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51.
On the selection of GMPEs for Vrancea subcrustal seismic source 总被引:2,自引:0,他引:2
Radu Vacareanu Florin Pavel Alexandru Aldea 《Bulletin of Earthquake Engineering》2013,11(6):1867-1884
The Vrancea subcrustal seismic source is characterized by large magnitude ( $M_{W} \ge 7$ ) intermediate-depth earthquakes that occur two or three times during a century on average. In this study several procedures are used to grade four candidate ground motion prediction equations proposed for Vrancea source in the SHARE project. In the work of Delavaud et al. (J Seismol 16(3):451–473, 2012) four ground motion prediction models developed for subduction zones (Zhao et al. in Bull Seism Soc Am 96(3):898–913, 2006; Atkinson and Boore in Bull Seism Soc Am 93(4):1703–1729, 2003; Youngs et al. in Seism Res Lett 68(1):58–73, 1997; Lin and Lee in Bull Seism Soc Am 98(1):220–240, 2008) are suggested as suitable for Vrancea subcrustal seismic source. The paper presents the appropriateness analysis of the four suggested ground motion prediction equations done using a dataset of 109 triaxial accelerograms recorded during seven Vrancea seismic events with moment magnitude $M_{W}$ between 5.4 and 7.4, occurred in the past 35 years. The strong ground motions were recorded in Romania, as well as in Bulgaria, Republic of Moldova and Serbia. Based on the ground motion dataset several goodness-of-fit measures are used in order to quantify how well the selected models match with the recorded data. The compatibility of the four ground motion prediction models with respect to magnitude scaling and distance scaling implied by strong ground motion dataset is investigated as well. The analyses show that the Youngs et al. (Seism Res Lett 68(1):58–73, 1997) and Zhao et al. (Bull Seism Soc Am 96(3):898–913, 2006) ground motion prediction models have a better fit with the data and can be candidate models for Probabilistic Seismic Hazard Assessment. 相似文献
52.
53.
Felix Borleanu Mihaela Popa Mircea Radulian Johannes Schweitzer 《Journal of Seismology》2011,15(3):431-442
The BURAR seismic array, located in Northern Romania (Bucovina region), is designed to monitor events located in an area poorly
covered by other existing seismic stations. In order to use the BURAR array for single-station locations, it is crucial to
calibrate the azimuth and slowness parameters, which are currently used in array techniques to locate earthquakes, blasts
or nuclear explosions. The goal of this study is to apply “f–k” and plane wave fit techniques in order to constrain the slowness
and azimuth parameters at BURAR for teleseismic, regional and local events. The analysis was carried out using P and S waves
recorded for events occurred between 2004 and 2008 within a radius of 50° around BURAR. The azimuth values obtained applying
both methods strongly deviated from the theoretical values for regions like Central Turkey, Bulgaria, Dodecanese Islands and
other parts of Greece, while the ray parameter deviations with respect to a 1-D IASP91 reference model are less significant.
For the local events, the anomalies are smaller, except the particular case of Vrancea intermediate-depth earthquakes for
which strong azimuth deviations (33.5°), both positive and negative, are observed. We investigate how these systematic deviations
in azimuth are explained by the structure lateral heterogeneities which characterize the study region. 相似文献
54.
The effect of the orbital motion on the light curve of a pulsating star has been evaluated by means of the amplitude and phase spectra synthesis based on the instantaneous pulsation phase concept. The role of the binary system's geometry (circular or eccentric orbit) and the possibility of binarity diagnosis are also emphasized. 相似文献
55.
Publisher's announcement 相似文献
56.
C. E. Jones A. Molak T. A. A. Sigut A. de Koter A. Lenorzer S. C. Popa 《Monthly notices of the Royal Astronomical Society》2009,392(1):383-390
Lenorzer et al. introduce ratios of hydrogen infrared recombination lines as a diagnostic tool to constrain the spatial distribution and physical condition of circumstellar material around hot massive stars. They demonstrate that the observed line flux ratios Hu14/Brα and Hu14/Pfγ from different types of objects associated with circumstellar material, such as Be stars, B[e] stars, and Luminous Blue Variable (LBV) stars are well separated in a diagnostic diagram. In this paper, we investigate this diagnostic tool using a non-LTE disc code developed by Sigut & Jones focusing on Be discs. We find good agreement between the empirical and predicted locations of Be stars in the Hu14/Brα versus Hu14/Pfγ diagram and show that indeed this diagnostic tool can be used to constrain basic properties of the discs of these stars. 相似文献
57.
