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1.
This paper considers the possibility of aldehyde reduction by Black Sea hydrogen sulphide accompanied by the formation of nitrogen-containing organic substances The fine structure of nitrates and ammonium profiles close to the boundary of the O2/H2S zone is studied. Using data collected during Cruise 18 of the R/VProfessor Kolesnikov, it is shown that the largest ammonium concentration gradient is centred 20 m below the maximum of nitrate concentration. It has been deduced that an appreciable part of the so-called chemosynthesis production may be a result of the non-biotic synthesis with involvement of hydrogen sulphide.Translated by V. Puchkin. 相似文献
2.
V. V. Fomin 《Physical Oceanography》1995,6(5):343-350
This paper focuses on the impact of periodic internal waves on the oxygen/hydrogen sulphide co-existence zone in the open Black Sea. The numerical model is based on a set of transport/diffusion equations governing the evolution of oxygen/hydrogen sulphide concentrations and considering the reaction between them. The wave velocity field is determined by solving a spectrum problem for preinertial period internal waves, using the characteristic vertical density profile for summertime. Via analysis of the model data, the influence of wave characteristics on the parameters of the O2/H2S co-existence zone has been assessed.Translated by Vladimir A. Puchkin. 相似文献
3.
The influence of the variation of the components of the water balance on the structure of the oxygen and hydrogen sulphide fields in the Black Sea was studied on the basis of the solution of onedimensional problems for the admixture propagation. The vertical profiles of oxygen and hydrogen sulphide were calculated for the cases of enhancing or decreasing the river run-off, and when the Bosphorus undercurrent was blocked. The balance equations show that both a decreasing river run-off and blocking of the Bosphorus undercurrent result in a lowering of the boundaries of the aerobic and anaerobic zones. An increase in the river run-off results in a slight rise of these boundaries. The analysis erformed permits the formulation of some general recommendations on the prevention of an increase of the hydrogen sulphide upper boundary in the sea.Translated by Mikhail M. Trufanov. 相似文献
4.
珠江口黄茅海河口湾水动力沉积和泥沙运动的统计研究 总被引：4，自引：0，他引：4
本它根据稳健对数比主分量分析和Ｍｃｌａｒｅｎ－Ｂｏｗｅｌｓ沉积物迁移随机模型统计研究了珠江口黄茅海河口湾的水动力沉积和泥沙运动。稳健对数比主分量分析把黄茅海河口湾沉积物粒度类型划分为四大类，并相应四种不同水动力环境沉积区。Ｍｃｌａｒｅｎ－Ｂｏｗｅｌｓ随机模型在泥沙运动方向上的定量统计证实了沉积分布表明的泥沙运动规律，为今后探索和开发黄茅海河口湾海区提供新的分析依据。 相似文献
5.
Potentiometric titrations of deep Black Sea water give reasonably precise values of sulphide in the concentration range 30–300 μmol l−1 and a strong indication of thiols in the concentration range 10–30 μmol l−1. Organic analysis of Black Sea water should therefore include the search for compounds containing SH groups. A simple stoichiometric model indicates that sulphur-containing proteins might be the main source of thiols after hydrolysis and deamination. The alkalinity and total sulphide are simply related by At = 3287 ± 30 + (3.84 ± 0.10) [H2 S]t μmol kg−1. The slope of 3.84 instead of the stoichiometric slope of 2.31 indicates a lack of reduced sulphate in the form of hydrogen sulphide. 相似文献
6.
V. N. Eremeev A. M. Suvorov A. Kh. Khaliulin E. A. Godin A. A. Sizov 《Physical Oceanography》1997,8(4):293-296
On the basis of the measurements collected by MHI and other scientific institutions during expeditions in various parts of
the Black Sea and in various seasons, the variability of the upper boundary of the hydrogen sulphide zone and the respective
isopycnic surface is considered, as well as the relationship between the latter parameters and the index of atmospheric circulation.
Correlation between the studied processes in the Black Sea and atmosphere has been found to be very high.
Translated by Vladimir A. Puchkin. 相似文献
7.
