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691.
The complex geoecological works carried out in the St. Anna Trough resulted in the detailed investigation of the water-sediment barrier zone. The physicomechanical properties such as the moisture, the moisture at the flowing boundary, the sedimentation rates, and the strength of the sediments measured and calculated for the upper 10-cm-thick layer of the bottom sediments were used as the main parameters characterizing the barrier zone. These data served as a basis for developing the model of the barrier zone with defining the lithogenesis stages: protosyngenesis??syngenesis??protodiagenegis??early diagenesis. The quantitative estimates of the environmental physicochemical properties presented in this work characterize each of these stages. 相似文献
692.
K. G. Ivanov 《Geomagnetism and Aeronomy》2007,47(3):371-374
The correlation between cyclic (11-year) variations in geomagnetic activity and tropical cyclogenesis during the completed solar activity cycle (cycle 23, 1996–2006) is studied. The total number of the semidiurnal intervals, with the mean values of the planetary a p index not less than 40, for each year and the annual number of cyclones, regardless of their intensity, are used as the characteristics. The correlation coefficients r are calculated for each of the following four cyclogenesis regions: the Atlantic, northeastern and central Pacific, northwestern Pacific, and water areas of oceans and seas in the Southern Hemisphere. The conclusion that the correlation exists between magnetic storms and tropical cyclones in the Atlantic, obtained earlier by Ivanov [2006] on the basis of the data for 1996–2005, is confirmed. It has been found that the linear correlation coefficient r changed in different regions from positive to negative values: 0.55, 0, ?0.50, and ?0.50, respectively. 相似文献
693.
Lein A. Yu. Rusanov I. I. Zakharova E. E. Flint M. V. Ivanov M. V. 《Doklady Earth Sciences》2010,432(1):687-689
Within the mass of recent (unit-I) and ancient Black Sea (unit-II) sediments on the outer shelf of the Russian sector of the
Black Sea, the rates of anoxic processes participating in diagenetic transformations of carbon and sulfur compounds were first
measured using 35S and 14C radioactive tracers. The main energy source for biogeochemical processes in (unit-I) sediments is the organic matter (OM)
supplied to the bottom from the water mass. In (unit-II) sediments, this is methane in a migratory form proved by the excess
of its oxidation rate over that of its generation. In recent silt, the primary microbial process is sulfate reduction; in
unit-II, this is methane anoxic oxidation by the consortium of archeides and sulfate reductants. The organic matter produced
in methane oxidation, in turn, acts as an energy source for the community of anaerobic heterotrophic microorganisms in the
bottom sediments, which are remote from the water-sediment interface. 相似文献
694.
695.
A. S. Astakhov G. M. Kolesov O. V. Dudarev M. V. Ivanov A. N. Kolesnik 《Geochemistry International》2010,48(12):1208-1219
Abundance of noble metals (NM) and bulk chemical composition have been studied in bottom sediments of the Chukchi Sea. Distribution
of NM and their correlation with major and trace elements in the sediments have been analyzed using multicomponent statistics.
It was established that the average contents of NM in the bottom sediments of the Chukchi Sea significantly exceed those both
in shelf terrigenous sediments and stratisphere. Osmium and iridium enrich mixed and pelitic sediments relative to shallow-water
areas and their influx is presumably determined by erosion of coastal and bottom loose deposits. High Ag, Ru, Au, and Pt contents
were identified in the clayey sediments enriched in biogenic elements in the individual areas of the Southern Chukchi plain
(Chukchi sea) confined to the intersection zones of submeridional and sublatitudinal structures of the graben-rift system,
which was formed in the Mesozoic and activated in the late Cenozoic time. 相似文献
696.
Periodical surface currents with the periods of 46.5, 61, and 91 days detected from the satellite data in the Tatar Strait and Sakhalin Bay are presented as an effect of the Amur River runoff transformation in the estuary. The estuary transforms the flow as a flip-flop directing the Amur runoff by turns to the Sea of Japan or to the Sea of Okhotsk. The flip-flop period is six months. From May 23 to November 10, the Amur River flows into the Sea of Okhotsk and from November 10 to May 25, into the Sea of Japan. 相似文献
697.
