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2. 14C and U - series dating of speleothems in the Bohemian Paradise (Czech Republic): retreat rates of sandstone cave walls and implications for cave origin

Creator:
Jiří Bruthans, Jana Schweigstillová, Petr Jenč, Churáčková, Zdeňka, and Petr Bezdička
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, pískovce, jeskyně, stáří, pseudokras, eroze (geologie), holocén, sandstones, caves, old age, pseudokarst, erosion, holocene, speleothems, 7, and 551
Language:
English
Description:
Speleothems in 6 sandstone caves in the Bohemian Paradise (Český ráj) were dated by means of 14C and U-series methods. Stable isotopes of C and O, FAAS, IR, XRD, XRF and SEM were used to characterize the carbonate material and its source. Stable isotopes (C and O) composition of speleothems in two caves corresponds to values characteristic for cave speleothems in Central Europe. In other caves they indicate evaporation and fast carbon dioxide escape during carbonate precipitation. The speleothems from the Krtola Cave were deposited between 8 and 13 kyr BP. Speleothems were deposited 5-8 kyr BP in the Sintrová, Mrtvé Údolí and U Studánky caves. Calcite coatings on smooth sandstone surfaces in studied caves demonstrate that cave walls did not retreat even a few mm in the last 5-8 kyr since speleothem deposition and are thus not evolving under recent climatic conditions. Most of the cave ceilings and walls are at present time indurated by hardened surfaces, which protect the sandstone from erosion. Sandstone caves probably intensively evolved either during or at the end of the Last Glacial period. There are two different erosion mechanisms which might have formed/reshaped the caves at that time: A) In the case of permafrost conditions: Repeated freeze/melt cycles affecting sandstone pore space followed by the transport of fallen sand grains by minor temporary trickles. We expect that heat was transmitted by air circulating between the cave and the surface; B) Seepage erosion of sandstone during the melting of permafrost, prior forming of case hardening., Jiří Bruthans, Jana Schweigstillová, Petr Jenč, Zdeňka Churáčková and Petr Bezdička., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. 3-D trend of aseismic creep along active faults in western part of the Gulf of Corinth, Greece

Creator:
Stemberk, Josef and Blahoslav Košťák
Format:
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Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, tektonika, geotectonics, Řecko, Greece, active tectonics, 3-D monitoring, fault movements, The Gulf of Corinth, 7, and 551
Language:
English
Description:
Quaternary faulting in the western part of the Gulf of Corinth has been evidenced by geology and geomorphology, as well as by seismic recording. A series of three main normal fault segments are aligned in a steep southern coastal zone of the gulf. These fault segments, 15 to 25 km long, have an average strike of 90° - 105° and a northward dip of about 50° - 75°. Selected fault points were equipped with 3-D crack gauges TM71 during 2002 to monitor movements along the fault planes here, as well as on another fault cutting through the small island of Trizonia near the opposite northern shore of the gulf. Results of the monitoring present relative displacements induced by active tectonic movement s. Generally, the movements recorded on the faults are characteristic of an aseismic linear creep in vertical, i.e. upliftin g/subsiding in rates of mm per year due to uplifts of the Peloponnesian Peninsula. In 2003 a thr ee months long period of fast acceleration of movements was recorded. During this acceleration phase displacements changed to skew uplifting/subsiding with a left-lateral horizontal component. Moreover, horizontal rotation of monitored blocks corresponding to a sy stematic westwards opening of the Gulf was observed with only single eastward opening episodes., Josef Stemberk and Blahoslav Košťák., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. 3D how much can we trust some moment tensors or an attempt of seismic moment error estimation

Creator:
Kolář, Petr
Format:
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Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, seizmicita, seismicity, seismic moment tensor inversion, error estimation, seismic moment decomposition, 7, and 551
Language:
English
Description:
During routine processing of selected events of an active KTB experiment it has appeared doubts concerning data reliability and consequently the reliability of results based on them. In the paper 3 events are studied in detail, full seismic moment tensors, as well as their errors, are determined (by non-linear inversion of P/SH waves ratios). It is shown that for the processed low constrained data moment tensor (MT) can be determined, however the relative error is of order of first tens of percent; the results also considerably depend on the way of data picking, used medium model, way of Cost function construction, etc. Any subsequent geophysical interpretation therefore should takes into account this uncertainty. MTs are finally decomposed into DC and non-DC parts, MTs errors are also transformed., Petr Kolář., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. 3D monitoring of active fault structures in the Krupnik-Kresna seismic zone, SW Bulgaria

Creator:
Dobrev, Nikolai
Format:
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Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, seizmické oblasti, seismic regions, Bulharsko, Bulgaria, 3D monitoring, active faults, co-seismic displacements, Krupnik-Kresna seismic zone, SW Bulgaria, 7, and 551
Language:
English
Description:
The present paper concerns long-term 3D monitoring of active fault structures in the Krupnik-Kresna seismic zone, SW Bulgaria with the use of extensometers TM71. The purpose is to establish the real rates of fault movements in the most seismically active area in Bulgaria. Three points were installed (B6 on Krupnik Fault, and K5 and K12 on Struma Fault), which indicate a recent activity. The fault movements are characteristic with “calm” periods, linear slips, accelerations and sudden displacements. Different regimes of dynamics have been established corresponding to different periods. The greatest dynamics is found at monitoring point B6 along Krupnik Fault: for the whole period of observation the trends are calculated as left lateral slip with 1.88 mm/a and a thrusting with 1.59 mm/a with high correlation coefficients. Co-seismic displacements from local and distant earthquakes were recorded. The significant impact was from M=7.4, 17 August, 1999, Izmit Earthquake, Turkey, showing a shortening of 8.34 mm, a right-lateral slip of 5.09 mm and a thrusting of 0.96 mm. After that, for a short period of time the regime of movement on fault was changed. Movements on the Struma system reveal lower rates. Both points show left-lateral movements, 0.28 mm/a at K5 and 0.09 mm/a at K12, and thrusting with 0.11 mm/a at K5 and 0.72 mm/a at K12., Nikolai Dobrev., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. 3D monitoring of active faults and slope movements in three Bulgarian sites included in cost 625 project

