Resumption of hydrogen sulfide contamination of the water column of deep basins in the Caspian Sea

2013 ◽  
Vol 453 (1) ◽  
pp. 1094-1099 ◽  
Author(s):  
M. V. Ivanov ◽  
A. S. Savvichev ◽  
A. A. Klyuvitkin ◽  
A. L. Chul’tsova ◽  
E. E. Zakharova ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Water Column ◽  
Caspian Sea ◽  
The Caspian Sea

scholarly journals THE DISTRIBUTION OF DISSOLVED FORMS COPPER IN THE WATER COLUMN OF THE CASPIAN SEA

2018 ◽  
Author(s):  
В.В. Ковалев ◽  
С.Г. Парада
Keyword(s):  
Surface Layer ◽  
Spatial Distribution ◽  
Water Column ◽  
Caspian Sea ◽  
Sea Water ◽  
Average Content ◽  
Vital Activity ◽  
The Caspian Sea ◽  
Organic Complexes ◽  
High Concentrations

По результатам химических анализов проб воды Северного, Среднего Каспия и, частично, Южного Каспия, отобранных по профилям из различных горизонтов водной толщи, определены содержания растворенных форм меди. Построены карты пространственного распределения этого элемента в поверхностном и наддонном водных горизонтах, а также по вертикальным разрезам водной толщи, выявлены закономерности их распространения в объеме морской воды. Установлены средние содержания растворенных форм меди в поверхностном (8,6 мкг/л) и в наддонном (9,6 мкг/л) горизонтах  Каспийского моря. Выделены участки с аномально высокими (более 20 мкг/л) и аномально низкими (менее 5 мкг/л) концентрациями растворенных форм меди в них. Особенности распределения растворенных форм меди по вертикали водной толщи определяются жизнедеятельностью планктонных организмов и их отмиранием. В поверхностном слое аномально высокие концентрации меди связаны с прижизненным накоплением металла планктоном. На глубинах свыше 100 м аномально высокие ее концентрации связаны с распадом отмерших организмов и выделением меди и других металлов в виде органических комплексов According to the results of chemical analyzes of water samples from the Northern, Middle Caspian and, partially, the Southern Caspian, taken from profiles from different horizons of the water column, the contents of dissolved forms of copper were determined. Maps of the spatial distribution of this element in the surface and supra-aquatic horizons, as well as along vertical sections of the water column, have been constructed, and patterns of their distribution in the volume of sea water have been revealed. The average content of dissolved forms of copper in the surface (8.6 μg/l) and in the above bottom (9.6 μg/l) horizons of the Caspian Sea has been established. Selected areas with abnormally high (more than 20 μg/l) and abnormally low (less than 5 μg/l) concentrations of dissolved forms of copper in them. The specific features of the distribution of dissolved forms of copper along the vertical of the water column are determined by the vital activity of planktonic organisms and their death. In the surface layer, abnormally high concentrations of copper are associated with the lifetime accumulation of metal by plankton. At depths above 100 m, its abnormally high concentrations are associated with the decay of dead organisms and the release of copper and other metals in the form of organic complexes

Environmental impacts of physical and dynamical characteristics of the southern coastal waters of the Caspian Sea

2021 ◽  
pp. 1-14
Author(s):  
Siamak JAMSHIDI ◽  
Mahdieh JAFARI
Keyword(s):  
Water Column ◽  
Caspian Sea ◽  
General Circulation ◽  
Middle Part ◽  
Marine Debris ◽  
The Caspian Sea ◽  
Seasonal Thermocline ◽  
Field Samples ◽  
Current Characteristics ◽  
Coastal Flow

ABSTRACT This research evaluated the variability of current characteristics and seawater properties in the middle part of the southern shelf of the Caspian Sea. The effect of the coastal flow on marine debris dispreading was assessed in the southern Caspian Sea for the first time. The findings showed the existence of thermal stratification containing seasonal thermocline with thickness of about 40 m in the water column. Maximum monthly along-shore current velocities around 1.3 m s−1 were observed in November and December. Monthly variations were clearly found in both flow velocity and local wind components. However, no significant levels of correlation between wind and current speeds were observed during the study in the region. In some cases, the mean monthly cross-shore component velocities were measured at about 29 cm s−1 in November. The findings indicated that there was no upwelling phenomenon associated to the regional wind in the study area. In situ current measurements indicated dominant east and north-northeast directions, presumably related to the effect of general circulation in the southern basin. Current profiles in the water column displayed similarity in directions at 10, 15 and 20 m depths over the continental shelf. The field samples and analysis revealed that the soft and smaller-scale seawater litters can be carried long distances by the current along the coast. Most coastal based and marine litters originated from the tourist activities (in the middle and western parts of the shores) and waste emanated from the river (Tonekabon-Nowshahr).

