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1

Experimental Research for Metocean Data and Risks in the Vicinity of Platforms in the Black Sea

Voicu Ionut, Panaitescu Mariana, Panaitescu Fanel-Viorel, Vasilica Florentina Aurelia

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2025

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Vol. 19 No. 1

235--240

EN

The knowledge of the metocean data is important for the design and construction of different equipment in offshore area. The paper presents an analysis of environmental factors in different conditions in the location of study, GALATA platform, Bulgaria. The results of the analysis (wind statistics, wind distribution rose, wind speed extreme, monthly mean vertical profile of wind speed) cover the period 2008-2023. To analyse correct design of floating wind turbines must establish wind speed extreme. The data sets obtained were validated using the CFS3D wind database. To study the risks in vicinity of platforms we used tools of NEAT+ software which provides the opportunity to make informed decisions and implement appropriate preventive and corrective measures to protect the environment. The results of the experimental research indicate a favourable general state of the environment in the Black Sea vicinity of platforms area.

2

Crustacean species off the coast of Kıyıköy (Black Sea, Türkiye) with a new record

Özgenç Özge, Açık, Şermin

Oceanological and Hydrobiological Studies

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2024

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Vol. 53, No. 3

249--260

EN

Examination of hard- and soft-bottom samples collected off the coast of Kıyıköy (Black Sea, Türkiye) using grabs, quadrats and trawls revealed a total of 39 crustaceans belonging to eight orders. Among the species, Medorippe lanata was recorded in the Black Sea for the first time. Amphipoda dominated on hard and soft substrates in terms of the number of species and individuals. A total of 898 individuals belonging to 27 species were identified on the hard bottom, of which Ampithoe ramondi was the most dominant species (47.4%). On the other hand, a total of 123 individuals belonging to 16 species were recorded on the soft bottom, with Diogenes pugilator (21.1%) being the most dominant species (21.1%). A total of 441 individuals belonging to nine species were found following bottom and beam trawl hauls, with Liocarcinus navigator and L. depurator being the most frequent species. Community parameters were estimated in both hard- and soft-bottom samples.

3

Environmental Variables Significance for Ecological Status Assessment in the Bulgarian Eastern Continental Shallow Lakes

Doychev Dimitar, Gartsiyanova Kristina, Taneva Lidiya

Journal of Ecological Engineering

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2024

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Vol. 25, nr 10

16--30

EN

Eastern Continental shallow lakes are specific with their higher nutrient concentration compared to other lentic water bodies with similar specifications. Nonetheless, their phytoplankton and macrophyte assessment systems used more often than others within state monitoring programs, are weakly influenced by nutrient concentrations, unlike all other lake types in Europe. In this study, we used all available data for Eastern Continental shallow lakes on the Black Sea coast of Bulgaria from the state monitoring for 14 years (2008–2021). The goal was to find how environmental variables influence the ecological status assessment by phytoplankton and macrophyte-related indices. Likewise, it was important to understand the studied parameter’s interrelations within Dourankoulak Lake and the lake complex Shabla-Ezerets. The most important environmental parameters were determined with principal component analysis since it helps find the hidden relationships. Afterwards, those variables were used for univariate linear regression testing because of its simplicity and reliability. The aim was to find the best-suited parameters for the ecological status explanation by different biological indices, which can be used for further predictions of the ecosystem condition. In addition, nitrogen–phosphorus dependency, where possible was investigated, confirming conclusions from mesocosms studies from water bodies with similar characteristics. The algae group index or the so-called “Catalán Index”, in its original form of representing results and considering its ecological quality ratio values, was influenced by conductivity concentrations the most in Ezeretsko Lake and weaker at Dourankoulak Lake. Nutrient relationship with biological quality elements was not found, confirming results on a European level. In Shablensko Lake a dose-dependent relation between nitrates and phosphates was found, which shows that augmenting the quantity of nitrogen is related to the increasing concentration of phosphates.