We consider the use of two approaches in assessing landscape diversity of a territory: qualitative and quantitative analyses
of the landscape structure on the basis of landscape maps, and a space imagery-based calculation of landscape diversity. This
study revealed that the two approaches under consideration reflect different properties of landscape. It is established that
the various indicators used in analyzing landscape maps unveil the aspects of a complicated and multifaceted notion of “landscape
diversity”. A number of indicators overlap to a significant extent. Landscape diversity has a high degree of dependence on
an island’s area. 相似文献
698.
A. Yu. Lein P. N. Makkaveev A. S. Savvichev M. D. Kravchishina N. A. Belyaev O. M. Dara M. S. Ponyaev E. E. Zakharova A. G. Rozanov M. V. Ivanov M. V. Flint 《Oceanology》2013,53(5):570-606
The biogeochemical processes participating in the transformation of the particulate matter into sediment along the Yenisei River-St. Anna Trough (Kara Sea) meridional profile were studied using hydrochemical, geochemical, microbiological, radioisotope, and isotope methods. The water-sediment contact zone consists of three subzones: the suprabottom water, the fluffy layer, and the surface sediment. The total number, biomass, and integral activity of the microorganisms (dark 14CO2 assimilation) in the fluffy layer are usually higher than in the suprabottom water and sediment. The fluffy layer shows a decrease in the oxygen content and the growth of the dissolved biogenic elements. It was provided by the particulate organic matter supporting the vital activity of the heterotrophs from the overlying water column and by the flux of reduced compounds (NH4, H2S, CH4, Fe2+, Mn2+, and others) from the underlying sediments. The Corg isotopic composition of the fluffy layer and the sediments is 2–4 ‰ heavier than that of the particulate matter and sediment due to the presence of the isotopically heavy biomass of microorganisms. A change in the isotopic composition of the Corg in the fluffy layer and surface sediment as compared to the Corg of the particulate matter is a widespread phenomenon in the Arctic shelf seas and proves the leading role of microorganisms in the transformation of the particulate matter into sediment. 相似文献
699.
Yu. A. Izrael V. M. Zakharov N. N. Petrov A. G. Ryaboshapko V. N. Ivanov A. V. Savchenko Yu. V. Andreev Yu. A. Puzov B. G. Danelyan V. P. Kulyapin 《Russian Meteorology and Hydrology》2009,34(5):265-273
Results of a field experiment on studying solar radiation passing in the visible wavelength range are described with the model aerosol media created in the surface atmosphere. High-efficiency thermocondensation generators were used for creating model aerosol media. The index of refraction and an average size of the aerosol particles formed are close to those characteristic of the natural stratospheric aerosol. The composition and technical characteristics of the equipment complex used in the experiments to control aerosol optical and microphysical parameters and meteorological conditions of the experiment are considered. The Gaussian model of impurity dispersion in the boundary layer is used for the analysis and interpretation of measurement results. It is found that with a number concentration of aerosol particles of ~102–103 cm?3 (which corresponds to the aerosol density in the deposited layer of about 1–10 mg/m2 with the layer thickness along the ray path of about 100 m) the solar radiation attenuation with artificial aerosol layers accounts for 1 to 10%. Model estimates are in satisfactory agreement with the measurement results. 相似文献
700.
Jií Svoboda Zbigniew M. Bochenski Vra ulíkov Alena Dohnalov Srka Hladilov Martin Hloek Ivan Hor
ek Martin Ivanov Miroslav Krlík Martin Novk Alexander J.E. Pryor Sandra Szelov Rhiannon E. Stevens Jarosaw Wilczynski Piotr Wojtal 《Geoarchaeology》2011,26(6):838-866
The Dolní Věstonice–Pavlov–Milovice area (Czech Republic) on the slopes of the Pavlov Hills provides an opportunity for correlating the geomorphology of the Dyje River valley with Gravettian settlement patterns. Although the sites vary in size and complexity, they create a regular chain of strategic locations at elevations between 200 m and 240 m asl. In 2009, a road collapsed into deserted cellars inside the village of Milovice and revealed a complex of archaeological layers deep within loess, at an elevation of only 175 m asl. This paper presents an analysis of this atypical archaeological site location and compares the results with the other sites. We argue that this location allowed direct contact with mammoth herds concentrated on the floodplain, while the aquatic environment offered possibilities for gathering plants and fishing. This site represents a new aspect of organized settlement, hunting strategies, and short‐distance human movements during the Gravettian within this area. © 2011 Wiley Periodicals, Inc. 相似文献