Geodetic geodynamic studies were conducted in the Wrocław Plain, situated in the SE part of the Central European Subsidence Zone (CESZ). The boundaries of this plain coincide with the outline of the rhomboidal Cainozoic Wrocław Basin. This area has been chosen for detailed examination taking into account the results of previous geodynamic research, pointing to constant subsidence of the Wrocław region. Analysis of drainage network and changeable thicknesses of the Neogene an d Quaternary strata also indicates weak, although stable subsidence of the central part of the Silesian Lowland and relative, small-scale uplift of the Fore-Sudetic region situated in thes outh and an area placed north of the Odra River valley. The studies consisted in measuring elevation changes of benchmarks along lines of precise levelling during 1956-1999 period, establishing a GPS network points, as well as measuring and processing of GPS data acquired during 2008-2010 time span. Displacements of benchmarks of precise levelling lines point to block-type mobility of structures located in the SE part of the CESZ, while GPS measurements indicate deformations related to bending of the Cainozoic sedimentary cover underlain by metamorphic bedrock and Permo-Mesozoic strata. Three years of observations enable us to distinguish two zones typified by compressive deformations being coincident with subsiding areas. One of these zones strikes NW-SE and marks the CESZ axis, the second one, oriented NNW-SSE, fo llows the orientation of a deeply buried Carboniferous-Permian tectonic graben (the Eastern Fore-Sudetic Basin) and a much shallower trough filled with Cretaceous strata in the Opole region. Uplift typifies the Fore-Sudetic Block as well as areas situated close to Opole town and north of the Odra River valley., Piotr Grzempowski, Janusz Badura, Stefan Cacoń, Jan Kapłon, Witold Rohm and Bogusław Przybylski., and Obsahuje bibliografické odkazy
Presently the determination of the velocity field in the global reference frame is possible by using different space techniques and dense terrestrial networks from global to local and regional scales. However, the reliability of such determinations is strongly limited by the restricted number of unmodeled effects. Some of them are periodic (atmospheric or hydrological effects), some instantaneous (natural or man-made seismicity ) or seasons-related (snow cover, freezing). This elaboration deals with the unmodeled effects observed in the ASG-EUPOS (Polish Active Geodetic Network) time series. The whole network consists of over 130 permanent GNSS sites with different levels of stability. The paper presents the analysis of 3-year’s time-series of geodetic coordinates (in the topocentric projection) in order to obtain best-possible local velocity field. On the example of the Sudeten region, where 19 sites are located, the possible effects on the decrease in reliability of the velocity field determination are described. Finally the local velocity field in ITRF and ETRF frames are presented., Janusz Bogusz, Mariusz Figurski, Bernard Kontny and Piotr Grzempowski., and Obsahuje bibliografické odkazy
Analysis of benchmark height changes along national 1st order precise levelling lines crossing the Middle Odra Fault Zone in the Wroclaw area has been presented in this paper. The zone separates Fore-Sudetic Block from the Fore-Sudetic Monocline and is one of the main geological structures in Lower Silesia. Five national precise levelling lines cross the research area: Ząbkowice Śląskie - Wrocław, Syców - Wrocław, Karczów - Wrocław, Kawice - Wrocław oraz Krotoszyn - Wrocław. These levelling lines were measured in 1956-58, 1975-80 and 1999. Changes of benchmark heights have been presented in comparison with geological cross-sections made along the levelling lines. In the result, areas of the greatest relative vertical displacements correlated with geology and tectonics have been found., Piotr Grzempowski, Janusz Badura, Stefan Cacoń and Bogusław Przybylski., and Obsahuje bibliografii