The paper presents the results of fieldwork and geodetic surveys carried out on a landslide in Wleń (Western Sudetes, Izerskie Foothills). This reactivated landslide occured firstly in 2011 and later on 16th July 2016, following heavy rainfall in the Lower Silesia region, and covered an area of ca. 1100 m2 above the renovated “Leśny Dwór” guesthouse in Wleń town. The main scarp of the landslide is built of strongly deformed Upper Permian (Zechstein) heterolithic deposits, composing the marginal part of the Wleń Graben - a NW-SE elongated, tectonic sub-unit within the North Sudetic Synclinorium. The landslide was a consequence of undercutting of steep slopes of the Bóbr River valley by anthropogenic activities and loading of the slope surface by blocks and pedestrian paths in the vicinity of the guesthouse. Monitoring of landslide activity was performed using the initial surface model of the slope subjected to mass movements, LiDAR elevation data, as well as 3D point cloud data from a non-metric camera on an Unmanned Aerial Vehicle (UAV). They were used to construct digital elevation models (DEMs) of the area covered by the landslide. The DEM from photogrammetric UAV data was processed using Structure from Motion (SfM) technology. The obtained dataset was verified by additional measurement series from terrestrial laser scanning (TLS). and Kowalski Aleksander, Wajs Jaroslaw, Kasza Damian.
The GRACE satellites have provided gravity field solutions with approximately monthly resolution since April 2002. The monthly solutions enable investigations of the annual, semi-annual and secular mass variations, which mainly occur in a thin layer of the Earth’s surface. By the end of the GRACE science mission in 2017, the time span has increased to 15 years, making the possibility of determining longer-period variations feasible. First attempts to determine multi-annual variations, i.e. periods of some years but less than 10, are presented in this study. A combination of 3 different PSD estimation methods has been used for identifying the regions of multi-annual mass variations. As a result, 8 different areas have been found with significant multi-annual mass variations. The source of multi-annual mass variations in most detected regions can be identified as related to the ENSO cycle. and Kiss Annamária, Földváry Lóránt.
přednášel dne 20. listopadu 1889 F.J. Studnička, Separát z: Hospodář českoslovanský. Roč. XX., and Converted from MODS 3.5 to DC version 1.8 (EE patch 2015/06/25)
Three variants of geophysical excitations and seven different VLBI solutions of celestial pole offsets (CPO) are used to determine period and Q-factor of Free Core Nutation (FCN). Brzeziński’s broad-band Liouville equations (Brzeziński, 1994) are numerically integrated to derive geophysical effects in nutation in time domain. Possible effect of geomagnetic jerks (GMJ) is also considered. Best-fitting values of FCN parameters are estimated by least-squares fit to observed CPO, corrected for the differences between the FCN parameters used in IAU 2000 model of nutation and newly estimated ones; MHB transfer function is used to compute these corrections. It is demonstrated that different VLBI solutions lead to FCN parameters that agree on the level of their formal uncertainties, but different models of geophysical excitations change the results more significantly. Using GMJ excitations always brings improvement of the fit between integrated and observed CPO. The obtained results show that the best fit is achieved when only GMJ excitations are used. Our conclusion is that GMJ are very probably more important for exciting FCN than the atmosphere and oceans. Empirical Sun-synchronous correction, introduced in the present IAU 2000 nutation model, cannot be explained by diurnal atmospheric tidal effects., Jan Vondrák and Cyril Ron., 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.
From 61 coking coals, 36 coal blends were prepared. Using a pilot coke oven, cokes were prepared from both 61 coking coals (Type I cokes) and 36 coal blends (Type II cokes). Coals were characterized by 14 coal characteristics and cokes by Coke Reactivity Index CRI and Coke Strength after Reaction with CO2 CSR. For the study of mutual statistic relationships among experimentally determined characteristics of coals and cokes, the Factor (FA) and Regression Analyses (RA) were used. FA distributed characteristics of coals and Type I cokes into 4 factors while characteristics of coal blends and Type II cokes were distributed into 7 factors. In case of pure coals and Type I cokes, strong relationships with high correlation coefficients (R > 0.60 ) were more abundant than in case of coal blends and Type II cokes. FA was used for the selection of coal characteristics that influence the coke quality the most significantly. These characteristics were then recalculated by RA for the predictions of CRI/CSR of Type I cokes. Predictions of CRI/CSR of Type II cokes were calculated from coal blends by the same procedure. The comparison of the predicted and experimentally determined CRI and CSR indexes showed much more reliable prediction of CRI/CSR indexes calculated from coals than calculated from coal blends. This study also explains the dominant reasons of this observation., Jana Serenčíšová, Zdeněk Klika, Ivan Kolomazník, Lucie Bartoňová and Pavel Baran., and Obsahuje bibliografii
Ultrasonic velocity anisotropy in the rock provides information of variability of the dynamic elastic moduli. Young’s modulus and Poisson’s ratio calculated from waves velocities can be used to determine brittleness index, which is usually used to predict rock susceptibility for hydraulic fracturing. This paper describes laboratory ultrasonic measurements carried out in order to improve hydraulic fracturing designing. The research was conducted over two types of rock: shale and limestone. The samples were cut out perpendicularly and parallel to the bedding planes. Next they were tested for effective porosity and mineral composition using XRD method. Directionally depended seismic velocities revealed noticeable anisotropy of laminated shale, caused by orientation of the bedding planes and weak anisotropy of limestone. Based on the velocities, dynamic elastic moduli and its anisotropy coefficients were determined. Calculations of brittleness index based on Young’s modulus to Poisson’s ratio relation and three types of mineral composition brittleness indexes, revealed strong variability in brittleness for both kind of tested formations. These results show, that different types of brittleness indexes should be used complementary, to better describe fracability of the rock. and Moska Rafal, Kasza Piotr, Maslowski Mateusz.