4

The Impact of the Russian Armed Aggression on the Condition of the Water Area of the Dnipro-Buh Estuary System

Pichura Vitalii, Potravka Larysa, Dudiak Nataliia, Hyrlya Lyudmila

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 11

58--82

EN

The Russian armed aggression is claiming lives of thousands of people, exerting disastrous pressure on the environment of Ukraine, destroying natural landscapes, flora and fauna species, polluting water bodies, damaging a fertile soil layer, poisoning the environment with oil products and heavy metals. Combat zones, frontline areas and occupied territories are suffering most. The purpose of the research was to establish spatio-temporal patterns of the formation of surface water quality in 2018–2023 and determine the impact of the Russian armed aggression on the functioning of the water area of the Dnipro-Buh estuary system. The research was carried out using hydrological, biological and physical-chemical indicators. The negative consequences of the hostilities causing the destruction of the Kakhovka hydroelectric power station dam in 2023 and the drainage of the water reservoir, discharge of pollutants with a concentration of 1.1–51.8 MPC and pollution in the water area of 6800 km2 of the estuary system and the Black Sea were identified. The dam destruction has a number of negative environmental and socioeconomic consequences. Seasonal indicators of the hydrological regime of the Dnipro-Buh estuary system testified to deterioration of the system condition by 1.42–1.82 time. In particular, there was stagnation of water masses, an increase in the saturation of water sources with biogenic elements by 2.1 times, a rise in the density of algae distribution, an increase in chlorophyll concentration by 2.9 times. Deterioration of the condition of surface waters to the Polytrophic state and deterioration of physical-chemical properties of water by 4.0 times was also identified. The research findings prove that the damage to the environment can be regarded as ecocide that is an important informational base for developing the measures and implementing technologies of post-war restoration of the ecological condition of water bodies and ensuring their zonal sustainability.

5

Environmental risk assessment in the background of armed conflict in the Black Sea Area. A case study for a container terminal in the port of Constanța

Stefanov N. O., Rauca L.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 3

545--551

EN

The year 2022 was marked by economic risks with potentially very sensitive impacts for countries in the Black Sea region. Given the limited capacity of Ukrainian ports, as well as the sanctions imposed on Russia, due to ongoing conflict, it was necessary to identify new destinations capable of taking over the flow of goods that normally went to the countries involved in this conflict. In addition to the risks specific to maritime transport, the risk of armed conflict comes with new challenges that can also materialize in the form of environmental impact. To analyze this potential impact, the study is being focused mainly on the analysis of the pollution risk generated by the emissions caused by the vessels calling the container terminal CSCT, located in Constanța harbor, and the emissions generated by the vehicles moving in the terminal. As estimated from the start all levels of pollution have increased, with the level of CO2 increasing from 11072.7 tons in 2021 to 11915.7 tons in 2022. The NOx emissions have a similar trend, as well as the other emission level measured and calculated.

6

Measuring economic resilience for the CEE and Black Sea countries in the framework of comprehensive defense

Constantinescu Maria

Security and Defence Quarterly

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2023

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Vol. 44, No. 4

55--83

EN

The main research objective of this paper is to identify key factors influencing economic resilience from the perspective of comprehensive defence. This involves developing a composite economic resilience index (Ericda) that outlines the relative economic resilience of countries in Central and Eastern Europe and the Black Sea regions, within the comprehensive defence framework. The paper employs qualitative research methods, focusing on an analysis of specialist literature pertaining to economic resilience. Quantitative methods are also used for developing the Economic Resilience Index from the Comprehensive Approach to Defence (Ericda) perspective. This includes using data on selected resilience indicators in Central and the Eastern European and Black Sea region countries to generate rankings. The results of the study reveal strong positive correlations between the economic resilience index and various factors, such as logistics and infrastructure, economic complexity, foreign trade vulnerabilities and dependence, economic stability and development, governance effectiveness, military, and human capital. Additionally, a negative correlation was observed with the resilience index. The research findings suggest that to ensure effective comprehensive defence, isolated measures targeting individual pillars are inadequate. Economic resilience requires a collaborative approach, extending beyond the purview of the finance ministry and involving a broader range of stakeholders.

