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1.
Resulting from the surveys in the Blagopoluchiya and Techenii bays at the Novaya Zemlya Archipelago during cruise 54 of the R/V Akademik Mstislav Keldysh in September of 2007, it was shown that the waters supplied from the archipelago coasts contained considerable amounts of dissolved nitrogen and phosphorus. The pH values and total alkalinities were also considerably increased. The laboratory experiments confirmed that the rocks forming the coasts of the surveyed bays might be sources of nitrogen and phosphorus. The effect of the Novaya Zemlya runoff upon the hydrochemical structure of the upper 10-m layer of the seawaters was traced for 16–20 km from the coast during the period of the surveys. 相似文献
2.
Hydrochemical studies of the Kara Sea were included into the program of the integrated expedition during cruise 54 of the
R/V Akademik Mstislav Keldysh (September 9–30, 2007). In several sea areas quite different in their weather conditions, a large set of hydrochemical analyses
was carried out, including the determination of the primary nutrients (silicon and different forms of nitrogen and phosphorus),
the dissolved oxygen content, and the total alkalinity and pH values. The report presents the hydrochemical conditions in
the southwestern part of the Kara Sea and the most striking results from the authors’ viewpoint. The data were compared to
those of the integrated oceanographic expedition of cruise 49 of the R/V Dmitry Mendeleev in 1993. 相似文献
3.
The accuracy and detection limit of the oxygen technique is an actual problem in studying the processes that occur in the
redox zone. The formal accuracy of the Winkler technique is 1 μM (0.02 mL L −1) and its detection limit is about 3.0 μM (0.06 mL L −1). These values are significantly higher than the similar characteristics (in molar concentrations) for such parameters as
the hydrogen sulphide, nitrates, manganese, and others. In this work, we describe some recommendations for increasing the
accuracy of the Winkler technique. The results of the application of these recommendations for the suboxic zone of the Black
Sea are presented. During the 100th cruise of the R/V Professor Shtokman, argon-filled balloons were attached to the upper valves of Niskin bottles during the sampling, which allowed protecting
the samples from contamination with atmospheric oxygen. The titration was performed with an automatic Metrohm Titrino burette
with potentiometric end point detection. That allowed us to significantly increase the accuracy and decrease the detection
limit compared with the visual techniques. The oxidized forms of metals present in the sea water (Mn(IV), Mn(III); Fe(III))
were measured, which allowed us to correct the Winkler technique calculations for the oxidizers. The studies performed during
the 100th cruise of the R/V Professor Shtokman confirmed the absence of a layer of the coexistence of oxygen and hydrogen sulphide. 相似文献
5.
The optical properties and distribution of dissolved organic matter in the surface waters of the Kara Sea and bays of Novaya Zemlya archipelago were studied during the 63th cruise of the R/V Akademik Mstislav Keldysh. The fluorescence of dissolved organic matter has been studied over wide excitation (230–550 nm) and emission (240–650 nm) wavelength ranges. Based on the results of fluorescence measurements, we propose a simple technique for estimating the relative content of humic compounds entering the Kara Sea shelf region with Ob and Yenisei river runoff. We have found that the blue shift parameters of the DOM fluorescence are Δ 270–310 = 28 ± 2 nm and Δ 355–310 = 29 ± 2 nm. The highest contents of humic compounds in surface waters were measured on the transect across the desalinated layer of the Kara Sea, near the continental slope on the transect along the St. Anna Trough, and in the area of Sedova, Oga and Tsivol’ki bays. Traces of labile terrigenous organic matter were found in the region of the Voronin Trough, in the bays of the Severny Island of Novaya Zemlya, as well as in some freshwater reservoirs and ice samples of the archipelago. We established a conservative distribution of dissolved organic matter, whose content in water varied from 1.25 to 8.55 mg/L. 相似文献
6.
The first thorough analysis of microfossils from ore-bearing sediments of the Ashadze-1 hydrothermal field in the Mid-Atlantic
Ridge sampled during cruise 26 of the R/V Professor Logachev in 2005 revealed the substantial influence of hydrothermal processes on the preservation of planktonic calcareous organisms,
as well as on the preservation and composition of the benthic foraminifers. From the lateral and vertical distribution patterns
and the secondary alterations of the microfossils, it is inferred that the main phase of the hydrothermal mineralization occurred
in the Holocene. Heavy metals (Cu, Co, Cr, and Ag) were accumulated by foraminiferal tests and in their enveloping Fe-Mn crusts.