Maps of the boundary topography for anaerobic waters in the Black Sea are plotted for the summers of the 1920s and 1980s. The mean depths of the H2S boundary for this period are determined. It is shown that the variation in the distribution and average location of the hydrogen sulphide zone has remained constant for the last 60 years.Translated by Mikhail M. Trufanov. 相似文献
8.
9.
E. V. Yakushev E. L. Vinogradova A. V. Dubinin A. V. Kostyleva N. M. Men’shikova S. V. Pakhomova 《Oceanology》2012,52(1):122-129
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
10.
Antonie Haas Crispin T.S. Little Heiko Sahling Gerhard Bohrmann Tobias Himmler Jörn Peckmann 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(2):283-293
Vestimentiferan tube worms are prominent members of modern methane seep communities and are totally reliant as adults on symbiotic sulphide-oxidizing bacteria for their nutrition. The sulphide is produced in the sediment by a biochemical reaction called the anaerobic oxidation of methane (AOM). A well-studied species from the Gulf of Mexico shows that seep vestimentiferans ‘mine’ sulphide from the sediment using root-like, thin walled, permeable posterior tube extensions, which can also be used to pump sulphate and possibly hydrogen ions from the soft tissue back into the sediment to increase the local rate of AOM. The ‘root-balls’ of exhumed seep vestimentiferans are intimately associated with carbonate nodules, which are a result of AOM. We have studied vestimentiferan specimens and associated carbonates from seeps at the Kouilou pockmark field on the Congo deep-sea fan and find that some of the posterior ‘root’ tubes of living specimens are enclosed with carbonate indurated sediment and other, empty examples are partially or completely replaced by the carbonate mineral aragonite. This replacement occurs from the outside of the tube wall inwards and leaves fine-scale relict textures of the original organic tube wall. The process of mineralization is unknown, but is likely a result of post-mortem microbial decay of the tube wall proteins by microorganisms or the precipitation from locally high flux of AOM derived carbonate ions. The aragonite-replaced tubes from the Kouilou pockmarks show similar features to carbonate tubes in ancient seep deposits and make it more likely that many of these fossil tubes are those of vestimentiferans. These observations have implications for the supposed origination of this group, based on molecular divergence estimates. 相似文献
11.
V. L. Vlasov B. V. Konovalov V. E. Mosharov V. N. Radchenko S. A. Khanaev D. V. Khlebnikov 《Oceanology》2010,50(1):121-130
The laboratory and marine study of photoluminescent sensors developed at the TsAGI has been conducted to create a highly sensitivity
gauge of the oxygen dissolved in seawater. The advantages of the photoluminescent gauge over the electrochemical ones are
the following: zero sensitivity to electromagnetic fields, the pH of the water, and the hydrogen sulphide and ions of heavy
metals in the water; zero oxygen consumption; and no need for the water to be pumped through the device. 相似文献
12.
《African Journal of Marine Science》2013,35(1):197-214
The major processes involved in the supply and removal of dissolved oxygen in the shelf region between 24 and 28°S are discussed in relation to the development of oxygen-deficient conditions. The area subject to this oxygen deficiency varies both seasonally and geographically. It is suggested that both the shallow distribution of rock lobster in this part of the Benguela Current system and the periodically low catch per unit effort may be related to the onset of oxygen deficiency. Preliminary laboratory findings indicate that avoidance of oxygen-deficient areas by rock lobster might not be caused solely by the lack of oxygen per se, but by the co-existence at low oxygen concentrations of toxic reduced compounds such as hydrogen sulphide. 相似文献
13.
The products of 35S-sulphate reduction by sedimentary bacteria were measured at two sites in a salt marsh on the east coast of England. Non-acid-volatile products were measured, after acid-volatile sulphide was removed, by their reduction to sulphide by digestion with tin. The proportion of the sulphate reduced to tin-reducible products varied between 25% in a salt marsh pan and 61% in creek sediment, over a 0–25 cm depth profile. There were also variations with depth at each site in the proportions of sulphate reduced to tin-reducible products. Further examination revealed differences in the proportions of sulphate which were reduced to free sulphide, acid-volatile sulphide, sulphur or pyrite at the two sites. The data suggest that previous work which did not measure non-acid-volatile products underestimated sulphate reduction rates by three-fold in the creek site, but by only one third in the pan. 相似文献
14.