7

Drony-kamikadze kontra okręty - wybrane aspekty wojny na Morzu Czarnym 2022-2023

Rochowicz Robert

Problemy Techniki Uzbrojenia

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2023

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R. 52, z. 167

271--282

PL

Wojna ukraińsko-rosyjska przynosi od początku jej trwania wiele zaskakujących rozstrzygnięć militarnych. Bez wątpienia jednym z nich jest sytuacja rosyjskiej marynarki wojennej na Morzu Czarnym. Ukraina nie posiada już w zasadzie żadnego okrętu bojowego, a jednak potrafi innymi siłami i środkami wykonywać skuteczne uderzenia, co i rusz uszczuplając stan posiadania strony przeciwnej eliminując definitywnie lub poważnie uszkadzając kolejne jednostki pływające. W artykule przedstawiono aktualny stan wiedzy, dotyczącej używanych przez Ukrainę morskich bezzałogowych pojazdów bezzałogowych, opartej, co oczywiste, przede wszystkim na podstawie potwierdzonych doniesień agencyjnych z toczącej się wojny ukraińsko-rosyjskiej oraz wszelkich udostępnianych przez Ukrainę materiałów, pozwalających poznać szczegóły taktyczno-techniczne tego rodzaju uzbrojenia.

8

On the possibility of the utilization of hydrogen sulfide from the Black Sea

Simova Iskra, Velichkova Rositsa, Uzunova Milka, Angelova Radostina, Stankov Peter, Atanasov Koycho

Polityka Energetyczna

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2023

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T. 26, z. 2

183--194

EN

Looking for alternative sources of energy to generate electricity has been a hot topic for society for a very long time. The need to replace current energy resources such as fuel, oil, and gas is increasing, and the replacement comes from energy obtained from the wind, sun, and sea waves. In many cases, valuable raw materials can be obtained in addition to energy production, while having a significant environmental effect simultaneously. The shortage of energy and raw material resources in many countries stimulates the growth of interest in all potential sources of energy – solar, wind, wave, tidal – has lead to accelerating the demand for oil and gas, shale gas, as well as the expansion of the areas for the cultivation of technical crops for biofuels. Classical energy resources like oil, gas and coal are serious polluters of the natural environment. Especially harmful is the release of carbon dioxide and sulfur oxides during the exploitation of these resources. A significant energy raw material potential of non-traditional resources lies in the waters and bottom of the Black Sea, which is a natural geobiotechnological reactor, capable of producing a variety of energy raw resources. This paper discusses the use of hydrogen sulfide available in the Black Sea waters to produce energy and useful industrial products and proposes the respective. The technology also has an ecological effect in terms of the purification of the hydrogen sulfide pool. The paper also discusses some technologies for the separation of hydrogen sulfide to hydrogen and sulfur. An estimation of the heat value of hydrogen sulfide in the water of the Black Sea is also presented.

PL

Poszukiwanie alternatywnych źródeł energii do produkcji energii elektrycznej od dawna jest gorącym tematem w społeczeństwie. Konieczność zastąpienia obecnych źródeł energii, takich jak paliwo, ropa naftowa i gaz, jest coraz większa, a pochodzi ono z energii pozyskiwanej z wiatru, słońca i fal morskich. W wielu przypadkach, oprócz produkcji energii, można pozyskać cenne surowce, mając jednocześnie znaczący wpływ na środowisko. Niedobór surowców energetycznych i surowcowych w wielu krajach stymuluje wzrost zainteresowania wszystkimi potencjalnymi źródłami energii – słońcem, wiatrem, falami, pływami – doprowadził do przyspieszenia popytu na ropę i gaz, gaz łupkowy, a także ekspansji powierzchni pod uprawę roślin technicznych na biopaliwa. Klasyczne źródła energii, takie jak ropa naftowa, gaz i węgiel, poważnie zanieczyszczają środowisko naturalne. Szczególnie szkodliwe jest wydzielanie się dwutlenku węgla i tlenków siarki podczas eksploatacji tych zasobów. Znaczący potencjał surowcowy energii nietradycyjnych zasobów tkwi w wodach i dnie Morza Czarnego, które jest naturalnym reaktorem geobiotechnologicznym, zdolnym do produkcji różnorodnych surowców energetycznych. W artykule omówiono wykorzystanie siarkowodoru dostępnego w wodach Morza Czarnego do produkcji energii i użytecznych produktów przemysłowych oraz zaproponowano odpowiednie rozwiązania. Technologia ma również efekt ekologiczny w zakresie oczyszczania basenu siarkowodoru. W artykule omówiono również niektóre technologie rozdziału siarkowodoru na wodór i siarkę. Przedstawiono również oszacowanie wartości opałowej siarkowodoru w wodach Morza Czarnego.