scholarly journals Hydrology-hydrochemical researches of the Caspian Sea in July-August 2019

Trudy VNIRO ◽  
2020 ◽  
Vol 180 ◽  
pp. 174-178
Author(s):  
N. I. Torgunova ◽  
N. V. Arzhanova ◽  
A. S. Hursanov ◽  
O. A. L’vova
Keyword(s):  
Hydrogen Sulfide ◽  
Organic Carbon ◽  
Caspian Sea ◽  
Vertical Structure ◽  
Nitrate Nitrogen ◽  
Distribution Patterns ◽  
Summer Season ◽  
Research Information ◽  
The Caspian Sea ◽  
Sulfide Layer

Comprehensive research information on hydrology-hydrochemical structure of the Middle Caspian Sea in July-August 2019 on board of R/V “Issledovatel’ Kaspiya” is presented in the article. Data on dissolved oxygen, hydrogen sulfide, basic nutrients (ammonium, nitrite and nitrate nitrogen; mineral phosphorus) and dissolved organic carbon were obtained in four quasi-latitudinal sections using the probing complex SBE19 plus Sea Bird, equipped with a series of sensors and twelve Niskin bathometers. It is shown, that the distribution patterns of determined elements and vertical structure correspond to average annual values of the summer season. Despite the sea level decline, the thickness of hydrogen sulfide layer of the Caspian Sea hasn’t decreased.

scholarly journals Spatio-temporal variability of organic matter contents in the waters of the Caspian Sea

2019 ◽  
Vol 46 (1) ◽  
pp. 70-81
Author(s):  
A. I. Agatova ◽  
N. I. Torgunova ◽  
E. A. Serebryanikova ◽  
L. K. Dukhova
Keyword(s):  
Organic Matter ◽  
Hydrogen Sulfide ◽  
Caspian Sea ◽  
Vertical Mixing ◽  
Qualitative Change ◽  
Border Region ◽  
The Caspian Sea ◽  
Sea Levels ◽  
The North ◽  
Spatio Temporal

We analyzed spatio-temporal changes in concentrations and elemental compositions of dissolved organic matter in the waters of the Caspian Sea over the period 2010–2015. These studies showed that over the past 5 years of lowering of sea levels, mean concentrations of Corg and Norg remained virtually unchanged, whereas concentrations of Porg decreased more than three-fold, suggesting a qualitative change in organic matter. Based on data averages, concentrations of Corg, Norg, and Porg in Southern waters were slightly higher than in the North and Middle-Caspian waters during the monitoring period. In deep areas at the border region of hydrogen sulfide occurrence, concentrations of Corg, Norg, and Porg increase. Hence, the presence of hydrogen sulfide in the deep waters of the Derbent and South Caspian basins, and the corresponding increase in organic matter contents, indicates no radical improvement of vertical mixing of the sea in these areas during the eight years of our regression model. Moreover, according to the carbohydrate distribution, organic substances of petroleum hydrocarbons contribute considerably to a common pool.

Biogeochemical processes in the water column of the Caspian Sea in November 2008

2010 ◽  
Vol 434 (2) ◽  
pp. 1381-1385 ◽  
Author(s):  
A. Yu. Lein ◽  
I. I. Rusanov ◽  
A. A. Klyuvitkin ◽  
M. D. Kravchishina ◽  
E. E. Zakharova ◽  
...  
Keyword(s):  
Water Column ◽  
Caspian Sea ◽  
Biogeochemical Processes ◽  
The Caspian Sea

Microbiological and biogeochemical properties of the Caspian Sea sediments and water column

Microbiology ◽  
2014 ◽  
Vol 83 (5) ◽  
pp. 648-660 ◽  
Author(s):  
A. Yu. Lein ◽  
A. S. Savvichev ◽  
M. D. Kravchishina ◽  
N. V. Kozina ◽  
V. I. Peresypkin ◽  
...  
Keyword(s):  
Water Column ◽  
Caspian Sea ◽  
The Caspian Sea

scholarly journals Features of the distribution of the suspended form of iron in the water column of the Caspian Sea