Rare earth element geochemistry in cold-seep pore waters of Hydrate Ridge, northeast Pacific Ocean 总被引：2，自引：1，他引：1
Tobias Himmler Brian A. Haley Marta E. Torres Gary P. Klinkhammer Gerhard Bohrmann Jörn Peckmann 《Geo-Marine Letters》2013,33(5):369-379
The concentrations of rare earth elements (REEs), sulphate, hydrogen sulphide, total alkalinity, calcium, magnesium and phosphate were measured in shallow (<12 cm below seafloor) pore waters from cold-seep sediments on the northern and southern summits of Hydrate Ridge, offshore Oregon. Downward-decreasing sulphate and coevally increasing sulphide concentrations reveal sulphate reduction as dominant early diagenetic process from ~2 cm depth downwards. A strong increase of total dissolved REE (∑REE) concentrations is evident immediately below the sediment–water interface, which can be related to early diagenetic release of REEs into pore water resulting from the re-mineralization of particulate organic matter. The highest pore water ∑REE concentrations were measured close to the sediment–water interface at ~2 cm depth. Distinct shale-normalized REE patterns point to particulate organic matter and iron oxides as main REE sources in the upper ~2-cm depth interval. In general, the pore waters have shale-normalized patterns reflecting heavy REE (HREE) enrichment, which suggests preferential complexation of HREEs with carbonate ions. Below ~2 cm depth, a downward decrease in ∑REE correlates with a decrease in pore water calcium concentrations. At this depth, the anaerobic oxidation of methane (AOM) coupled to sulphate reduction increases carbonate alkalinity through the production of bicarbonate, which results in the precipitation of carbonate minerals. It seems therefore likely that the REEs and calcium are consumed during vast AOM-induced precipitation of carbonate in shallow Hydrate Ridge sediments. The analysis of pore waters from Hydrate Ridge shed new light on early diagenetic processes at cold seeps, corroborating the great potential of REEs to identify geochemical processes and to constrain environmental conditions. 相似文献
15.
《Marine Geology》1999,153(1-4):199-219
Pyrite formation within and directly below sapropels in the eastern Mediterranean was governed by the relative rates of sulphide production and Fe liberation and supply to the organic-rich layers. At times of relatively high SO2−4 reduction, sulphide could diffuse downward from the sapropel and formed pyrite in underlying sediments. The sources of Fe for pyrite formation comprised detrital Fe and diagenetically liberated Fe(II) from sapropel-underlying sediments. In organic-rich sapropels, input of Fe from the water column via Fe sulphide formation in the water may have been important as well. Rapid pyrite formation at high saturation levels resulted in the formation of framboidal pyrite within the sapropels, whereas below the sapropels slow euhedral pyrite formation at low saturation levels occurred. δ34S values of pyrite are −33‰ to −50‰. Below the sapropels δ34S is lower than within the sapropels, as a result of increased sulphide re-oxidation at times of relatively high sulphide production and concentration when sulphide could escape from the sediment. The percentage of initially formed sulphide that was re-oxidized was estimated from organic carbon fluxes and burial efficiencies in the sediment. It ranges from 34% to 80%, varying significantly between sapropels. Increased palaeoproductivity as well as enhanced preservation contributed to magnified accumulation of organic matter in sapropels. 相似文献
16.