9

The high-impact sea-effect snowstorm of February 2020 over the southern Black Sea

Demirtaş Meral

Acta Geophysica

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2023

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Vol. 71, no. 3

1361--1371

EN

The early February 2020 wintry weather set in across the southern Black Sea and northern coastal region of Turkey. During the high-impact snowstorm event, northerly winds carried cold arctic air across the relatively warmer Black Sea, which caused intense sea-effect snow showers. The omega-block pattern was present on successive days. Atmospheric blocking analysis was conducted with an objective two-dimensional index. Blocking analysis indicated that it was related to quasi-stationary the north-eastern Atlantic ridge, which was the most favourable position for leading to cold spells over the Black Sea, because it enabled a prominent downstream trough there. Key factors conducive to sea-effect snowfall over the southern Black Sea were noted highlight for this weather phenomenon: (i) an upper-tropospheric trough—which carried warm and moist air masses from the Black Sea towards the lands; (ii) a prolonged ridge in the upper troposphere—which was associated with a blocking anticyclone at the surface; (iii) directional wind shear was less than 60° at the boundary layer; (iv) low-level winds were approximately 10–15 ms−1 and suitable wind direction; (v) temperature differences between the sea surface and the 850-hPa level were higher than critical limit of 13 °C; (vi) the ratio between the average low-level wind and the fetch was 0.033, which was good enough for cloud formation. Main findings indicated that the dynamical factors and meso-scale ingredients triggering and maintaining this sea-effect snowstorm were satisfactory, and they were essential to pinpoint the underlying factors of high-impact sea-effect snowfall.

10

Feeding intensity and daily mussel consumption of Rapa whelk (Rapana venosa) in the north-western Black Sea

Stadnichenko Svitlana, Kurakin Aleksandr

Oceanological and Hydrobiological Studies

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2022

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Vol. 51, No. 4

334--354

EN

Based on an experiment carried out in the north-western Black Sea (Snake Island), the feeding behavior of the Rapa whelk (Rapana venosa Valenciennes, 1846) was analyzed in relation to its size (N = 58; shell height: 30–90 mm). Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) were placed in experimental cages with R. venosa to be used as food. It was found that the size of the prey was determined by the size of the predator. The mussels with a shell length of 20−40 mm were most affected by R. venosa. It was determined that the predator’s contribution to the deposition of mussel shells in the bottom sediments is also associated with its size. Feeding intensity varies from 41 mg to 99 mg of the total mass of mussels per 1 g of the total mass of R. venosa per day, depending on the size of the predator. The daily consumption of mussel soft tissue varied from 0.189 g ind.−1 per day−1 in small R. venosa specimens to 0.917 g ind.−1 per day−1 in large predators. Regression equations were obtained between the length and mass of the mussels consumed (total mass, soft tissue mass and shell mass) and the shell height of the predator.

11

Habitat suitability models of five keynote Bulgarian Black Sea fish species relative to specific abiotic and biotic factors

Zlateva Ivelina, Raykov Violin, Slabakova Violeta, Stefanova Elitsa S., Stefanova Kremena B.