Creator:
Dobrev, Nikolai and Avramova-Tacheva, Elka
Format:
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Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, tenzometrie, svahy, extensometry, slopes (physical geography), fault, slope movement, 3D monitoring, 7, and 551
Language:
English
Description:
The present paper shows the results of 3D monitoring with the use of extensomet ers TM71 performed in Bulgaria in the framework of COST Action 625. This research was performed in selected areas: Simitli graben that is the most seismoactive area in Bulgaria; Madara plat eau - rock scarp with historical monument affe cted by rock toppling; East Rhodopes area - a possibly active fault zone and a large landslide. The most impressive results were established at Simitli graben area with the rate of 2.73 mm/year sinistral movement of Krupnik Fault. Local earthquakes located at NE part of the graben usually influence the movements along this fault. An acceleration of the left latera l movements during calm periods has been established, and respectively, the movements stop (or going in opposite direction) during seismic activity. At Madara site, the results from the 15 years monitoring show subsidence of rock s lices by 0.9 mm per year and si milar rate movement of the slices to South direction. Influence from Izmit earthquake, Vrancea earthquakes and local ones have been established. The monitoring of the fault at General Geshe vo Village, East Rhodopean area started in 2003. The first results show mainly gravitational movements - subsidence of NE block 1.5 mm/year., Nikolai Dobrev and Elka Avramova-Tacheva., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7. 3D monitoring of the selected active tectonic structures in Poland, Italy and Greece

Creator:
Cacoń, Stefan, Kontny, Bernard, and Bosy, Jarosław
Format:
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Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, GPS sítě, GPS netwoks, active tectonics, geodetic monitoring system, local GPS network, crack gauge observation, 7, and 551
Language:
English
Description:
The paper presents the results of geodyn amic research in the fram e of the project COST 625 relating to active tectonic structures’ monitoring on the selected areas in Poland, Italy and Greece. Research was realised using a self-developed control and measurement system. The resu lts of researches for period 2000-2006 indi cate slight movements of observatio n points in the Sudety Mts. reaching several millimetres. However, the results confirm recent mobility of tectonic structures o f this area. Research realised in the Mediterranean Region objects - Gargano, Norcia (Italy) and Kaparelli (Greece) - indicate movements of observation points reaching over a dozen millimetres, particularly on the Gargano area. Continuation of cyclic control measurements on these objects is fully justified ., Stefan Cacoń, Bernard Kontny and Jarosław Bosy., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. 9, 10-bis(chlormethyl)anthracene - curing agent of coal tar pitch

Creator:
Svítilová, Jaroslava, Machovič, Vladimír, and Kolář, František
Format:
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Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, vytvrzování, curing, coal tar pitch, modification, carbonization, 7, and 551
Language:
English
Description:
Modified coal tar pitch was prepared by Friedel-Crafts reaction with 9,10-bis(chloromethyl)anthracene (BCMA). With the aid of IR and Raman’s spectroscopy it was found that BCMA reacted completely with aromatic components of pitch. This modification leads to a significant increase of the carbonisation residue of coal tar pitch without the structure of carbonisate being greatly affected., Jaroslava Svítilová, Vladimír Machovič and František Kolář., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

9. A comparison of numerical models results with in-situ measurement of ground vibrations caused by sheet pile driving

Creator:
Tomáš Petřík, Eva Hrubešová, and Markéta Lednická
Format:
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Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, numerické modelování, numerical modeling, dynamic analysis, Plaxis 2D, sheet pile driving, vibration velocity amplitude, vibration frequency, vibratory hammer, 7, and 551
Language:
English
Description:
This paper pursues the effect of changes in distance and vibration frequency on the vibration velocity amplitude. As an example, we used the vibrating sheet piles at the cons truction of a new multi-functional FEI building on the premises of VŠB - TU Ostrava, at 17 listopadu street. The effect of these changes is monitored both in in-situ measurements and in a simulated real-life situation. The calculation software Plaxis 2D is used for creation of numer ical models. At the close, the results from in-situ measurements are confronted with those achieved from the models., Tomáš Petřík, Eva Hrubešová and Markéta Lednická., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. A feasibility of absolute gravity measurements in geodynamics

Creator:
Pálinkáš, Vojtech, Jakub Kostelecký, and Jaroslav Šimek
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, metrologie, nejistota, metrology, uncertainty, hydrological effects, reproducibility, gravity acceleration, absolute gravimeter, FG5, repeatability, 7, and 551
Language:
English
Description:
The absolute gravity measurements are an important tool for reliable monitoring geodynamic phenomena. Based on the experience with the absolute gravimeter FG5#215 (gravimeter of the Center for Earth Dynamics Research), the accuracy of FG5 absolute gravimeters is presented in this study. The instrumental reproducibility of this meter is characterized by the value of 0.7 μGal. Discussed are important environmental effects on gravity measurements, such as atmospheric and hydrological effects, understanding of which is necessary for correct and reliable interpretation of the repeated absolute gravity measurements in geodynamics., Vojtech Pálinkáš, Jakub Kostelecký and Jaroslav Šimek., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public