scholarly journals Assessment of bottom sediments accumulation intensity in the Kuyalnyk estuary

2017 ◽  
Keyword(s):  
Bottom Sediments ◽  
Accumulation Rate ◽  
Average Rate ◽  
Natural Radionuclides ◽  
Middle Part ◽  
The Black Sea ◽  
Spectrometric Analysis ◽  
Layer By Layer ◽  
Cesium 137 ◽  
Potassium 40

Purpose. Assessment of bottom sediments accumulation rate for two areas of the Kuyalnyk Estuary using radionuclide method. Methods. The study has been done in two areas of the Kuyalnyk Estuary: the middle part near Kovalivka village and the lower part to the north from the sanatorium, using the standard methods of sediment columns sampling and gamma-spectrometric analysis of radionuclides concentration. Results. Based on the results of the studies of 2016, layer-by-layer concentrations of Cesium-137, Potassium-40, Radium-226 and Torium-232 were determined. Analysis of vertical profiles of Cesium-137 concentrations enabled us to assess, for the first time, the intensity of sediments accumulation in two areas of the estuary for the periods 1962-1986-2016, which later were used for indicative dating of anomalies in the distribution of natural radionuclides Potassium-40, Radium-226 and Torium-232 concentrations. Conclusions. It has been shown that in the lower and middle parts of the Kuyalnyk Estuary the average rate of sediments accumulation in 1986 – 2016 made 0.8±0.1 mm/year and 1.8±0.2 mm/year respectively. In 1962-1986 sediments accumulation rate was practically the same in both parts of the estuary and made 1.9±0. mm/year. The average values for the period 1962-2016 made 1.6±0.1 mm/year and 1.8±0.2 mm/year for the lower and middle parts of the estuary respectively. It has been proposed to perform additional mineralogical studies for more precise dating of the sediment layers accumulated before 1962 and to use radionuclide method for determination of sediment accumulation rate in other water bodies of the Black Sea region.

scholarly journals Distribution of 137Cs and 40K in the Bottom Sediments of the Balaklava Bay (the Black Sea)

2021 ◽  
Vol 37 (2) ◽  
Author(s):  
D. A. Kremenchutskii ◽  
K. I. Gurov ◽  
◽  
Keyword(s):  
Spatial Variability ◽  
Bottom Sediments ◽  
Sedimentation Rate ◽  
Average Rate ◽  
Measurement Data ◽  
The Black Sea ◽  
Spectrometric Analysis ◽  
Quantitative Estimates ◽  
The Relationship ◽  
Direct And Indirect Methods

Purpose. The aim of the work is to study spatial variability of the 137Cs and 40K concentrations in the bottom sediments of the Balaklava Bay, and to estimate the sedimentation rate and relative content of the biogenic fraction. Methods and Results. The results of the 137Cs and 40K concentration measurements in 5 columns of the bottom sediments sampled in various parts of the Balaklava Bay are represented. Activity of 137Cs and 40K in the samples was determined by the gamma spectrometric analysis. Based on the measurement data, spatial variability of the 137Cs and 40K concentration fields in the bottom sediments was studied, and the sedimentation rate was quantitatively estimated. Application of the balance equation provided quantitative estimates of the relative biogenic fraction content; its spatial variability was described. Quantitative estimates of the relationship between the biogenic fraction estimates resulted from use of the direct and indirect methods are represented. Conclusions. According to the obtained results, the 137Cs and 40K concentrations in the upper 5 cm layer of bottom sediments varied in space from 11 to 62 and from 155 to 562 Bq/kg, respectively. The maximum radionuclide concentrations were characteristic of the northern part of the bay, the minimum ones – of its southern part. The sedimentation average rate was 0.51 ± 0.06 cm/year. Relative biogenic fraction content in the sediments varied in space from 30 to 89% and averaged 46 ± 25%. The maximum values were observed in the southern part of the bay, the minimum ones – in the northern part.

scholarly journals Distribution of 137Cs and 40K in the Bottom Sediments of the Balaklava Bay (the Black Sea)