The distribution of authigenic minerals replacing foraminiferal tests demonstrates local zoning related to the hydrothermal
activity. There are three mineral-geochemical zones defined: the sulfide zone, the zone with an elevated Mg content, and zone
of Fe-Mn crusts. 相似文献
7.
Cruise 81 of the R/V Akademik Mstislav Keldysh was organized by Shirshov Institute of Oceanology and took place from August 27 to September 25, 2020 under the Program “Marine Ecosystems of the Siberian Arctic.” Participants included 76 scientists from the institutes of Russian Academy of Sciences, Moscow State University, VNIRO, and the NRC Kurchatov Institute and specialists from the Emergency Situations Ministry. Coordinated hydrophysical, hydrochemical, biooceanological, geochemical, and radioecological research was carried out over the Kara Sea, on the shelf near the St. Anna Trough, the continental slope, the Novaya Zemlya depression, and bays of the eastern coast of Novaya Zemlya. The condition of disposed radioactive waste in bays of the archipelago was assessed. 相似文献
8.
The objectives of cruise 41 of R/V Akademik Vernadsky and the data provided on the RAZREZY project are reported.Translated by V. Puchkin. 相似文献
9.
Calcareous nannoplankton from sediment trap samples collected at six sites in the Atlantic Ocean from 23° S to 73° N (cruise 20 of R/V Vityaz’ and cruise 33 and 34 of R/V Akademik Mstislav Keldysh). Those samples were studied with a scanning electron microscope. In the coastal and open-sea regions of the North and South Atlantic and in the subarctic region of the Norwegian Sea, the conditions are significantly different. In the shelf area of the Benguela upwelling, 11 species were recognized; some of them were agglutinated by diatoms and tintinnides or covered the surface of pellets. The Broken Spur and TAG pelagic areas of the North Atlantic contained up to 43 coccolith species. They included holococcoliths, large pelagic, and delicate easily soluble species distributed over the entire water column. The presence of coccoliths in the high-latitude area of the Norwegian Sea is related to their supply with the warmer North Atlantic waters. These assemblages are distinguished by a low species diversity and an enhancement of the coccolith solubility with the depth increase. 相似文献
10.
The first multichannel seismic reflection measurements of the north-east Greenland shelf north of 79°N were made as part of the R.V. Polarstern cruise ARK V/1988. This area is perennially covered by sea ice. The sparse seismic data show a very deep rift basin filled with up to 10 km of high velocity rocks interpreted as Carboniferous and Permian sediments. Conspicuous structures interpreted as marginal reefs are associated with the western flank of the rift basin. 相似文献
11.
To evaluate the structure and photosynthetic activity of the phytoplankton of the northwestern part of the Sea of Japan, the
results of the surveys conducted from February 26 to March 9, 2003, during the 30th cruise of the R/V Akademik Lavrentyev were used. The species composition was considered taking into account the influences of the hydrological conditions. In particular,
the studied water area was divided into four zones with various sizes of the mixed layer depth (MLD). An inverse relationship
between the MLD and the content of chlorophyll a (Chl a) in various zones was established. The diatom algae were the basic dominants of the composite structure of the phytoplankton
everywhere. It is revealed that, at a MLD increase, smaller forms of microalgae receive development. The intrapopulation relations
are caused by the adaptation of various species of phytoplankton to the influence of external factors, among which the size
of MLD is fundamental. 相似文献
12.
A bottom station (lander) was installed onto the bottom at station 6214 during cruise 86 of R/V Professor Shtokman. Resulting from this installation, all the systems of the lander functioned within the predicted regimen. The potentialities
of the chamber experiment technique (the lander) seem to be preferable compared to those of the studies by means of the method
of interstitial waters, especially for the elements of variable valence. 相似文献
13.
The composition and distribution of the macrobenthic communities in the Ob estuary and the adjacent Kara Sea shelf were studied
during the 54th cruise of the R/V Akademik Mstislav Keldysh. With the transition from the Ob River’s mouth to the open parts of the sea, the gradual changes of the bottom biocenoses
included changes in the leading taxa. Along with the increase in the salinity, the freshwater and brackish water taxa are
replaced by related forms adapted to dwelling in seawater. The comparison of the original data with the results of the previous
investigations revealed considerable spatial and temporal variations of the bottom communities in the studied area. The main
environmental factors determining the fauna distribution in the estuarine zone are discussed. The extensive biocenosis dominated
by Portlandia aestuariorum in the Ob estuary was found for the first time. 相似文献
14.
