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11.
The Baraba and Kulunda steppes are located in southwestern Siberia in an area with an arid continental climate. This paper presents results of the first study of the hypersaline Lake Krasnovishnevoye(Baraba steppe, TDS(total dissolved solids)=297 g/L, pH 7.88). The major chemical, mineralogical and biological features of the lake were studied and compared to those of Lake Malinovoe, a typical saline neutral lake of Kulunda steppe(TDS=396 g/L, pH 7.63). The phytoplankton composition and the culturable diversity of anoxygenic phototrophic bacteria from Lake Krasnovishnevoye correspond to the ones in the Kulunda lakes. Nevertheless, the peculiarities of water composition and regime of Lake Krasnovishnevoye reduce the biodiversity to prokaryotes and unicellular algae.  相似文献   
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Response of different soils to dynamic loading is of fundamental interest in many engineering, geophysical and environmental studies. Many methods have been proposed to estimate dynamic stability of soils. One more approach, based on laboratory cyclic testing, is discussed in this paper. In our tests, not only the specific features of examined soils, but also different conditions of static and dynamic loading have been taken into account. An analysis of the obtained experimental data explicitly supports the hypothesis of a logarithmic relationship between the axial deformation of soil in cyclic triaxial compression and the number of loading cycles. Evaluation of soil deformation under vibrodynamic loads can also be based on energy approach. The use of critical amount of energy dissipated by soil per its unit volume has been proved to be reliable even in a low dynamic stress range. Convergence of the proposed solution was proved using field measurements and observations. The proposed approach has been applied to evaluate additional settlements of structures founded on the basis of different soil profiles and under various static and dynamic loading conditions.  相似文献   
14.
Many kinds of environmental data are nowadays publicly available, but spread over the web. This article discusses using the Sensor Observation Service (SOS) standard of the Open Geospatial Consortium (OGC) as a common interface for providing data from heterogeneous sources which can be integrated to a user tailored environmental information system. In order to allow for providing user‐tailored and problem‐specific information the adjusted SOS is augmented by a semantic layer which maps the environmental information to ontology concepts. The necessary information fusion from different domains and data types lead to several specific requirements for the SOS. Addressing these requirements we have implemented a SOS which still conforms to the OGC SOS 1.0.0 standard specification. The developed SOS has been integrated in a publicly available demonstrator of our personalized environmental information system. Additionally this article discusses future consequences for the SOS, caused by the recently published SOS 2.0 specification.  相似文献   
15.
Schistous rock can be considered—in a first approximation—as cross‐anisotropic linear elastic material. The determination of the corresponding material constants on the basis of the laboratory investigation of rock samples often fails, as the extraction of appropriate cores proves to be unfeasible (the cores disintegrate if the schistosity is pronounced). In this paper a new method is presented to determine the material constants of a linear elastic cross‐anisotropic rock on the basis of cavity expansion field tests, e.g. with a radial jack. To this purpose, an analytic approximation for the deformation of a hydrostatically loaded cylindrical cavity in cross‐anisotropic rock is derived which serves to the inverse analysis of the material parameters. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
16.
Wildfires are a common experience in Alaska where, on average, 3,775?km2 burn annually. More than 90% of the area consumed occurs in Interior Alaska, where the summers are relatively warm and dry, and the vegetation consists predominantly of spruce, birch, and cottonwood. Summers with above normal temperatures generate an increased amount of convection, resulting in more thunderstorm development and an amplified number of lightning strikes. The resulting dry conditions facilitate the spread of wildfires started by the lightning. Working with a 55-year dataset of wildfires for Alaska, an increase in the annual area burned was observed. Due to climate change, the last three decades have shown to be warmer than the previous decades. Hence, in the first 28?years of the data, two fires were observed with an area burned greater than 10,000?km2, while there were four in the last 27?years. Correlations between the Palmer Drought Severity Index and the Canadian Drought Code, against both the number of wildfires and the area burned, gave relatively low but in some cases significant correlation values. Special emphasis is given to the fire season of 2004, in which a record of 27,200?km2 burned. These widespread fires were due in large part to the unusual weather situation. Owing to the anticyclonic conditions of the summer of 2004, the composite anomaly of the 500?mb geopotential height showed above normal values. The dominance of a ridge pattern during summer resulted in generally clear skies, high temperatures, and below normal precipitation. Surface observations confirmed this; the summer of 2004 was the warmest and third driest for Interior Alaska in a century of climate observations. The fires lasted throughout the summer and only the snowfalls in September terminated them (at least one regenerated in spring 2005). Smoke from the forest fires affected the air quality. This could be demonstrated by measurements of visibility, fine particle matter, transmissivity of the atmosphere, and CO concentration.  相似文献   
17.
