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3. Analysis of vertical movements detected by radar interferometry in urban areas

Creator:
Kadlečík, Pavel, Vladimír Schenk, Seidlová, Zuzana, and Zdeňka Schenková
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, poddolování, undermining, Praha (Česko), Ostrava (Česko), Prague (Czechia), Ostrava (Czechia), InSAR, PSI, subsidence, 7, and 551
Language:
English
Description:
Persistent Scatterer Interferometry (PSI), a remote sensing technique, is used for detecting surface deformation in the cities of Prague and Ostrava. PSI is able to detect vertical movements with an accuracy of less than 1 mm for a long time series of the SAR data, but the maximum detectable rate of movement is only a few centimetres per year. This technique is quite suitable for detecting recent movements in most Prague localities. On the other hand, in Ostrava and its surroundings, affected by undermining, where subsidences (1992-2006) amount to decimetres per year, movements cannot be fully detected by the PSInSAR technique. The paper presents results of analysing PSI data for two localities in Prague and one locality in the Ostrava areas. The localities are strictly situated in built-up areas with many suitable reflectors. Data from the ERS-1/2 and ENVISAT satellites covering a 13-year period for the Prague (1992-2005) and a 14-year period for the Ostrava (1992-2006) area were used. Annual movement velocities and time-series of reflectors were determined. At these three localities, where different types of movements were identified, the application and possible limitations of PSI in urban areas are shown., Pavel Kadlečík, Vladimír Schenk, Zuzana Seidlová and Zdeňka Schenková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Data processing of GNSS observations of the GEONAS network: effects of extreme meteorological conditions

Creator:
Grácová, Milada, Mantlík, František, Vladimír Schenk, and Zdeňka Schenková
Format:
print, bez média, and svazek
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, GPS sítě, data, GPS netwoks, GPS permanent observatories, time series, meteorological effect, 7, and 551
Language:
English
Description:
The Institute of the Rock Structure and Mechanics AS CR operates the GEONAS network that now consists of 17 perm anent GPS observatories. The outliers and in consistencies occur within the time series observed in the winter season 200 5/2006 for the position of the GNSS antennas of the observatories SNEC and BISK located high in the m ountains, at th e Sněžka Mt. (1602 m, the Giant Mts.) and the Biskupská kupa Mt. (890 m, the Jeseníky Mts.) respectively. Therefore web cameras and meteorological sensors were in stalled at GEONAS observatories located in the mountain regions. The snow coverage and other meteorological influences affecti ng the antennas monitoring GPS signals at these observatories were estimated. The individual photos were analyzed and compared to variations in the time series to obtain the time series for winter seasons reducing the snow coverage effects., Milada Grácová, František Mantlík, Vladimír Schenk and Zdeňka Schenková., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. GEONAS - geodynamic network of permanent GNSS stations within the Czech Republic

Creator:
Vladimír Schenk, Zdeňka Schenková, Cajthamlová, Milada, and Fučík, Zdeněk
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, dálkové ovládání, geodynamika, remote control, geodynamics, Česká vysočina (pohoří), Bohemian massif, permanent GNSS stations, IRS operational center, GEONAS network, time series, 7, and 551
Language:
English
Description:
To investigate the geodynamic pattern of the Bohemian Massif in Central Europe, the GEONAS network of permanent GNSS stations was established. It now consists of 18 stations, recorded both the NAVSTAR and GLONASS positional signals; they are located along the tectonic zones of the Massif in order to monitor any movement activities. Yet other stations are still planned to be built, and some recent stations are to be moved within these active areas to increase their local distribution density. The GNSS data are processed by the use of Bernese GPS software 5.0. The time series of station positions give fundamental information for both regional and local geodynamic studies. The GEONAS network covers an area of 400 by 220 km, and it allows the effects of dynamic processes going on inside the Earth’s crust, as well as the upper lithosphere to be monitored. A few examples of geodynamic interpretations are presented here., Vladimír Schenk, Zdeňka Schenková, Milada Cajthamlová and Zdeněk Fučík., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Gravity measurements in the region of the geodynamic network HIGHLANDS (the Bohemian massif)

Creator:
Kujal, Roman, Vladimír Schenk, and Zdeňka Schenková
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodynamika, geodynamics, Česká vysočina (pohoří), Bohemian massif, gravity measurement, geodynamic network HIGHLANDS, geodynamic processes, 7, and 551
Language:
English
Description:
During 2007 and 2008 there were realized gravity measurements using the relative gravimeter Scintrex CG-5 on sites of geodynamic networks HIGHLANDS and fundamental gravity sites of the Czech Gravity Reference Network. The gravity measurements were concentrated on monitoring the long-term trends of gravity acceleration changes among individual measurement sites. The methodology of measurement was optimized and preliminary time changes in gravity differences among sites were determined., Roman Kujal, Vladimír Schenk and Zdeňka Schenková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7. Horizontal strain 3He/4He ratio and intra-plate earthquake swarms

Creator:
Vladimír Schenk and Zdeňka Schenková
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, zemětřesení, earthquake, Čechy západní (Česko), Bohemia, Western (Czechia), horizontal strain, 3He/4He ratio, intra-plate earthquake swarms, 7, and 551
Language:
English
Description:
In the West Bohemian region, Central Europe, the volcanic activity appeared in late Tertiary, the Miocene. The present intraplate magmatic activity makes itself felt by flows of gaseous and liquid fluids, enhanced geodynamic mobility of geological structures and generation of earthquake swarms. Position data of two permanent Global Navigation Satellite Systems (GNSS) stations located in the region were used to calculate the time variations of the horizontal strain field that were compared with the 3He/4He ratios and earthquake swarm occurrences. The strains and 3He/4He ratios displayed a positive relation supported by the earlier opinions on the dependence of the dynamics of the region on the fluid occurrence. Analysis of these quantities observed in 2006-2007 period indicated when the compressions calmed and the 3He/4He ratios grew then the earthquake events occurred. It presumes the detected variations relate to compressions and extensions in the region. The strain field changes monitored during the 2008 swarm proved the relation found above. The observed connections could be applied in future at selected regions in earthquake forecast procedures., Vladimír Schenk and Zdenka Schenková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. Microstructure of selected metamorphic rock types: application of petrographic image analysis

Creator:
Šachlová, Šárka, Vladimír Schenk, and Zdeňka Schenková
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, metamorfované horniny, mikroskopie, metamorphic rocks, microscopy, texture, structure, kinematic indicators, 7, and 551
Language:
English
Description:
Microscopic techniques, such as polarising microscopy and scanning electron microscopy with energy dispersive spectrometer (SEM/EDS), were used in combination with petrographic image analysis with the aim of a quantitative determination of the mineral composition, rock microstructure, and degree of metamorphism of selected quartz-rich metamorphic rock types. Sampled orthogneiss rock types are mainly composed of feldspar, quartz, biotite, and amphibole. The grains are less isometric, elongated, having smooth boundaries, and showing a weak preferential orientation. The deformation and recrystallization characteristics of quartz indicate high-temperature recrystallization (the grain boundary migration recrystallization mechanism). Schist and phyllite rock types are preferentially very-fine to fine-grained, showing a strong shape preferred orientation. Their sedimentary origin was indicated by the presence of graphite. The deformation and recrystallization characteristics of the quartz indicate low temperature conditions of their metamorphism., Šárka Šachlová, Vladimír Schenk and Zdeňka Schenková., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public