58.
Adina-Eliza Croitoru Iulian-Horia Holobaca Catalin Lazar Florin Moldovan Alexandru Imbroane 《Climatic change》2012,111(2):393-410
Air temperature variability and trends in Romania were analysed using monthly, seasonal, and annual datasets. Temperature
data of winter wheat season were also analysed. The Mann-Kendall test, Sen’s slope estimate, the sequential version of the
Mann-Kendall test, the Pettitt test and spatial and temporal hierarchical cluster analyses were used. First, the datasets
were checked for changing points. The 106-year period was divided into two long periods of 100 years each to verify the importance
of a very short interval in changing of general trends; after that it was divided into three shorter periods of 35–36 years
each. The main conclusions are as follows: the 6 years making up the difference between the two long periods are very important
in the context of the recent global warming; the three shorter periods analysis indicate some fluctuations rather than continuous
warming. The latest short period is the most relevant for global warming. Spatial hierarchical cluster analysis indicated
the existence of two distinctive groups. One of them, which includes stations in the south-east part of the country, seems
to be influenced by the Black Sea surface temperature. Temporal hierarchical cluster analysis reveals that annual data series
have the closest relation with the summer data series. Further, the impact of temperature changes on winter wheat phenology
was determined using a phenology simulation performed with the model from the Decision Support System for Agrotechnology Transfer
v. 4.0.2.0 platform. Earlier occurrences of anthesis and maturity were noticed for several regions in the country. 相似文献
59.
Jaroslav Lexa Ioan Seghedi Karoly Németh Alexandru Szakács Vlastimil Koneĉny Zoltan Pécskay Alexandrina Fülöp Marinel Kovacs 《Central European Journal of Geosciences》2010,2(3):207-270
Neogene to Quaternary volcanic/magmatic activity in the Carpathian-Pannonian Region (CPR) occurred between 21 and 0.1 Ma with a distinct migration in time from west to east. It shows a diverse compositional variation in response to a complex interplay of subduction with rollback, back-arc extension, collision, slab break-off, delamination, strike-slip tectonics and microplate rotations, as well as in response to further evolution of magmas in the crustal environment by processes of differentiation, crustal contamination, anatexis and magma mixing. Since most of the primary volcanic forms have been affected by erosion, especially in areas of post-volcanic uplift, based on the level of erosion we distinguish: (1) areas eroded to the basement level, where paleovolcanic reconstruction is not possible; (2) deeply eroded volcanic forms with secondary morphology and possible paleovolcanic reconstruction; (3) eroded volcanic forms with remnants of original morphology preserved; and (4) the least eroded volcanic forms with original morphology quite well preserved. The large variety of volcanic forms present in the area can be grouped in a) monogenetic volcanoes and b) polygenetic volcanoes and their subsurface/intrusive counterparts that belong to various rock series found in the CPR such as calc-alkaline magmatic rock-types (felsic, intermediate and mafic varieties) and alkalic types including K-alkalic, shoshonitic, ultrapotassic and Na-alkalic. The following volcanic/subvolcanic forms have been identified: (i) domes, shield volcanoes, effusive cones, pyroclastic cones, stratovolcanoes and calderas with associated intrusive bodies for intermediate and basic calclkaline volcanism; (ii) domes, calderas and ignimbrite/ash-flow fields for felsic calc-alkaline volcanism and (iii) dome flows, shield volcanoes, maars, tuffcone/tuff-rings, scoria-cones with or without related lava flow/field and their erosional or subsurface forms (necks/ plugs, dykes, shallow intrusions, diatreme, lava lake) for various types of K- and Na-alkalic and ultra-potassic magmatism. Finally, we provide a summary of the eruptive history and distribution of volcanic forms in the CPR using several sub-region schemes. 相似文献
60.
The water leakage in the urban areas causes a continuous rise in the water table, with harmful effects. An experimental drainage
system, based on horizontal well technology, was designed and implemented in a populated area. Groundwater flow modeling was
used to assess the hydrodynamic efficiency of the system through drain conductance parameter estimation. 相似文献