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
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 paper presents results of epoch satellite GPS and gravimetric measurements performed on the geodynamic network in central part of the Stołowe Mts. between 1993 and 2009. The research results show significant changes of gravity on most of the points and significant horizontal movement of one point in the central part of the area. The results confirm present day activity of the zone where faults Polický, Bělský and Czerwona Woda Fault Zone exists. In addition, they correspond with the studies of seismic activity in this part of the Sudety Mts., Stefan Cacoń, Jan Kapłon, Bernard Kontny, Josef Weigel, Otakar Švábenský and Jiři Kopecký., and Obsahuje bibliografii
The combination method of results of different space geodetic techniques was recently improved and used to process approximately eight-year data obtained by three space geodetic techniques. The results are compared with the results obtained by the old approach of this method and finally with the solutions of ITRF 2005., Vojtěch Štefka., and Obsahuje bibliografii
Three year monitoring of micro-displacements on four tectonic fracture planes in a tunnel driven by a milling cutter into granitoids of Bohemian Massif revealed micro-movements that develop in certain trends and impulses. Two investigated fractures are of the Krušné Hory Mts. orientation (NE - SW), other two of Sudeten orientation (NW - SE). These have been found the two prevailing fracture orientations in the massif. Results from all the four fractures indicate trends in overfaulting of southern blocks over the northern ones and a stress state model characteristic of approximate N-S compression with overthrust vergence to N. Besides, some impulses were indicated with abrupt occurrence that dominates the development of movements. The first most significant impulse occurred by the end of the year 2004, the second one at the break of 2005/6. The coincidence of the impulses with earthquake events is discussed., Josef Stemberk and Blahoslav Košťák., and Obsahuje bibliografii
To investigate recent crustal movements between northern and southern parts of Moravo-Silesian region of the Bohemian Massif and to find their relation to movements of structure blocks of Moldanubicum, it was decided to establish a regional geodynamic network HIGHLANDS. Seven sites for monitoring GPS signals were built with respect of geological and geophysical materials in the southern area of the Českomoravská vysočina Highlands. So far two epoch 48-hours GPS measurements have been performed in 2005 and 2006 with Ashtech receivers and antennas. GPS monitored data were processed by the Bernese software v. 5.0. The rather preliminary site movements were assessed and discussed from the viewpoint of recent geodynamic motions., Zdeňka Schenková, Vladimír Schenk, František Mantlík and Milada Grácová., and Obsahuje bibliografické odkazy
The motion of Earth’s spin axis in space is monitored by Very Long-Baseline Interferometry (VLBI), and since 1994 also its rate is measured by Global Positioning System (GPS). From the direct analysis of the combined VLBI/GPS solution in the interval 1994.3-2004.6 we recently found that the apparent period of the Retrograde Free Core Nutation (RFCN) grew from original 435 days to 460 days during the past ten years, but the resonance effects yielded a stable period of about 430 days. Now we repeat the same study with VLBI-only data, covering much longer interval (1982.4 - 2005.6). Direct analysis shows again a substantial increase of the apparent period during the last decade or so. The resonant period is given by internal structure of the Earth (mainly by the flattening of the core), so it is highly improbable that it is so much variable. From the same observations we derive corrections of certain nutation terms. A subsequent study of indirect determination of resonance RFCN period from the observed forced nutation terms through the resonance effects proves that the natural resonance period remains stable and is equal to 430.32±0.07 solar days. From this follows that an excitation by outer layers of the Earth (atmospheric, oceanic) should exist, with a terrestrial frequency close to that of RFCN (of about -1.0050 cycles per solar day, i.e. with period of -23h53m mean solar time), invoking the apparent changes of the directly observed RFCN period. Thanks to a close proximity of the resonance, any excitation with this period is extremely amplified so that the excitation necessary to explain the difference can be very small. The atmosphere alone contains enough power to excite the observed changes., Jan Vondrák and Cyril Ron., and Obsahuje bibliografii
Rock landforms in the Sokolský hřbet (ridge) and the adjacent Žulovská pahorkatina (hilly land) have been analysed through detailed field mapping at a scale of 1:10,000; subsequently the spatial distribution of these features was analysed using a DEM within a GIS framework. Particular attention was focused upon the shape of the rock landforms, their arrangement, the aspect of their walls, and their topographic position within the two adjacent geomorphological units. Rock landforms in the Sokolský hřbet include frost-riven cliffs, isolated residual rockforms, and blockfields in metamorphic rocks. In contrast, rock landforms in the Žulovská pahorkatina include rock steps and numerous tors exposed from the basal weathering surface. The Sokolský hřbet has been interpreted as a neotectonically uplifted mountainous region; the rock landforms described here are thought to have formed under periglacial conditions during cold periods in the Pleistocene, whilst the extensive granitoid block accumulations developed on marginal fault scarps are thought to result from the exposure of intensively disintegrated rocks due to uplift. Žulovská pahorkatina has been interpreted as a remodelled stripped etch surface, which has been twice glaciated during the Middle Pleistocene. The rock landforms in both units appear to be structurally and lithologically controlled; moreover, various shapes of granite rock landforms are controlled by various types of jointing and parting. The clear differences recognised in both the rock landforms and overall morphology reflects the considerable disparity associated with relief development between two adjacent morphostructural units; such variability provides evidence for a long polygenetic history within the entire study area., Petra Štěpančíková and Matt Rowberry., and Obsahuje bibliografii
Compact conical strain gauge probe for borehole over-coring rock massif stress measurement (CCBO), based on experiences of K. Sugavara and Y. Obara, has been developed in Institute of Geonics ASCR, v.v.i. from 2004. First generation of CCBO is equipped by simple electronic circuit which requires continuous communication with control computer in the course of measurement. Prototypes of this type probes are used for long term stress changes monitoring induced by longwall advancement in mine. Solving of continuous data communication through rotating drilling tool filled by wash water in course of over-coring is very difficult technical task, which is not possible to solve in terms of grant project. To avoid this problem a development of second generation of CCBO equipped by microprocessor and internal data logger was initialised. Simplified modification of CCBO is developed as a probe for long-term monitoring of rock massif stress changes (Compact Conical Ended Borehole Monitoring - CCBM). Design of both models probes, discussion of measurement errors and technique of sensitivity self-calibration is described., Jaromír Knejzlík, Zdeněk Rambouský, Kamil Souček and Lubomír Staš., and Obsahuje bibliografii