribution to the first seismic microzonation of the area, we performed a free-field study based on the microtremor HVSR method in order to assess the resonance frequency of th e sediments. In ge neral clear spectral peaks were obtained for 57 measuring points which show distribution of frequencies in a broad range between 4.4 an d 22.7 Hz. The iso-frequency map was prepared by using natural neighbour interpolation algorithm. For soil-structure resonance assessment we considered large building stock from different Slovenian towns, because the building typology is similar in wider area. Low-rise masonry family houses with two or three floors prev ail. By microtremor measurements inside 45 such buildings their fundamental longitudinal and transver se frequencies were determined and statistically analysed in a complementary study. To assess the possible occurrence of soil-structure resonance in general, the average fundamental frequency +/- one standard devia tion interval is obtained for these two building heights, which give s the range 5.6-11.1 Hz. The free-field microtremor data shows that this frequency range occupies 37% of the urban area in the Litija basin. This study has shown that soil-structure resonance issue for low-rise buildings is frequently overlooked, but should be considere d seriously in shallow sedimentary basins, characterized by relatively high free-field frequencies, because many towns are located in such geological environment., a2_Second application of the derived iso-frequency map is to support soil classification, because recent investigations have shown that fundamental frequency of sediments can be used together with the average shear velocity in the upper 30 m to improve classi fications according to di fferent seismic codes., Andrej Gosar., and Obsahuje bibliografické odkazy
The article deals with geodynamical phenomena of marginal parts of sandstone plateaus. The area of interest consists of several partial areas in the Bohemian Paradise natural reserve. These areas rise above terrain as relics of a once uniform sandstone plateau. The current relief developed mainly in the Pleistocene, when the Jizera River carved present day wide valley and the underlying soft clay rocks were uncovered. Thus favorable conditions were created for slow destruction of sandstone plateaus. Here, the slope movements occur up to the present days in the form of landsliding and slow block movements and their epiphenomena. Due to this continuing activity of the slope movements, human settlements and cultural monuments are endangered. Research in this area helps us to clarify the relation between slope movements and other factors, such as the presence of a significant tectonic failure in the vicinity or the influence of the water regime., Ingrid Forczek., and Obsahuje bibliografii
This paper describes limestone body situated in the northern part of the Branná group near Vápenná village in Javorník area. The body is confined by two major tectonic zones of this area - Sudetic Marginal Fault on the east and Ramzová overthrust on the south. Detailed tectonic analysis has been performed in two big limestone quarries named quarry I and II. Strikes and dips of fault planes and joints were measured. In the quarry I just one important orientation of the fault planes was found - WE mostly vertical. In the quarry II two main fault plane orientations were observed - vertical NW-SE Sudetic and NE-SW Moravo-Silesian. The senses of movements in the fault planes were determined using the calcite steps mainly as the kinematic indicators. Presence of the kinematic indicators allowed performing of paleostress analysis. Several different tectonic phases were identified and discussed., Lucie Nováková., and Obsahuje bibliografii
We have surveyed the Earth's surface using gravity anomalies and second-order radial derivatives of the disturbing gravitational potential computed from the gravitational model EGM2008 complete to degree and order 2159 (for selected degrees up to 2190). It corresponds to 5 arcmin resolution on the ground. Over most well known impact crater sites on the Earth we found the second-order derivatives (not available from ordinary gravity surveys) offered finer discrimination of circular features than the gravity anomalies themselves. We also discovered that some of the sites show evidence of double or multiple craters which will need further ground verification. Some of these signatures (in hilly or mountainous terrain) may also need to be corrected for the gravitational effect of topography to sharpen their hidden features., Jaroslav Klokočník, Jan Kostelecký, Pavel Novák and Carl A. Wagner., and Obsahuje bibliografii
This paper presents results from the exam ination of flood embankments by means of three geophysical methods: GPR, mutual impedance of loop antennas measurements and D.C. resistivity method. In order to increase measuring accuracy, the mutual impedance measuring system works at a high frequency. Parameters of mutual impedance measuring system were presented. A method of mutual im pedance measurement results was described. Flood embankments examination results showed that the simultaneous use of few geophysical methods increases accuracy of inhomogeneities detection in near-surface structure of the ground., Remigiusz Mydlikowski, Grzegorz Beziuk and Adam Szynkiewicz., and Obsahuje bibliografické odkazy
The objective of this work is the chemometric quantification of minerals in rocks. A chemometric method was developed for the determination of chlorite, muscovite, albite and quartz in claystones and clay shales using infrared spectroscopy. Bromide pellets and diffuse reflectance were used to measure the infrared spectra; principa l component analysis and partial least-squares regression were used as chemometric methods. Spectral regions (4000-3000 cm-1 and 1300-400 cm-1) containing important spectral information were chosen by principal compone nt analysis. The calibration models were created by a partial least-squares regression. The mean relative error and relative standard deviation were calculated for the assessment of accuracy and reproducibility. The value of the mean relative error was about 10 % for most of the calibration models. The value of the relative standard deviation ranged from 1.1 to 3.0 % for most calibration models based on diffuse reflectance spectra and from 4.0 to 9.2 % for most calibration models based on spectra obtained with bromide pellets., Michal Ritz, Lenka Vaculíková, Eva Plevová, Dalibor Matýsek and Jiří Mališ., and Obsahuje bibliografické odkazy
It is the objective of this thesis to take into account thermal balance of circulating fluidised bed combustors (CFBC), aiming at efficiency assessment, as regards standards, CSN 07 0302, and DIN 1942. It points to differences between calculations along these two different standards, concerning the solution of problems like different comparative temperatures, to which the calculation of physical losses is related to, varying calculation of mean thermal capacity, or problem of electrical motors input. This article is based on the project GA 617 50 11 solving - "Combine combustion of coal and biomass in fluid boilers"., Zdeněk Kadlec, Bohumir Čech and Jan Matoušek., and Obsahuje bibliografii