2021 ◽  
Author(s):  
В.В. Ковалев ◽  
К.Ю. Гамбург
Keyword(s):  
Surface Layer ◽  
Water Column ◽  
Caspian Sea ◽  
Chemical Elements ◽  
Suspended Particles ◽  
Solid Particles ◽  
Natural State ◽  
Caspian Basin ◽  
The Caspian Sea ◽  
Suspended Form

Статья посвящена изучению распределения железа в водной взвеси Среднего Каспия. Актуальность работыопределяется необходимостью оценки естественного состоя­ния морской среды и фиксации ее базового состояния (в том числе различных форм химических элементов) для дальнейшего использования с целью мониторинга экологической ситуации на шельфе Каспийского моря в условиях интенсификации геологоразве­дочных работ и разработки месторождений нефти. Цель работы. Установить характерные особенности поведения взвешенного железа в водах Среднего Каспия. Материалы и методы работы. Изучался материал, отобранный в 1989-1990 годах в ходе выполнения рейсов исследовательских судов. Принадлежащих Каспийскому НИИ рыбного хозяйства, до начала освоения нефтегазовых месторождений. Он представлен отфильтрованными частицами взвеси из 178 проб воды, взятых из различных слоев водной толщи на 63 станциях. Определение содержаний железа проводилось на спектрографе PGS-2 способом испарения. Результаты работы. Минимальные концентрации взвешенной формы железа в поверхностном слое водной толщи установлены на участке внутреннего шельфа и подводного склона котловины Среднего Каспия, что связано с выносом твердых частиц дрейфовыми течениями. Концентрации взвешенной формы железа в поверхностном слое возрастают к середине моря, что обусловлено стягиванием взвешенных частиц центростремительными силами циклонального течения. Придонный слой отличается повышенными концентрациями взвешенной формы железа. Возле дельт рек они связаны с оседанием выносимых с суши твердых частиц. Аномально высокие содержания взвешенной формы железа в придонном горизонте центральной части Среднекаспийской котловины, фиксируемые на отдельных станциях, обусловлены поступлением железа с эманациями донных грязевых вулканов и его коагуляцией в условиях щелочной среды. В целом, с увеличением глубины наблюдается последовательный рост концентраций взвешенной формы железа. Это связано с изменением солености и усилением вертикальной стратификации (уменьшением солености поверхностного горизонта и увеличением солености глубоких слоев). Это приводит к коагу­ляции и флокуляции органических и металлор­ганических коллоидов и переводу растворенного железа во взвесь The article is devoted to the study of the distribution of iron in the water suspension of the Middle Caspian Sea. The relevance of the work is determined by the need to assess the natural state of the marine environment and fix its basic state (including various forms of chemical elements) for further use in order to monitor the environmental situation on the shelf of the Caspian Sea in the conditions of intensification of exploration and development of oil fields. Aim. To establish the characteristic features of the behavior of suspended iron in the waters of the Middle Caspian. Materials and methods. The material selected in 1989-1990 during the voyages of research vessels was studied. owned by the Caspian Research Institute of Fisheries, before the development of oil and gas fields. It is represented by filtered suspended particles from 178 water samples taken from various layers of the water column at 63 stations. Determination of iron content was carried out on the PGS-2 spectrograph by evaporation. Results. The minimum concentrations of the suspended form of iron inthe surface layer of the water column were established on the section of the inner shelf and the underwater slope of the Middle Caspian basin, which is associated with the removal of solid particles by drift currents. The concentrations of the suspended form of iron in the surface layer increase towards the middle of the sea, which is caused by the contraction of suspended particles by the centripetal forces of the cyclonic current. The bottom layer is characterized by increased concentrations of the suspended form of iron. Near river deltas, they are associated with the subsidence of solid particles carried out from the land. Abnormally high concentrations of suspended iron in the bottom horizon of the central part of the Middle Caspian basin, recorded at individual stations, are due to the influx of iron with emanations of bottom mud volcanoes and its coagulation in an alkaline environment. In general, with increasing depth, there is a consistent increase in the concentrations of the suspended form of iron. This is due to a change in salinity and an increase in vertical stratification (a decrease in the salinity of the surface horizon and an increase in the salinity of the deep layers). This leads to coagulation and flocculation of organic and organometallic colloids and the transfer of dissolved iron into suspension.

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