This paper analyses the data on the distribution of mercury in the surface layer of bottom sediments (0–5 cm) obtained in
course of sampling trips within the mouth region of the Severnaya Dvina River and the White Sea area. A total of 170 analyses
for mercury were performed. Such wide-scale determination of the mercury content in the bottom sediments was carried out for
the first time in the study region. The patterns of mercury distribution in the Severnaya Dvina River-White Sea transect are
revealed and described. It is shown that the marginal filter of the Severnaya Dvina River facilitates cosedimentation of the
main portion of anthropogenic mercury with suspended matter. This drastically decreases the risk of penetration of mercury
to the White Sea waters and partially (with the gravity current) to the Barents Sea waters. In general, the Severnaya Dvina
River is characterized by mercury pollution of a local scale within the urban territories. No regional pollution of the White
Sea off the marginal filter was revealed. 相似文献
Along the transatlantic section from Ushuaia to Gdańsk (March 26–May 7, 2015; cruise 47 of R/V Akademik Ioffe), data were obtained on the concentrations of aerosols in the near-water layer of the atmosphere and of particulate matter in surface waters, as well as of organic compounds within the considered matter (Corg, chlorophyll a, lipids, and hydrocarbons). The concentrations of aerosols amounted to 1237–111 739 particles/L for the fraction of 0.3–1 μm and to 0.02–34.4 μg/m2/day for the matter collected by means of the network procedure. The distribution of aerosols is affected by circumcontinental zoning and by the fluxes from arid areas of African deserts. The maximum concentration of the treated compounds were found in the river–sea frontal area (the runoff of the Colorado River, Argentina), as well as when nearing the coasts, especially in the English Channel. 相似文献
Data on the mineral composition of sedimentary matter and its fluxes in the sediment system of the Caspian Sea are presented. River runoff, aerosols, particulate matter from sediment traps, and the upper layer (0–1 cm) of bottom sediments are considered. The contents of detrital minerals (quartz, albite, and K-feldspar), clay minerals (illite, chlorite, and kaolinite), and carbonates (calcite, Mg-calcite, dolomite, aragonite, and rhodochrosite) are determined. Gypsum was found in bottom sediments but is absent in the other object of the sediment system. 相似文献
Studies of lakes at different stages of separation from the sea have been carried out on the northwestern coast of Kandalaksha Gulf of the White Sea. At the end of the winter period, from March 16 to 29, 2013, the lakes Kislo–Sladkoe, Trekhtzvetnoe, Nizhnee Ershovskoe, Ermolinskaya Bay and snow near the pier of Pertsov White Sea Biological Station of Moscow State University (WSBS MSU) were studied. The isotope characteristics of the water of lakes, ice and snow, the distribution of salinity, temperature, and hydrogen sulfide content were studied.
The contribution of different geochemical processes in the accumulation of metals in dispersed sedimentary matter collected by ADOO was estimated for the first time for the White Sea system. The contents of Al, Fe, Cr, Ni, Со, and Мо (from 60 to 90% of the total content) are mainly controlled by terrigenous processes. The group of geochemically mobile elements includes Mn, Cu, Pb, and Cd; the sum of their forms 1–3, which include the contribution of absorption−desorption and formation of authigenic hydroxides and organic compounds, accounts for, on average, from 52 to 83 Mn %. With increasing water depth, the fraction of the lithogenic form remains either constant or increases insignificantly. In contrast, Mn shows a sharp increase in geochemically mobile forms, heavy metals (Pb, Cu, Mo, Co, and Cd) of which are associated with.
The descent of a large quantity of dust responsible for bright colors of atmospheric precipitation in the temperate, subpolar, and polar zones of the northern hemisphere is rarely observed [1–5]. In the twentieth century and in the beginning of the twenty-first century in the northern part of European Russia, such events had not been registered right up to March 25–26, 2008. At that time in some parts of the Arkhangelsk region, Komi Republic, and Nenets Autonomous Area, atmospheric precipitation as moist snow and rain responsible for sand and saffron colors of ice crust formation on the snow surface was observed. Thus, due to detailed mineralogical, geochemical, pollen, diatom, and meteorological investigations, it was established that the main source of the yellow dust is the semidesert and steppe regions of the Northwest Kazakhstan, and the Volgograd and Astrakhan regions, Kalmykia. 相似文献
Research on sedimentogenesis and geochemistry of the Arctic Ocean over the last 10–20 years has allowed direct (in situ) studies to be made for all types of sedimentary matter that mix together and form the bottom deposit. Contrary to common knowledge, river sediment turned out to be insignificant; instead, more important is the dispersed sedimentary matter (suspension) from the atmosphere, cryosphere (snow, ice), marine water, riverine water, biosphere (plankton and benthos), and anthroposphere (all types of pollutants), supplemented by the endogenic mater supplied from spreading zone of the Gakkel Ridge. The mixture is dominated by sedimentary material discharged from sea ice; hence, this type of sedimentogenesis is referred to as the ice-rafted marine sedimentogenesis.Application of new methods and tools (including satellites, remote hydrooptical, hydrophysical, and hydroacoustic survey, etc.) and in situ analyses produced measurements of content, composition, and characteristics of all types of dispersed sedimentary matter, its fluxes (mg/m2/year), vectors of movement, and rates for different segments of the Arctic Ocean; observations were carried out continuously on different time scale, from hours–days to seasons and dozens of years. It is a new approach to the study of sedimentary matter that opens up new possibility for a 4D quantitative sedimentology. 相似文献
The first results of studies of vertical fluxes of sediment particles using the sediment traps at the Trans-Caspian section are presented. The flux values and distribution regularities are established. The fluxes of particles forming the sediment are also determined. The intra-annual variability in the fluxes corresponds to the seasonal variability of the biological activity. Above the northern slope of the Derbent Basin, the maximum vertical fluxes are recorded in the winter, which is caused by the intensification of the near-bottom currents. 相似文献