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In Hungary four extensometric observatories were established in the last two decades. The extensometers were installed primarily for observations of Earth tides. A 15-year continuous data series (1991–2005) was recorded at the Sopronbánfalva station and a 7-year record (1993–1999) was obtained at the Pécs station. The length of the measured continuous data series at the two other stations (Bakonya and Budapest) is only a few years. The long-term data records were also applied to the investigation of long-periodic deformations caused by recent tectonic movements. To get an insight into the present day tectonic processes on the margin of the Pannonian Basin, the measurement results of two additional stations (Vyhne in Slovakia and Beregovo in Ukraine) were also included into the investigations. The seasonal variations in the long data series due to temperature and air pressure effects were eliminated. The residual curve – after the correction of the seasonal effects and filtering the “high frequency” components (e.g. earthquakes, Earth tides, etc.) – contains the instrumental drift. It is impossible to determine this curve mathematically. It can be diminished by special instrumental solutions and by regular calibration of the instruments. This paper shows methods and possible solutions how the instrumental drift was investigated and eliminated in order to get the most reliable data for studying recent tectonic movements. The reliability of the extensometric measurements was tested by the tidal evaluation of the data series. The results of the observations show that the Pannonian Basin is under compressive stress. The strain rates measured by extensometers on the margin of the basin are about three orders of magnitude higher than the intra-plate strains obtained by GPS measurements. The reason for this large difference arises from the interaction between the plate boundary and intra-plate forces and from the different measurement techniques. Investigations showed that the rate of the tectonic movements varies, and depends on the local geographical and topographical conditions. 相似文献
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Bengt G. Martinsson Göran Frank Sven&#;Inge Cederfelt Olle H. Berg Besim Mentes Giorgos Papaspiropoulos Erik Swietlicki Jingchuan Zhou Michael Flynn Keith N. Bower Tom W. Choularton Jyrki Mäkelä Aki Virkkula Rita Van Dingenen 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):801-814
The microstructure of orographic clouds related to the aerosol present was studied during the second Aerosol Characterisation Experiment (ACE‐2). Very high cloud droplet number concentrations (almost 3000 cm−3 ) were observed. These high concentrations occurred when clouds formed on a hill slope at Tenerife in polluted air masses originating in Europe that had transported the order of 1000 km over the Atlantic Ocean. The validity of the measured droplet number concentrations was investigated by comparing with measurements of the aerosol upstream of the cloud and cloud interstitial aerosol. Guided by distributions of the ratios between the measurements, three criteria of typically 30% in maximum deviation were applied to the measurements to test their validity. Agreement was found for 88% of the cases. The validated data set spans droplet number concentrations of 150–3000 cm−3 . The updraught velocity during the cloud formation was estimated to 2.2 m s−1 by model calculations, which is typical of cumuliform clouds. The results of the present study are discussed in relation to cloud droplet number concentrations previously reported in the literature. The importance of promoting the mechanistic understanding of the aerosol/cloud interaction and the use of validation procedures of cloud microphysical parameters is stressed in relation to the assessment of the indirect climatic effect of aerosols. 相似文献
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Gbor Újvri Gyula Mentes Lszl Bnyai Jnos Kraft Attila Gyimthy Jnos Kovcs 《Geomorphology》2009,109(3-4):197-209
The banks of the River Danube are one of the most susceptible areas to mass wasting in Hungary. In 2007, a large slump began to develop along the Danube at Dunaszekcső and jeopardized properties on land and navigation in the river. Several factors such as geological, hydrogeological and morphological conditions, recurrent flooding and erosion by the Danube led to a gradual development of the large rotational slide. Slope failure has been monitored using GPS, precise levelling techniques and tiltmeters since October 2007. The expected location of the maximum lateral displacement and extrusion was indicated by GPS measurements from the middle of November 2007. The main phase of the slope failure evolution, i.e. the rapid movement on 12 February 2008 was indicated by accelerated tilting of the southern moving block prior to slumping. Small rise of the relatively stable part of the slope was measured after the rapid movements, which may be explained either by the elastic rebound along the slip surface, or by the intrusion of some plastic material into the lower section of the slope.Comparison of geodetic datasets and field observations with the timing of rainfall and water level changes of the Danube suggested that hydrological properties (subsurface flow processes, soil physical properties, infiltration, and perched water table) were primarily responsible for initiation of the studied slump. A model of slope failure evolution is proposed here based on the monitoring and field observations. 相似文献