We present a catalog of moment tensor (MT) solutions and moment magnitudes, Mw, for 119 shallow (h  40 km) earthquakes in Greece and its surrounding lands (34°N–42°N, 19°E–30°E) for the years 2006 and 2007, computed with the 1D Time-Domain Moment Tensor inversion method (TDMT_INV code of Dreger, 2003). Magnitudes range from 3.2  Mw  5.7. Green's functions (GF) have been pre-computed to build a library, for a number of velocity profiles applicable to the broader Aegean Sea region, to be used in the inversion of observed broad band waveforms (10–50 s). All MT solutions are the outcome of a long series of tests of different reported source locations and hypocenter depths. Quality factors have been assigned to each MT solution based on the number of stations used in the inversion and the goodness of fit between observed and synthetic waveforms. In general, the focal mechanisms are compatible with previous knowledge on the seismotectonics of the Aegean area. The new data provide evidence for strike-slip faulting along NW–SE trending structures at the lower part of Axios basin, close to the heavily industrialized, and presently subsiding, region of the city of Thessaloniki. Normal faulting along E–W trending planes is observed at the Strimon basin, and in Orfanou Gulf in northern Greece. A sequence of events in the east Aegean Sea close to the coastline with western Anatolia sheds light on an active structure bounding the north coastline of Psara–Chios Islands about 20–25 km in length exhibiting right lateral strike-slip faulting.  相似文献   
18.
Average source parameters for three large North Aegean events are obtained from body wave inversion for the moment tensor. The parameters for the events are as follows: The events exhibit dextral strike-slip faulting with theT axis striking NS and nearly horizontal, implying extension in this direction. The focal mechanisms obtained are in agreement with the seismotectonic regime of the North Aegean. It is known that the region is tectonically controlled by the existence of the strike-slip Anatolian fault and its westward continuation in the Aegean, as well as the NS extension the whole Aegean area undergoes.The components of the moment tensor show that the region is dominated by compression in the EW direction which is encompassed by extension in the NS direction. All the events were found to be shallow (10 km) with a source time function of approximately 8 s duration and small stress drop values.The teleseismic long period verticalP-waves exhibited distortions, that could be attributed to lateral inhomogeneities in the source structure or more probably to a nonflat water-crust interface.  相似文献   
19.
Chemical Composition of Some Saline Lakes in the Tuva Region(Russia)   总被引:1,自引:0,他引:1  
正1 Introduction Salt lakes are very interesting natural objects which can be found in different places in the world.Russia is not an exception.Climate conditions are various in Russia,but the climate is not very hot.In Russia there are a lot of places where salt lakes are spread.One of them is the Tuva region where lakes with different compositions are  相似文献   
20.
S-wave spectral analysis is applied to 174 strong motion accelerationrecords to obtain the source parameters of 27 aftershocks(3.1 ML 4.3) of the May 13, 1995, Mw 6.6,Kozani-Grevena (NW Greece) earthquake. The data are derived from atemporary network, of three-component digital accelerographs, deployedwithin the strongly affected area some days after the mainshock occurrence.Site effects were evident in the strong motion records at 3 out of the 4stations used, and a correction was applied to account for theoverestimation of seismic moment due to amplification of thelow-frequency part of the spectrum. The data from this analysis arecomplimented with previously obtained source parameters for earthquakesin Greece, in order to study the applicability of the empirical scalingrelations used so far, towards smaller magnitudes. In general, a goodcorrelation was observed in most cases, validating the use of empiricalrelations that are applicable to the Aegean area. Empirical relations aredetermined between seismic moment and seismic slip, as well as, betweenseismic moment and stress drop, applicable to small magnitude earthquakes(ML < 4.3). Stress drop values were found to be relatively small,ranging from 2 to 41 bars, indicative of inter-plate environments. Thevalues of fc and of fmax were found in good agreement withrelations based on observations from larger worldwide earthquakes.  相似文献   
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