Oceanologia

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2022

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No. 64 (4)

665--674

EN

Over the past few years, predicting species spatial distributions has been recognized as a powerful tool for studying biological invasions in conservation biology and planning, ecology, and evolutionary biology. Species spatial distribution models (SDMs) are used extensively for assessing the effects of changes in habitat suitability, the impacts of climate change, and the realignment of the existing conservation priorities. SDMs relate known patterns of species occurrences to a specific set of environmental conditions. Accordingly, we have used MaxEnt SDM tool in order to provide habitat suitability models of 5 keynote fish species: European sprat (Sprattus sprattus L.), red mullet (Mullus barbatus, L.), horse mackerel (Trachurus mediterraneus, L.), bluefish (Pomatomus saltatrix, L.) and whiting (Merlangius merlangus, L.), inhabiting the Bulgarian region of the Black Sea. Presence-only (PO) data collected by pelagic surveys performed between 2017 and 2019 was further utilized to link known species occurrence localities with selected abiotic factors, such as surface sea temperature and salinity, dissolved oxygen, and speed of currents. Biotic interactions were also considered for fitting the patterns of habitat suitability models. The SDMs, obtained from the present research study, prove to have satisfactory predictive accuracy to be further implemented for conservation measures and planning, stock management policy-making, or ecological forecasting.

12

Long-term analysis of air temperatures variability and trends on the Romanian Black Sea Coast

Bosneagu Romeo, Lupu Carmen Elena, Torica Emil, Lupu Sergiu, Vatu Nicolae, Tanase Viorel Mihai, Vasilache Camelia, Daneci-Patrau Daniel, Scurtu Ionut Cristian

Acta Geophysica

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2022

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Vol. 70, no 5

2179--2197

EN

Air temperature is one of the most important parameters that contribute to weather variability over time, being influenced by the flow of solar radiation, the general circulation of currents in the atmosphere relief. The present paper analyzes the minimum, maximum, and mean temperatures in Dobrogea, on the Romanian Black Sea coastal area, aiming to illustrate their evolution, which is a precondition for sustainable development in this region, from the perspective of regional and global climate changes. The weather stations included in this study are Constanta, Mangalia, Gura Portitei, Sfantu Gheorghe, and Sulina. The Pettit Test and the Standard Normal Homogeneity Test were used to determine changes in the evolution of the air temperature. For the period 1990–2020, the analysis of the change points, with a 95% confidence level, shows a particularly interesting situation supporting the general evolution of air temperature at global level. Nonparametric tests including linear regression, Mann–Kendall, and Sen's slope tests were used to analyze trends for monthly, seasonal, and annual series. Results showed an increasing trend in the annual minimum, maximum, and mean temperatures in all five weather stations.

13

Soft-bottom crustacean fauna from the Turkish coast of the Black and Marmara seas with new records

Mulayim Aysegul

Oceanological and Hydrobiological Studies

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2021

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Vol. 50, No. 1

60--76

EN

It is becoming increasingly important to monitor zoobenthic biodiversity in seas that are under industrial and anthropogenic pollution pressure, such as the Black Sea and the Marmara Sea. This study covers crustacean species in the Turkish waters of the Black Sea and the Marmara Sea, both of which are closed systems. Sampling was carried out in July–August 2019 and yielded 32 crustacean species from the Black Sea and 77 species from the Marmara Sea. In the Marmara Sea, two species [Kupellonura mediterranea and Leucon (Macrauloleucon) siphonatus] represent new records for the Turkish waters, and 12 species [Cirolana cranchii, Cumella (Cumella) pygmaea, Cyathura carinata, Cymodoce truncata, Eurydice pulchra, Gammaropsis sophiae, Harpinia truncata, Iphinoe serrata, Iphinoe trispinosa, Liocarcinus pusillus, Nebalia strausi and Synchelidium maculatum] are new to the Marmara Sea. The following species: Gammaropsis palmata, Pontocrates arenarius, and Synchelidium haplocheles are new records for the Black Sea. The order Amphipoda dominated in both seas in terms of the number of species and the number of individuals.