2021 ◽  
Vol 28 (2) ◽  
Author(s):  
D. A. Kremenchutskii ◽  
K. I. Gurov ◽  
◽  
Keyword(s):  
Spatial Variability ◽  
Bottom Sediments ◽  
Sedimentation Rate ◽  
Average Rate ◽  
Measurement Data ◽  
The Black Sea ◽  
Spectrometric Analysis ◽  
Quantitative Estimates ◽  
The Relationship ◽  
Direct And Indirect Methods

Purpose. The aim of the work is to study spatial variability of the 137Cs and 40K concentrations in the bottom sediments of the Balaklava Bay, and to estimate the sedimentation rate and relative content of the biogenic fraction. Methods and Results. The results of the 137Cs and 40K concentration measurements in 5 columns of the bottom sediments sampled in various parts of the Balaklava Bay are represented. Activity of 137Cs and 40K in the samples was determined by the gamma spectrometric analysis. Based on the measurement data, spatial variability of the 137Cs and 40K concentration fields in the bottom sediments was studied, and the sedimentation rate was quantitatively estimated. Application of the balance equation provided quantitative estimates of the relative biogenic fraction content; its spatial variability was described. Quantitative estimates of the relationship between the biogenic fraction estimates resulted from use of the direct and indirect methods are represented. Conclusions. According to the obtained results, the 137Cs and 40K concentrations in the upper 5 cm layer of bottom sediments varied in space from 11 to 62 and from 155 to 562 Bq/kg, respectively. The maximum radionuclide concentrations were characteristic of the northern part of the bay, the minimum ones – of its southern part. The sedimentation average rate was 0.51 ± 0.06 cm/year. Relative biogenic fraction content in the sediments varied in space from 30 to 89% and averaged 46 ± 25%. The maximum values were observed in the southern part of the bay, the minimum ones – in the northern part.

scholarly journals Assessment of radionuclide contamination of plant resources of the Voronezh region by example of leaves of winter linden tree

2020 ◽  
pp. 87-93
Author(s):  
N. A. Dyakova
Keyword(s):  
Raw Materials ◽  
Natural Radionuclides ◽  
Plant Resources ◽  
Accumulation Coefficient ◽  
Average Value ◽  
The Core ◽  
Strontium 90 ◽  
Cesium 137 ◽  
Potassium 40 ◽  
Thorium 232

As part of the study, the activity of artificial and natural radionuclides (strontium-90, cesium-137, potassium-40, thorium-232, radium-226) was determined in 36 samples of medicinal plant raw materials of the core and upper soil layers on which the plants were grown. All samples meet the existing requirements of regulatory documentation on radionuclide activity. The average value of the strontium-90 accumulation coefficient was 0.39, in different samples of the region it varied from 0.31 to 0.60. Cesium-137 accumulation coefficients ranged from 0.29 to 0.65 at an average of 0.39. For thorium-232, the average accumulation coefficient in the core lip flowers is 0.15 and took values in the samples studied from 0.09 to 0.231. For potassium-40, the average accumulation ratio in the feed was 0.98 and varied from 0.71 to 1.29, and for radium-226 - 0.47, with a variation from 0.39 to 0.59.

Significance of Mineralogical and Lithologic-Petrographical Rank in the Ranking of Geological Information

2020 ◽  
Vol 42 (4) ◽  
pp. 33-49
Author(s):  
O.V. CHEPIZHKO ◽  
V.V. YANKO ◽  
V.M. KADURIN ◽  
I.M. NAUMKO ◽  
S.M. SHATALIN
Keyword(s):  
Fluid Flow ◽  
Black Sea ◽  
Bottom Sediments ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
Geochemical Characteristics ◽  
The Black Sea ◽  
Flow Parameters ◽  
Geochemical Parameters ◽  
Geological Information

