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EN
In the area of carbonate or karst Dinarides, besides the dominant carbonate rocks and subordinate clastics, in more places more significant mass of chemical sediments can be found, represented by gypsum and anhydrite. As chemical sediments are specifically lighter than overlying rocks, they have been, during the long geological history, trying to achieve isostatic equilibrium, or get out on the ground surface. In recent times, in areas with chemical sediments, a larger tectonic activity is noted than in the wider environment. This is certainly reflected in increased vertical and tangential displacements along major faults in relation to the surrounding area, which are built mainly of carbonate deposits. Determining the amount of movement of diapiric bodies, as absolute and relative, using the most modern surveying methods, precisely would assist the understanding of the tectonic movements and recent structural relations in a wider area
EN
Since 1997 till 2008, several series of precise GPS measurements have been conducted on specially stabilized points of Geodynamical Network of City of Zagreb with purpose of investigation of tectonic movements and related seismic activity of the wider area of the City of Zagreb. From this series of GPS measurements geodetic model of tectonic movements has been created. In the area of interest, independent geological investigations have been conducted through even longer period of time which resulted in geological model of tectonic movements. Comparison and correlation of these two independent models will be presented in this paper.
3
Content available Conceptual model of geotechnical information system
EN
Geological, geodynamical and hydrological research in Zagreb area resulted in several spatial data of different lineage, coordinate systems and resolution. The goal of this paper is the gathering of data in a unique geotechnical information system, which will br the basis for further analysis. We are using ArcGIS modules for spatial and geostatistical analysis. Geotechnical information systems can be used to prevent, mitigate and alleviate damage caused by the natural disasters such as eartquakes and landslides. However, the geotechnical data bases have not been utilized extensively. Examples of using the data bases this chapter for seismic hazards assessment, planning for new structures, ground water hydrology, disaster mitigation systems of gas pipelines, and infrastructure management systems are presented.
EN
Recent advances in GPS-technology (GNSS) enable hydrographic surveyors to capture the topography of the bottom and the water surface with even more accuracy. Faculty of Geodesy, University of Zagreb, recently acquired the latest technology for performing the precise hydrographic surveying: Trimble R8 GNSS receiver that is going to be used with already used echo sounding equipment. The GSM signals are used for transmitting corrections from the base station to the rover. Thus, it is possible to use single-frequency DESO 14 for two-frequencies bathymetry through repeating the course of the vessel on exactly the same points with both transducers. It is expected that the new technology shall yield more accurate results and increase measurement speed, because the OTF times should be significantly shortened.
EN
During last 10 years, geodesists from the Faculty of Geodesy, University of Zagreb, together with geologists and tectonicians established and performed a number of series of GPS-measurements on the Geodynamic Network of the City of Zagreb. The results of these campaigns emphasized the spots with higher level of geodynamic activity, resulting in damages on objects: houses, walls, churches. Therefore, the technology of threedimensional laser scanning has been employed in order to capture much more detailed picture of fast movements. In the first experimental phase of the project, only rapidly sliding areas are observed. The main hypothesis of proposed research is to check if the technology of precise laser scanning is able to produce comparable point clouds showing the movements of objects in the field. As an additional source of information, this research should contribute to the better understanding of the processes below the Earth surface.
6
EN
This paper summarizes recent research activities on merging the geodetic, geologic and neotectonic evidence of geodynamics in Croatia. The area of the City of Zagreb, which is the boundary zone of Eastern Alps, Dinnarides and Pannonian Basin is included as well. It is shown here that the evidence for fractures of Eastern Adriatic differs from the previous hypotheses. This conclusion is derived from the results of various geodetic measurements: satellite positioning (GPS), astro-geodetic measurements of deflections of the vertical. These results are combined with geologic measurements and results of seismic activity studies in order to give more detailed and more accurate picture of the current situation in the tectonically very active region of Dinnarides. Several GPS-campaigns performed in the City of Zagreb area are examined as well. Due to the proximity of Croatian capitol, special attention has been paid to the effects of possible hazard on construction code.
EN
Activities on this work-package subgroup include preparation activities at the University of Zagreb, Faculty of Geodesy and field reconnaissance in the area of the Plitvice Lakes National Park. The combination of equipment has been tested in the field and it is now ready to be deployed in the Plitvice Lakes test area. The goal is to measure the Lake Koyak with the combination of precise bathymetry and RTK GPS (Real Time Kinematics). In the area of Plitvice Lakes, we were looking for the best positions (sky clearance, obstacles, satellite visibility, ground stabilization) for future geodynamic GPS-measurements. At the same time, we have chosen the points which will be used as base points/or hydrographic measurements using the RTK-method. The cooperation with the Croatian Hydrometeorological Institute was established in order to compare the datasets of previous hydrological measurements with current situation in the Lakes. In cooperation with the tectonic experts we prepare the structural map of the area of the Plitvice Lakes in order to find better explanation for possible movements of tectonic units in the area. The geological situation is particularly important for hydrologic assessment since the loss of mter (lowering of water level) in the lakes is caused by faults.
8
Content available remote Geodetic and geologic research of recent tectonic activity in Dinarides
EN
Initial tectonic movements of Adriatic Microplate result in dominating compression in the area ofDinarides. Collected structural data, compared with surface and depth data, with seismological and geodetic measurements taken in the account enabled the classifications of structures. Deformations and movements of structures directly depend on the stress orientation. This orientation varies from between 340-160° to 30-210°. In order to visualize the stress orientation, formation of different types of structures and their movements, examples of compressional structures are shown, as well as rotations of structures and conditions of creation of extensional structures. Finally, the map with fault zones is included, too. The data show narrowing of the area of Adriatic Microplate and the existence of its southern and northern part. Both parts are changing movement directions, leading to more tectonic activity. In active areas, formation of structures is recognised, and causality with fault locations and seismic activity is established. The amplitudes of tectonic movements derived from geodetic measurements between 1994 and 1998 represent important contribution for better understanding the tectonic activities in the area.
9
Content available remote Geodetic and geologic research of recent tectonic activity Dinarides
EN
Initial tectonic movements of Adriatic Microplate result in dominating compression in the area of Dinarides. Collected structural data, compared with surface and depth data, with seismological and geodetic measurements taken in the account enabled the classifications of structures. Deformations and movements of structures directly depend on the stress orientation. This orientation varies from between 340-160° to 30-210°. In order to visualize the stress orientation, formation of different types of structures and their movements, examples of compressional structures are shown, as well as rotations of structures and conditions of creation of extensional structures. Finally, the map with fault zones is included, too. The data show narrowing of the area of Adriatic Microplate and the existence of its southern and northern part. Both parts are changing movement directions, leading to more tectonic activity. In active areas, formation of structures is recognized, and causality with fault locations and seismic activity is established. The amplitudes of tectonic movements derived from geodetic measurements between 1994 and 1998 represent important contribution for better understanding the tectonic activities in the area.
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