14

Determination of functional structure of soft-bottom marine macrobenthic communities of the Samsun Shelf Area using biological traits analysis

Van Ayşe, Gümüş Aysun

Oceanological and Hydrobiological Studies

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2021

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Vol. 50, No. 4

473--487

EN

Biological Traits Analysis (BTA) was used to investigate the functional structure of marine macrobenthic communities along the Samsun Shelf Area (SSA). Benthic samples were collected seasonally from five different locations and at four different depths using a Van Veen grab sampler. Macrofaunal communities distributed in the SSA were assessed using 10 biological traits to identify characteristic traits for each depth and location. It was found that variability of benthic ecosystem functions in the SSA was driven by biological traits such as maximum size, living habit, sediment position, feeding mode and type of reproductive behavior. Bivalves, polychaetes and crustaceans of small to medium size, biodepositing, burying themselves in the sediment (burrowers) and feeding in suspension were relatively more abundant at depths of 0–60 m. However, the biomass of Amphiura, Abra, Papillicardium and some polychaetes characterized by medium to large sizes, diffusive mixing, free living and feeding on deposit and subsurface deposit showed higher values at depths below 60 m. In general, it is concluded that the functional structure of the benthic infauna in the SSA has adapted to physical disturbance, and communities distributed in this area consist mainly of taxa resistant to mechanical pressure.

15

An Introduction to Polish-Turkish Relations in the Context of European Security

Yurdatapan Arda

Kwartalnik Bellona

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2021

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Nr 4

39--52

EN

This article is an introduction to the analysis of a bilateral relationship between Poland and Turkey, with particular focus on its influence on Europe’s security. Since this relationship is not an isolated one, we have to take into consideration the main actors having a geopolitical interest in the region between the Baltics and the Black Sea as well as the Middle East and their potential to influence Polish-Turkish relations to their own benefit. It seems that a geopolitical relationship between Poland and Turkey has the potential to influence the relations of other actors in order to favor peaceful stabilization and increase security in the region. However, one has to take into account the reactions of current partners of both states, since the consequences of a strategic Polish-Turkish alliance would be manyfold for nations in closer as well as wider geopolitical context. Such political factors as geographical barriers, cultural and religious differences, conflicting interests of other regional players or unexpected socio-political developments might serve as disruptive tools against which both, Poland and Turkey, would have to counteract actively and systematically. The benefits of the Polish-Turkish alliance - not only for Poland and Turkey, but for the entire region - seem to significantly outweigh its potential disadvantages. The increased security in the region is a major stabilizing factor that paves the way for a long-term sustainable socio-economic progress in all Europe.

PL

Artykuł jest wstępem do analizy relacji bilateralnych między Polską a Turcją, zwłaszcza pod kątem ich wpływu na bezpieczeństwo Europy. Relacje te należy ujmować z uwzględnieniem także głównych aktorów geopolitycznie zainteresowanych regionem między Bałtykiem a Morzem Czarnym i Bliskim Wschodem oraz możliwości wpływania przez nich na stosunki polsko-tureckie w aspekcie własnych interesów. Jak się wydaje, stosunki geopolityczne między Polską a Turcją zaczynają sprzyjać pokojowej stabilizacji i zwiększeniu poziomu bezpieczeństwa w regionie. Należy brać pod uwagę jednak reakcje dotychczasowych partnerów obu państw, ponieważ konsekwencje strategicznego sojuszu polsko-tureckiego mogą dotyczyć zarówno narodów bliskiego sąsiedztwa, jak i szerszego kontekstu geopolitycznego. Takie czynniki polityczne jak bariery geograficzne, różnice kulturowe i religijne, sprzeczne interesy innych regionalnych graczy lub nieoczekiwane zmiany społeczno-polityczne mogą być wykorzystywane jako narzędzia destrukcyjne, którym i Polska, i Turcja musiałyby aktywnie i systematycznie przeciwdziałać. Korzyści z sojuszu polsko-tureckiego - nie tylko dla Polski i Turcji, lecz także dla całego regionu - wydają się przewyższać jego potencjalne wady. Zwiększony poziom bezpieczeństwa w regionie jest bowiem czynnikiem stabilizującym, sprzyjającym długoterminowemu zrównoważonemu postępowi społeczno-gospodarczemu całej Europy.

