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Maslov A. V. Kuznetsov A. B. Politova N. V. Kozina N. V. Novigatsky A. N. Shevchenko V. P. 《Doklady Earth Sciences》2019,485(1):268-272
Doklady Earth Sciences - The isotopic characteristics (εNd, 207Pb/206Pb, and 87Sr/86Sr) of the modern bottom sediments sampled in the Barents Sea during the 67th voyage of the R/V Akademik... 相似文献
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Lukashin V. N. Kravchishina M. D. Klyuvitkin A. A. Novigatsky A. N. Politova N. V. 《Oceanology》2019,59(3):381-391
Oceanology - The first data on a long-term study of the Volga River marginal filter are reported. The concentrations of suspended particulate matter, particulate chemical elements, and trace... 相似文献
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Radchenko I. G. Ilyash L. V. Shevchenko V. P. Zdorovennov R. E. Novigatsky A. N. Politova N. V. Tolstikov A. V. 《Oceanology》2019,59(3):305-315
Oceanology - The species composition and biomass of phytoplankton, as well as hydrological characteristics, were estimated during four spatial surveys in the Subarctic tidal Kem’ River... 相似文献
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Novichkova E. A. Savvichev A. S. Bashirova L. D. Kozina N. V. Klyuvitkin A. A. Politova N. V. Novigatsky A. N. Lein A. Yu. 《Oceanology》2019,59(4):577-590
Oceanology - Marine sediments and samples of suspended particulate matter from the North Atlantic were studied. It is shown that modern sedimentation in this area is controlled mainly by the... 相似文献
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A. Yu. Lein M. D. Kravchishina N. V. Politova A. S. Savvichev E. F. Veslopolova I. N. Mitskevich N. V. Ul’yanova V. P. Shevchenko M. V. Ivanov 《Lithology and Mineral Resources》2012,47(2):99-128
Complex biogeochemical studies including the determination of isotopic composition of Corg in both suspended particulate matter and surface horizon (0–1 cm) of sediments (more than 260 determinations of δ13C-Corg) were carried out for five Arctic shelf seas: White, Barents, Kara, East Siberian, and Chukchi. The aim of this study is
to elucidate causes that change the isotopic composition of particulate organic carbon at the water-sediment boundary. It
is shown that the isotopic composition of Corg in sediments from seas with a high river runoff (White, Kara, and East Siberian) does not inherit the isotopic composition
of Corg in particles precipitating from the water column, but is enriched in heavy 13C. Seas with a low river runoff (Barents and Chukchi) show insignificant difference between the value of δ13C-Corg in both suspended load and sediment because of a low content of the isotopically light allochthonous organic matter (OM)
in particulates. Complex biogeochemical studies with radioisotope tracers (14CO2, 35S, and 14CH4) revealed the existence of specific microbial filter formed from heterotrophic and autotrophic organisms at the water-sediment
boundary. This filter prevents the mass influx of products of OM decomposition into water column, as well as reduces the influx
of a part of OM contained in the suspended particulate matter from water into sediment. 相似文献
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M. D. Kravchishina A. Yu. Lein L. A. Pautova A. A. Klyuvitkin N. V. Politova A. N. Novigatsky V. A. Silkin 《Oceanology》2016,56(6):819-836
The features of the vertical distribution of chlorophyll a, particulate organic carbon and its isotopic composition, total suspended particulate matter (SPM), and the structure of the phytoplankton community in the Middle and South Caspian Sea in May–June 2012 are discussed. The subsurface chlorophyll a maximum (SCM) was found everywhere at depths of ~20 to 40–60 m. The position of this layer is confined to the depth of the seasonal thermocline, which is determined by the development of a cold-water (dark) phytocenosis. The genesis of this layer was studied. The increase in chlorophyll a concentration in this layer is caused by an abundance of phytoplankton or an increased concentration of this phytopigments per algal cell. The highest values of the studied organic compounds and phytoplankton biomass are revealed as close to the seasonal thermocline extending from the southern periphery of the Derbent Depression to the Apsheron Sill, which is determined by the bottom topography. The presence of chlorophyll a at depths exceeding 300 m (up to ≥1 mg/m3) was revealed. This was supported by findings of individual algal cells containing chlorophyll a and even their accumulations in the deep water layer. The most probable mechanisms responsible for the presence of these cells at the deep water level are discussed in the paper. The vertical distribution of the values of the organic carbon isotopic composition is primarily controlled by the vertical structure of phytoplankton and chlorophyll a in the water column up to ~500 m and by biogeochemical processes at the redox barrier (~600 m layer). The relative stability of chlorophyll a and the stability of pheophytin a in anaerobic environments were verified. A significant amount of weakly transformed chlorophyll a was found close the sea bottom. 相似文献
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