For the first time the importance of mineralogical and lithological-petrographical ranks in the line of geological information ranks is substantiated for implementation of long-term forecasts, standard and non-standard approaches to research of physical and geochemical parameters as a basis of creation of complex system of forecast criteria and prospecting indicators of hydrocarbons within the sedimentary cover of Black sea based on the theory of global fluid-flows derivation. These criteria have different sensitivity to the object (hydrocarbon deposits) and are therefore ranked. The ranking determined the following parameters: 1) seismic data within the object, obtained by the method of deep seismic sounding, RWM SDP; 2) parameters of tectono-geodynamic structures; 3) the main characteristics of sedimentary cover and bedrock; 4) geochemical characteristics; 5) parameters of mineral complexes and fluid inclusions in mineral neoformations; 6) the value of the distribution of meiobenthos. Based on modern views of oil and gas geology, structural-tectonic and lithological-facies criteria are among the main ones. The study of the mineralogical component of sediments is made with using mineralogical, thermobarogeochemical and X-ray spectral methods. Fixation of anomalies of fluid flow at the bottom of the Black Sea as to the distribution of abiotic parameters in order to assess the prospects of oil and gas is determined by structural and tectonic features and high permeability of fluid flow; parameters of mineral complexes (minerals, facies) and genetic connections; heterogeneity of geochemical characteristics of bottom sediments; the presence of hydrocarbon inclusions in authigenic minerals of bottom sediments.

scholarly journals The Study of Uranium Accumulation in Marine Bottom Sediments: Effect of Redox Conditions at the Time of Sedimentation

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 332
Author(s):  
Nadezhda Khaustova ◽  
Yulia Tikhomirova ◽  
Svetlana Korost ◽  
Elena Poludetkina ◽  
Andrey Voropaev ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
White Sea ◽  
Uranium Content ◽  
Black Shales ◽  
Redox Conditions ◽  
Source Rocks ◽  
Shelf Zone ◽  
The Black Sea ◽  
The White Sea ◽  
Run Off

To evaluate the effect of redox conditions at the sedimentation stage on uranium content and U/TOC ratio in marine source rocks, we analyzed the accumulation of uranium in modern marine bottom sediments formed in different redox conditions. The behavior of uranium from bottom sediments formed in oxidizing and sub-oxidizing settings has been studied on the sediments of the Upper Pleistocene–Holocene age accumulated in the coastal area of the White Sea (Kandalaksha Gulf). We studied the content of uranium, Eh, pH, TOC, C, H, N, and S element and isotope compositions and other parameters in two sampled columns of bottom sediments at a depth of 0–2.5 m. The composition of sediments was typical for the shelf zone where marine genesis mixes with the continental run-off. The upper layer of sediments (0–50 cm) were characterized by oxidizing conditions (Eh ~ 400 mV); with the increase in depth, redox conditions changed from oxidizing to reducing (0 ÷ 200 mV). The uranium concentration in the upper layer was 1–1.5 ppm, U/TOC ratio varied in the range of 0.8–1.1 ppmU/%TOC. The uranium content and U/TOC ratio increased up to the values of 2.6 ppm and 1.4 ppmU/%TOC at a depth of 0.5−2.5 m, respectively, but the general content of uranium in the studied environment was close to the values characterizing continental run-off. The results obtained for the White Sea sediments were compared with the sediment of the Black Sea, formed in the anoxic conditions of hydrogen sulfide contamination. In these conditions, the uranium content varied from 10 to 20 ppm. The obtained data were interpreted using thermodynamic modeling of the uranium forms in the seawater at different pH and Eh. This study demonstrated that the change of redox conditions from oxidizing to reducing leads to increased uranium content due to a decrease in uranium’s solubility in water. These results show that oxidation–reduction potential could be one of the most important factors controlling uranium content in black shales formed in the marine environment.