16

Application of electrical resistivity tomography for imaging seawater intrusion in a coastal aquifer

Niculescu Bogdan Mihai, Andrei Gina

Acta Geophysica

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2021

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Vol. 69, no. 2

613--630

EN

Following previous geoelectrical researches initiated in 2009 for the delineation and characterization of seawater intrusion in a freshwater aquifer of Sarmatian (late Middle Miocene) age, a subsurface imaging survey via 2-D electrical resistivity tomography (ERT) was conducted in 2019 on the outskirts of Vama Veche resort—Romanian Black Sea southern coast. The survey was organized in the framework of a feld camp sponsored by the Foundation of the Society of Exploration Geophysicists (SEG)–Tulsa, OK, USA, with participation of teams from the University of Bucharest—Department of Geophysics and the Geological Institute of Romania. A number of eight ERT profles with N–S, W–E, NNE–SSW, and WNW–ESE orientation and 155–315 m length were imaged with a SuperSting R8/IP instrument (Advanced Geosciences Inc.), using deployments of 32–64 electrodes at 5 m spacing, in Wenner, Schlumberger, and dipole–dipole array confgurations. The processing and interpretation of high-resolution ERT data indicated that the seawater intrusion, evidenced as very low resistivity (5–10 Ω m) anomalous zones starting at approximately 45–49 m depth, has advanced at least 500 m inland. The survey results also allowed the identifcation of a system of fractures or faults with an approximate NW–SE/WNW–ESE and, possibly, N–S orientation, that might have provided potential pathways for saline water intrusion.

17

Influence of the climatic variations in the wind waves parameters on the alongshore sediment transport

Divinsky Boris V., Kosyan Ruben D.

Oceanologia

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2020

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No. 62 (2)

190--199

EN

The purpose of this work was to analyze the influence of climatic variability of wind waves and swell parameters in the coastal zone on the sediment transport and to assess the contribution of the swell to the formation of alongshore fluxes. The object of research is the Anapa bay-bar (the Black Sea). Mathematical modeling has shown that in the Anapa bay-bar area the average annual wind waves and swell powers have significant interannual variability. For the period from 1979 to 2017, in the southern part of the bay-bar, there was a statistically significant decrease in the share of swell in the alongshore transport, directed from NW to SE, in the central part – an increase in the contribution of swell to the total sediment flow from SE to NW, in the northern part – probable increase in flows to NW and decrease – to SE. Such a dynamic is consistent, in general, with experimental observations of the processes of erosion and accumulation of beach-forming material along the Anapa bay-bar coastline. A separate description of the bottom sediment fluxes under the influence of wind waves and swell made it possible to explain the fluctuations of the coastline over a climatic period.

18

Imprints of atmospheric waves on the Black Sea surface in data of ocean color scanners

Evdoshenko Marina A.

Oceanologia

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2020

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No. 62 (3)

255--266

EN

Data from MERIS onboard Envisat and MODIS onboard Terra and Aqua for 15-16 May 2010 were used to study powerful imprints of atmospheric gravity waves (AGWs) on the western part the Black Sea surface. Two cold fronts crossed the sea following the warm front and caused the AGWs which modulated the sea surface. Imprints of AGWs appeared as stripes of alternating brightness, they had crest length more than a hundred kilometers and wavelength of units of kilometers. Wave amplitude of AGWs imprints, evaluated by a 90%-depth of light penetration into the sea at 490 nm z90, the value inverse to the diffuse attenuation coefficient Kd_490, was units of decimeterxs. MODIS 250-m data of remote sensing reflectance, wind components and atmospheric pressure near the sea surface were obtained by processing the top of atmosphere data with the SeaDAS software package. Negative correlations of fluctuations of z90 with fluctuations of wind stress and atmospheric pressure were found on the transects of more than ten kilometers. The impact of wind stress on the origination of AGW imprints was found to be determinant, while the impact of atmospheric pressure was not more than units of percent.

