The paper presents the results of monitoring study undertaken during the period 2008 - 2010. The study recorded the displacement of tectonic structures in the Strašín Cave (SW Bohemian Massif). The derived results were compared, among others, with data recorded over the same time period across the Bohemian Massif in the EUTecNet (tectonic displacement monitoring net - see www.tecnet.cz), which is managed by IRSM ASCR. The rate of recorded displacement is mostly in order of hundredths mm/year with maximal value recorded in vertical component at site Strašín 2, about 0,16 mm/2,5 years. Whilst recorded displacement can indicate blocks subsidence into the cave empty space, the periods when displacement occurred correspond to periods of increased movement activity recorded for example at the opposite side of the Bohemian Massif, along the Sudetic Marginal Fault. Moreover, both periods are simultaneous with extraordinary earthquakes that affected western and southern part of the Bohemian Massif in 2008 and 2009., Josef Stemberk and Filip Hartvich., and Obsahuje bibliografii
Two seismic sources were tested on different surfaces during acquisition of a 5.5-km long high resolution seismic reflection (HRS) profile on the Ljubljana Moor in central Slovenia. Maximum target depth range of the survey was 200 - 300 m. Nine different combinations of source-surface conditions were analysed. Seismic sources included a seismic shotgun and an accelerated weight dropper system. The HRS profile crossed different surfaces including: paved roads, gravel roads, ploughed fields, grasslands and marshlands. Seismic source performance on different surfaces was evaluated through frequency and S/N ratio analyses of seismic data, and analysis of source-generated coherent noise appearance on seismograms. Results show that both seismic sources are suitable for some of the surfaces found in the surveyed area. The accelerated weight dropper produced the best results on gravel road surface, but poor results were found on grassland and ploughed fields. The seismic shotgun produced the best results in water-saturated soil on marshlands. It performed less favourably in unsaturated soil, generating more coherent noise. Water-saturated marshland surface and gravel road surfaces were found to be the most favourable for acquisition of high-resolution seismic reflection data on the Ljubljana Moor., Jure Atanackov and Andrej Gosar., and Obsahuje bibliografii
Parameters of finite seismic source model were determined for a set of 36 selected events of the West Bohemia 2000 earthquakes swarm (Ml from 1.7 to 3.0) using stopping phases method. Two stopping phases are generated along the source border where the rupture process terminates and these phases form Hilbert transform pair, which is also the criterion for their identification. Circular and e liptical source models were considered and corresponding source parameters were calculated by inverting interpreted stopping phases delays. As generalization of circular to elliptical model was found to be statistically insignificant, only results related to the circular source including error estimates are presented. Our results are in a good agreement with previously published theoretical formula concerning source radius and magnitude and also fairly well confirm general theoretical assumption about constant stress drop. The determined stress drop ranges between 1 - 10 MPa with the typical value of 2.4 MPa., Petr Kolář and Bohuslav Růžek., and Obsahuje bibliografické odkazy
The oldest mine cavities of the Jeroným Mine were already mined out more than 400 years ago. That is why it is necessary to determine the stability of individual parts of underground spaces. The assessment of stability of mine cavities is based on the long-term monitoring of chosen parameters. A distributed measurement network has been operated here using several different types of sensors. A laser distance meter that is used for measuring the height of a large chamber is one of these sensors. The results obtained from this monitoring are presented. Even if no apparent correlation seems to be visible between Earth’s tides and LDM variations, some features of recorded data, like dynamical frequency crossover in the power spectrum, could be due to the tidal cycles of the Earth., Zdeněk Kaláb, Markéta Lednická, Jaromír Knejzlík and Luciano Telesca., and Obsahuje bibliografii
Using of shaped conical borehole bottom to determination of the stress tensor changes induced by changing of geomechanical situation is described in this paper. The measured strain changes on gauge probe are caused not only by the stress changes evocateg by progress of long wall. The some deformation started imediatelly after instalation when the long wal didn't move. In paper are discussed the eventu alities of this phenomenon too., Lubomír Staš, Kamil Souček and Jaromír Knejzlík., and Obsahuje bibliografické odkazy
Fluid inclusions in carbonate-dominated veinlets from selected Czech Upper Paleozoic basins display large variations in salinity (0-25 wt. % eq. NaCl/CaCl2) and smaller variations in the homogenization temperatures (41-112 °C). We suggest that the trapped fluids represent a mixture dominated by heated formation fluids., Jiří Zachariáš and Jiří Pešek., and Obsahuje bibliografii