During the 50th cruise of R/V Akademik Mstislav Keldysh, on the south slope of the Atlantis massif (30°07′N; the Middle Atlantic Ridge), an inactive hydrothermal field named the
Lost Village was discovered. This new field was formed of light carbonate rock and was located near the active Lost City hydrothermal
field. The mineralogical associations of these fields were studied. A conclusion about the participation the ocean water in
the changing of the carbonate composition of the inactive hydrothermal field was reached. 相似文献
15.
By the data of cruise 54 of the R/V Akademik Mstislav Keldysh (September 2007), the results of geochemical studies of the redox processes in the bottom sediments of the Ob River’s near-mouth
area as applied to the redox indicator elements such as manganese, iron, and sulfur are presented. The characteristics of
the bottom sediments and the distribution of these elements in them testify not only to the significant role of the mixing
processes in the formation of the geochemical profile of the bottom sediments in the estuary but also to the role of the postsedimentation
(diagenetic) processes. 相似文献
16.
Forty-two mesozooplankton samples were collected in the Barents Sea during the cruise of the R/V Dal’nie Zelentsy in August 2006. In total, 72 taxa of planktic animals were found. The minimal average mesozooplankton abundance was noted
in the Murmansk coastal waters in the south of the sea (154 ind./m 3), while the maximal was noted in the Arctic waters (1533 ind./m 3). The average wet biomass varied from 32 to 830 mg/m 3. The zooplankton abundance and biomass exceeded the relevant average long-term parameters by 1.5–2 times and by 1.2–1.4 times,
respectively. The mean biodiversity (Shannon’s index) of the zooplankton communities was low: H′ = 1.62 ± 0.104 bit/ind. 相似文献
17.
Oceanology - During cruise 73 of the R/V Professor Gagarinskiy and cruise 53 of the R/V Akademik Oparin, oceanographic studies of the Sea of Japan and Sea of Okhotsk and the Northwest Pacific were... 相似文献
18.
Using a flow cytometer (FCM) onboard the R/V Xuelong during the 24th Chinese Antarctic cruise, picoplankton community structure and biomass in the surface water were examined along the latitude and around the Antarctic Ocean. Salinity and temperature were automatically recorded and total Chla was determined. Along the cruise, the abundance of Synechococcus, Prochlorococcus, pico-eukaryotes and heterotrophic bacteria ranged in 0.001-1.855×10 8 ind./L, 0.000-2.778£108 ind./L, 0.002-1.060×10 8 ind./L and 0.132-27.073×10 8 ind./L, respectively. Major oceanic distribution of Synechococcus and Prochlorococcus appeared between latitudes 30°N and 30°S. Prochlorococcus was mainly influenced by water temperature, water mass combination and freshwater inflow. Meanwhile, Synechococcus distribution was significantly associated with landing freshwater inflow. Pico-eukaryotes and heterotrophic bacteria were distributed all over the oceans, but with a relatively low abundance in the high latitudes of the Antarctic Ocean. Principal Component Analysis showed that at same latitude of Atlantic Ocean and Indian Ocean, picoplankton distribution and constitution were totally different, geographical location and different water masses combination would be main reasons. 相似文献
19.
Three dives of Mir manned submersibles with plankton counts and two vertical plankton hauls with a BR net were carried out above the Lost City (Atlantis underwater massif) and the Broken Spur hydrothermal fields during cruise 50 of R/V Akademik Mstislav Keldysh. Above the Atlantis seamount, no significant increase in the plankton concentration was found. Above the Lost City field, the horizontal heterogeneity of the plankton distribution in the near-bottom layer and in the overlying water layers was shown. The near-bottom aggregations of euphausiids and amphipods previously reported by other scientists seem to be related to the attraction of the animals by the submersible’s headlights rather than represent a natural phenomenon. 相似文献
20.
During cruise 73-A-3 of the R/V “Alaminos”, seawater samples from the nepheloid layer and overlying water were collected and filtered through 0.4 μm Millipore ® Ultra Thin filters for microscopic analysis with a Jeol JSM-U3 scanning electron microscope. The results of the studies of the suspended matter with the scanning electron microscope indicate that there is a significant increase in the percentage of the total number of particles that are associated as aggregates for the nepheloid layer relative to the overlying water. This suggests that once nepheloid layers are formed, they might represent regions of high sedimentation due to aggregate formation. 相似文献
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