A major substratum for vent organisms on Juan de Fuca and Explorer Ridges of the northeast Pacific is the polymetallic sulphide chimney. The deposition processes and subsequent growth of such chimneys provide a dynamic and extreme habitat that changes rapidly. During initial venting stages, colonization must await stabilization of the chimney structure. As the porous anhydrite shell accumulates sulphide minerals, protection from direct hot water contact increases for organisms colonizing the outer walls while sufficient vent water still diffuses for the support of chemosynthesis. Vestimentiferan worms are found on small sulphide mounds but the active growth and collapse of anhydrite spires is a major source of disruption and mortality. High temperature venting and spire growth appear to attract alvinellid polychaetes which may be implicated in the process of strengthening and sealing the anhydrite spires. Fauna on the growing chimney is subject to changes in fluid flow patterns that can make the structure uninhabitable. Large chimneys are inhabited by more species indicating that a diversification of habitat results from variations in mineralization and fluid availability. Chimney fauna has become specialized in exploiting an unpredictable and unstable habitat in an extreme example of the control of biotic development by the physical environment. 相似文献
17.
《Deep Sea Research Part I: Oceanographic Research Papers》2003,50(6):737-747
To improve our understanding of the environmental constraints exerted on vent fauna, we investigated sulphide chemistry in the habitats of Riftia pachyptila and Alvinella pompejana, at the Genesis and Elsa EPR 13°N sites. Temperature, pH and sulphide measurement series were acquired in situ, around the organisms, from the submersible Nautile. Hot fluid samples were also collected to evaluate end-member composition at these sites. Under the assumption of conservative mixing, pH, total sulphide concentration and sulphide speciation gradients in relation to temperature were modelled. From the comparison of measured and calculated concentrations, deviation from conservative behaviour was highlighted for total sulphide versus temperature. While the observed sulphide depletion around tubeworms suggests significant subsurface removal or biological consumption, the apparent sulphide enrichment in the alvinellid environment may reveal either conductive cooling of diffusing fluids or a secondary sulphide source. The calculated sulphide speciation appears to be contrasted at the two sites studied. Because of the low iron content in Genesis fluid, iron sulphide would not constitute a dominant sulphide species and the toxic H2S form would be predominant in the mixing zone. By contrast, iron is expected to play a dominant role in sulphide speciation at the Elsa site where the end-member is iron rich. With respect to sulphide, the conditions encountered in the different habitats considered in this study are strongly contrasted. A low fluid flux was observed in the R. pachyptila habitat, contrasting with previous ideas, and suggests that sulphide availability could be a major limiting factor. Particularly, the bioavailable HS− form is expected to vary weakly along the mixing gradient. In contrast, sulphide in the A. pompejana environment is shown to be particularly high, about one order of magnitude higher than observed for other Eastern Pacific alvinellids. At Genesis, because of the acidic pH and low iron conditions encountered, exposure to high levels of toxic sulphide is expected. A. pompejana thus appears to be particularly tolerant to such toxic conditions, but, as previously suggested, less severe conditions may also be found when iron is rich enough in the medium to dominate sulphide chemistry. 相似文献
18.
The distributions of dissolved and solid phase Fe and Mn have been variously determined in vertical profiles through the water column and sediments at three stations in Bolstadfjord, S.W. Norway. Elevated concentrations of dissolved and suspended particulate Fe and Mn are associated with restricted deep waters as a result of redox reactions and with river discharge. The basin sediments are anoxic throughout but because of the greatly restricted circulation, remobilized Fe and Mn appear to remain predominantly trapped within the fjord. Differentiation of Fe and Mn occurs to the extent that Fe sulphide precipitation is ubiquitous in the sediments whereas the entrapment of Mn, probably through Mn carbonate precipitation, is found only in the sediments of the more seaward basin (maximum Mn content of 1·5% by weight). 相似文献
19.
20.
A set of parameters is considered which allow us to determine the morphological structure of the vertical temperature, salinity, and density fields. If the parameters are integrated over the layer chosen, their computing does not call for imposing conditions of the fluctuation components' statistical heterogeneity. The parameters can be applied to describe both fine structure stratification and background stratification. Presumably, they may be used for mapping diverse types of thermohaline water stratification and the vertical structure of other fields when large sets of data covering the areas with marked spatial variability of the relevant conditions are available. Examples of simulations andin situ calculations are provided.Translated by Vladimir A. Puchkin. 相似文献