Anthropogenic Impact on the Lithodynamics of the Coastal Zone of the Southern and Western Black Sea Coast (Review)

2021 ◽  
Author(s):  
T. V. Efremova ◽  
Yu. N. Goryachkin ◽  
◽  
Keyword(s):  
Coastal Zone ◽  
Black Sea ◽  
Bottom Sediments ◽  
Anthropogenic Impact ◽  
River Flow ◽  
The Black Sea ◽  
Negative Consequences ◽  
Coastal Zones ◽  
Natural Dynamics ◽  
The Impact

Anthropogenic impact on lithodynamics of the coastal zone changes the natural dynamics of bottom sediments, which leads to increased abrasion and swelling of beaches, activation of landslide processes creating a threat of destruction of the coastal infrastructure. The article aims at providing an overview of the scientific literature on the anthropogenic impact on lithodynamics of the coastal zone of the southern and western coasts of the Black Sea (shores of Romania, Bulgaria and Turkey). The work shows that with all the differences in the natural conditions of the coastal zones of these countries the types of anthropogenic effects they undergo are almost the same. These include: hydrotechnical construction without regard to the impact on the neighbouring coast sections; reduction of solid river flow due to river regulation by reservoirs; construction of capital facilities directly on the beaches; illegal extraction of sand from beaches and river beds; dredging with sale of the extracted material to construction companies; covering of cliffs by various structures; destruction of coastal dunes, etc. The main negative consequences of these actions are reflected in disruption of natural dynamics and shortages of bottom sediments, changes in the coastline, reduced aesthetic attractiveness and accessibility of shores, destruction of coastal ecosystems. The article also provides information on the legislation of these countries regarding environmental management in the coastal zone

scholarly journals Features of accumulation of the technogenic radionuclides in meat of some hunting animals in the Trans-Urals

2019 ◽  
pp. 47-52
Author(s):  
Alexander Mikhailovich Okunev
Keyword(s):  
Specific Activity ◽  
Natural Radionuclides ◽  
Farm Animals ◽  
Beta Activity ◽  
Radioactive Cesium ◽  
Anthropogenic Pressure ◽  
Wild Animals ◽  
Strontium 90 ◽  
Cesium 137 ◽  
Lead 210

The degree of contamination of the organism of wild animals with radionuclides is of particular importance in the framework of environmental monitoring and assessment of its safety, both for humans and for animals. However, the majority of domestic scientific works on this subject concerns farm animals, and the information relating to hunting animals is much less. This fact determined the relevance of our work, the purpose of which was to study the features of the accumulation of global technogenic and natural radionuclides in the meat of some wild animals in the TRANS-Urals. Experimental data on the content of technogenic radionuclides in the meat of hunting animals were obtained in the autumn-winter periods of 2014 – 2018. Analysis of the average data showed, that the content in the meat of wild animals cesium-137, depending on the animal species, ranged from 4.1 to 49.2; lead-210 – 0,7 – 4,3; and strontium-90 – 0,1 – 1,7 Bq/kg. The total beta- activity of radionuclides in the meat of wild animals varied, depending on the species, from 71.2 to 104.3 Bq/kg. At the same time, all the studied samples of meat corresponded to the norms established by SanPiN-2010 for this type of food product. Some increased accumulation of radioactive cesium (49.2 Bq/kg) and other anthropogenic radionuclides was observed in wild reindeer meat, and in the southern regions of the TRANS-Urals – in bear and wild boar meat (21.1 and 17.4 Bq/kg, respectively). In the muscle tissue of the roe deer the content of this radionuclide was slightly higher than that of the elk (14.7 and 12.2 Bq/kg, respectively). The lowest concentration of cesium-137 (4.1 Bq/kg) and other nuclides was found in beaver meat. The content of strontium-90 in the meat of all tested animals was at a minimum level, and the specific activity of lead-210 was higher than strontium-90 by 2 - 10 times, depending on the species, which indicates the accumulation of this radionuclide in forest ecosystems due to anthropogenic pressure and expansion of the technogenic zone of cities.  The results of studies have shown that differences in the accumulation of technogenic radionuclides in the meat of the hunting animals are largely related to the nature of feeding and composition of the diet of wild species, and are subject to significant fluctuations in accordance with the change in the volume and qualities of food resources in forest biotopes over the year.      

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