Selected mechanical properties of unidirectional composites with polysiloxane-derived matrix and continuous basalt fibres reinforcement are presented. A special attention is devoted to the impact of long term exposition in hot air (aimed as a simulation of the anticipated operating conditions) to the composite failure under flexural load. The investigated composites worsened their properties after treatment in air at elevated temperature (650 - 750 °C). The originally non-catastrophic flexural failure changed to a brittle fracture, which was accompanied with a flexural strength decrease. The coalescence of fibres and their strong interaction with the matrix are probably the main reasons for the onset of brittleness. Unless these drawbacks are resolved the service temperature of the composites in air will probably not exceed approximately 500 °C., Petr Glogar, Martin Černý and Zdeněk Tolde., and Obsahuje bibliografii
The main assumption of this research was to check and verify the behaviour of a few EPN (European Permanent Network) stations on both sides of the Teisseyre-Tornquist zone (T-T zone), which is located on Polish territory and crosses Poland almost in half. The selected EPN stations’ time series were a subject of frequency and phase analysis. The main purpose of the research was to verify if there is any correspondence between stations located on one and on the other side of the T-T zone. The idea was also to check if any geological phenomena occurs on examined stations through the behaviour of the stations. The chosen period of research was between 2003 and 2008. The stations’ selection is not coincidental, VLNS, LAMA, BOGO, JOZE, BOR1 and WROC were chosen, because they had the longest and constant solutions provided by EPN. Using wavelets as a tool for analysis, the authors detected biases in time series on chosen EPN stations (near T-T zone). Applying multiresolution wavelet analyses on different stations in the component Up the frequency bands were achieved. The authors decided to analyze the low-frequency bias (wavelet approximation band). The reason of using this tool was to analyze the frequencies and also to compare the frequency phase, in order to have more complex analyses of physical phenomena of the T-T zone in Poland., Pawel Kaminski, Mariusz Figurski, Karolina Szafranek and Krzysztof Kroszczyński., and Obsahuje bibliografii
A Global Navigation Satellite System (GNSS) software library called G-Nut has been devel oped at the Geodetic Observatory Pecný (GOP) since 2011. Several applications built of the library will be provided as an open source in 2013 and consequently users are able to modify source code and use it for processing their own data free of charge. The main purpose of the project is to create a programming package suitable for implementing various end-user a pplications such as kinematic position estimation, long-term permanent station coordinates monitoring, zenith tropospheric delay estimation, satellite clock estimation and others. The library is written in C++ programming language following the object-oriented concept. Basic class structure implementing inputs/outputs and product/d ata containers support both real-time and post-processing modes. Integration of all available global navigation satellite systems (GPS, GLONASS, Galileo, BeiDou, QZSS) as well as new tracking signals is properly handled. The configuration is governed through the XML format. The estimation model currently supports the least square adjustment, the Kalman and square root covariance filtering methods based on processing undifferenced data and fixed precise orbit and clock products. The estimated state vector includes receiver coordinates and clocks, troposphere zenith path delays and initial carrier phase ambiguities. The first applications based on G-Nut library are shown with examples for off-line/online kinematic/static precise point positioning and ultra-fast troposphere estimation., Pavel Václavovic, Jan Douša and Gabriel Györi., and Obsahuje bibliografické odkazy
A new observation network has been built to observe the surface manifestations of undermining at Gabriela locality. This locality lies in the Czech part of the Upper Silesian Coal Basin and the history of the hard coal underground exploitation is more than 150 years long here. Recently, the last coal mining panel was started to be exploited here. Its location and mining parameters are very suitable for the analysis of the actual and future surface changes caused by undermining. The fixed points of the observation network are surveyed by geodetic GNSS me thod. This method enables the evaluation of both vertical subsidence and horizontal displacements. Such complex evalua tion of processes on the surface of the undermined territory makes it possible to understand the progress of the subsidence depression and to capture the final phase of the surface undermining changes, i.e. the phase of the subsidence decline., Vlastimil Kajzar, Hana Doležalová, Kamil Souček and Lubomír Staš., and Obsahuje bibliografické odkazy