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Yurdanur Sezginer Unal Elcin Tan S. Sibel Mentes 《Theoretical and Applied Climatology》2013,112(1-2):339-350
Global warming is one of the greatest environmental, economic, and social threats in the world. There are many assessments to estimate climate variability over many regions. A change in the Earth’s surface temperature leads to increase in extreme temperature events, which are harmful to the ecosystem, and moreover, they create danger on human health. In this study, we have selected the western part of Turkey as the study area, since climate change projections for Turkey point out that the highest temperature change can be expected on this region during summer, and the Turkish population is very dense here to be affected by extreme events. We have used apparent temperatures to define the heat waves which we have determined their frequencies for the summer months (June–August) of 1965–2006. Since the regional comparisons of station results are intended, we selected the 90th percentile value for each station as a threshold value to be used in the delineation of heat waves. Then, the number of heat waves is determined by imposing the constraint that apparent temperatures stay above the threshold value at least for three consecutive days. Then, the changes in the number of hot days and heat waves and also their durations are analyzed by using the linear least square method. We have found that the number of hot days, heat waves, and heat wave durations is increased between 1965 and 2006 on the western part of Turkey. Additionally, their rate of change is larger within the last decade and extremes are frequently observed after 1998. Regional distributions show that the tendency of the number of heat wave events increases towards the southern latitudes of the domain. Moreover, we investigated the relationship between the number of hot days and the sea surface temperatures of the Mediterranean Sea and Black Sea. Correlation analyses are carried out by the number of hot days and averaged sea surface temperatures on the regions of the western, central, and eastern Mediterranean Sea and the Black Sea. It is found that the number of hot days of west Turkey is better correlated with the sea surface temperatures averaged over eastern Mediterranean and Black Seas. The number of heat waves is found significantly correlated with the fire occurrences for most of the stations. 相似文献
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In this paper, a fuzzy fault tree analysis methodology for spread mooring systems is presented. The methodology combines the effects of operational failures and human errors under fuzzy environment for the spread mooring configurations. In conventional fault tree analysis (FTA), which is an established technique in hazard identification, the ambiguous and imprecise events such as human errors cannot be handled efficiently. In addition to this, the tolerances of the probability values of hazards are not taken into account. Moreover, it is difficult to have an exact estimation of the failure rates of the system components or the probability of the occurrence of undesired events due to the lack of sufficient data. To overcome these disadvantages, a fault tree analysis based on the fuzzy set theory is proposed and applied to the spread mooring system alternatives. Furthermore, sensitivity analysis is carried out based on the fuzzy weighted index (FWI) in order to measure the impact of each basic event on the top event. The results show that the fuzzy fault tree risk analysis method (FFTA) is more flexible and adaptive than conventional fault tree analysis for fault diagnosis and hazard estimation of spread mooring systems. 相似文献
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Erik Swietlicki Jingchuan Zhou David S. Covert Kaarle Hämeri Bernhard Busch Minna Väkeva Ulrike Dusek Olle H. Berg Alfred Wiedensohler Pasi Aalto Jyrki Mäkelä Bengt G. Martinsson Giorgos Papaspiropoulos Besim Mentes Göran Frank Frank Stratmann 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):201-227
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In spite of the appearance of new measurement methods in geodetic survey, the importance of the bubble level has not decreased.
The increase of accuracy is one of the most important tasks of geodetic research. In this connection, the reliability of the
testing of high-precision bubble levels must also be increased. This purpose is served by an apparatus for testing bubble
vials which fulfills up-to-date demands. The smallest measurable rotation angle is 0.1 second of arc, the smallest measurable
displacement 0.01 mm. The values can be digitized. 相似文献
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