Nadezhda Politova

Early diagenesis in recent bottom sediments of the Dvina Bay (White Sea)

Investigations in the water column and bottom sediments including entrapped water were carried out on expeditions of the P.P. Shirshov Institute of Oceanology in the Dvina Bay, the White Sea. We studied the transformation of particulate organic matter at the biogeochemical barrier between the water and bottom and in the underlying Holocene sediments. Low rates of the early diagenesis of sediments caused by low values of primary production in the conditions of high fluxes of terrigenous organic matter were established. The low temperatures of microorganisms habitat play the secondary role.

The Composition of the Coarse Fraction of Aerosols in the Marine Boundary Layer over the Laptev, Kara and Barents Seas

During the 49-th cruise of R/V Dmitry Mendeleev in August-October 1993 and PFS Polarstern cruise ARK XI/1 in July-September 1995, 22 samples of aerosols were collected in the Laptev, Kara and Barents Seas. Aerosols were studied for particle size, morphology, and composition. New results of this work are presented in this paper. The average size of particles in samples collected by meshes in different areas differ insignificantly (4.18 to 5.54 μm). In most samples mineral particles and organic matter (fibers of vegetation, pollens, diatoms) were the main components, organic carbon content was 17.6% in average. The individual anthropogenic combustion spheres with diameter from 1 to 10 μm mostly consist of: (1) Si, Al, K, and Fe in the South-Western Laptev Sea; (2) Si, Al, Fe, and K in the Central Kara Sea; (3) Fe, Ni, and Si in the Southern Kara Sea, and (4) Si, Al, Fe, and Ni in the Southern Barents Sea.

Multidisciplinary Research in the Barents Sea on Cruise 67 of the R/V Akademik Mstislav Keldysh

From August 25 through October 10, 2016, cruise 67 of the V/R Akademik Mstislav Keldysh from the port of Arkhangelsk to the port of Kaliningrad was carried out. The aim of the expedition was multidisciplinary study of the Barents Sea system; therefore, the following main tasks were posed: study of aerosols over the sea surface; study of the hydrological and hydrochemical structure of water; collection of materials for subsequent analysis of the mineral, chemical, and isotopic composition of microparticles and quantitative estimation of disperse sediment ary matter f luxes in the water column, including rock-forming chemical elements, carbon (organic and carbonaceous), toxic heavy metals, and hydrocarbons; study of features of the vertical particle f luxes; microbiological, biogeochemical, isotopic-geochemical, and molecular-biological investigations of near-bottom water and bottom sediments; estimation of the current state of Barents Sea ecological systems and analysis of their variability under the influence of present-day climate change and anthropogenic impact, including solid radioactive waste dumping and contamination by anthropogenic hydrocarbons; and lithogeochemical and high-resolution paleoceanographic and paleoclimatic investigations. The expedition also provided educational and internship work experience for students, graduates, and postgraduates of the Institute of Oceanology of the Russian Academy of Sciences and Moscow State University. The expedition took place in the Barents Sea area (in the Russian and Norwegian economic zones and in Russian territorial waters) (see Fig. 1). In total, 52 stations were done. From the port of Arkhangelsk to the port of Kaliningrad, 7675 nautical miles (NM) were covered. Throughout the cruise, atmospheric observations were carried out. In addition to standard meteorological data, the aerosol particle concentrations in several size ranges were measured, aerosols were collected with nylon meshes, the optical thickness of the atmosphere and the weight concentration of soot were measured, air was filtered to collect black carbon, and to study the ion and element composition of the atmosphere. Among the interesting results obtained by the expedition was the noteworthy increase in atmospheric turbidity at the beginning of September in the Barents Sea area, caused by the long-range transport of fine smoke aerosol originating from forest fires in Siberia.

Suspended Particulate Matter as a Main Source and Proxy of the Sedimentation Processes

The material for our study was collected in the White Sea during 22 interdisciplinary expeditions organized by the Shirshov Institute of Oceanology, Russian Academy of Sciences (IO RAS), in 2000–2014. The researches were carried out mostly in June–August; however we have some samples for autumn–winter and early spring seasons. Here, we report the concentration of suspended particulate matter (SPM), its composition and properties, as well as their changes due to natural zoning and local conditions. This paper discusses the features in the distribution of SPM concentration, grain-size, mineral, and major phase composition. As far as possible, we involved our own and other published data on hydrology, bottom morphology, and particulate and dissolved river runoff from the catchment area, abundance and composition of marine phyto- and bacterioplankton. This new knowledge has been used to describe particles dispersion system of the White Sea, which forms a giant reservoir of micro- and nanoparticles, using terms adopted in sedimentology and oceanography.

Vertical Fluxes of Suspended Sedimentary Matter in Arctic Sedimentogenesis of Intracontinental Seas

Based on long-term studies of a small sea in the Arctic Ocean, new regularities in the sedimentary process under the conditions of Arctic sedimentogenesis were established. The quantitative transition of particulate sedimentary materials into the concentrated forms (bottom sediments) in the White Sea follows the linear dependence with a local maximum in the deep nepheloid layer. Marginal filters (Severnaya Dvina River, etc.), which are areas of ultrarapid sedimentation, were distinguished. The long-term data on the concentration of suspension and fluxes of particulate sedimentary material clearly indicate stable annual nepheloid layers, i.e., the distribution of particulate forms of sedimentary material (suspension) in the water column proceeds by new regularities, which may be distinguished ever more clearly.

Geological studies of the Northern Atlantic during the 49th cruise of the R/V Akademik Ioffe

A. A. Klyuvitkina, *, N. V. Politovaa, A. N. Novigatskya, E. A. Novichkovaa, A. S. Savvichevb, N. V. Kozinaa, L. D. Bashirovac, A. K. Ambrosimova, D. F. Budkoa, and S. M. Isachenkoc aShirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia bWinogradskiy Institute of Microbiology, Federal Research Center Fundamentals of Biotechnology, Russian Academy of Sciences, Moscow, Russia cAtlantic Branch, Shirshov Institute of Oceanology, Russian Academy of Sciences, Kaliningrad, Russia *e-mail: klyuvitkin@ocean.ru Received November 19, 2015