19

Extreme wind waves in the Black Sea

Divinsky Boris V., Fomin Vladimir V., Kosyan Ruben D., Ratner Yuri D.

Oceanologia

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2020

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No. 62 (1)

23--30

EN

Results of the analysis of a long-term data set, including fields of significant wave heights of the surface wave components, and mixed (total) wave field in the Black Sea are presented. The data set was collected on the basis of retrospective calculations using the MIKE 21 SW spectral wave model with the atmospheric forcing based on the ERA-Interim data in the period from 1979 to 2017. A criterion is used to isolate the swell waves from the initial wave data set that takes into account the wave age. We used the experimental data to develop a regression relationship showing that the maximum possible wave height can exceed the significant wave height approximately one and a half times. Analysis of the spatial distribution of wave heights in the Black Sea suggests that a possibility exists that significant wave height of storm waves can be as high as ∼12 m. This result indicates that the actual heights of maximum waves in the Black Sea can reach 18-19 m. Three regions are distinguished on the basis of the wave potential. The times of manifestation of extreme situations in these regions are different: in the southwestern part of the sea, extreme storm situations occur, as a rule, in December-January; in the region south of the Crimea Peninsula this happens in February; in the northeastern part of the sea they occur in November. It was also found that the south-southeastern and eastern parts of the sea are most affected by swell.

20

Element enrichment and provenance of the detrital component in Holocene sediments from the western Black Sea

Dekov Vesselin M., Darakchieva Valentina Y., Billström Kjell, Garbe-Schönberg C. Dieter, Kamenov George D., Gallinari Morgane, Dimitrov Lyubomir, Ragueneau Olivier, Kooijman Ellen

Oceanologia

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2020

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No. 62 (2)

139--163

EN

Concentrations of a large set of major and trace elements, and Sr, Nd and Pb isotope ratios were measured in Holocene sediments cored in the western deep Black Sea in order to unravel: (1) the controls of element enrichment, and (2) sources of the detrital component. The transition of the basin from oxic to euxinic resulted in enrichment or depletion in a number of elements in the deep-sea sediments. Authigenic Fe enrichment appears to depend on the amount of Fe mobilized from the sediment through the benthic redox shuttle mechanism and free H2S in the water column (degree of “euxinization”). Manganese enrichment is controlled by diagenetic reactions within the sediment: the dissolution of Mn minerals, Mn2+ diffusion upward and reprecipitation. Barium enrichment is also controlled by diagenetic reactions, sulfate reduction and methanogenesis, that take place above and below the sulfate-methane transition, respectively. The major part of V, Co, Ni, Cu, Zn, Cr, Mo, Cd and Sb is inferred to have co-precipitated with Fe in the euxinic deep waters and to have been incorporated into authigenic Fe-sulfides. Basin reservoir effect additionally influences the Mo enrichment. The U enrichment is interpreted to have a different origin in the two organic-rich stratigraphic units (II and I). It is inferred to be: (i) at the expense of the U inventory of the deepwater pool and a result of inorganic reduction of U at euxinic conditions in the lower Unit II; and (ii) at the expense of the U inventory of the surface water pool and a result of biogenic uptake and transfer to the sediment by the plankton in the upper Unit I. The high field strength elements are closely linked to the detrital component and their depletion in the organic-rich sediments reflects a dilution of the detrital component by the biogenic one. The enrichments of REE, Sn and Th are likely controlled by adsorption on clay minerals. Sr-Nd-Pb isotope compositions of the alumino-silicate component of the studied sediments are relatively uniform. They are most likely controlled by riverine suspended matter supplied mainly in the NW Black Sea (Danube Delta) and transported southward by marine currents, and to a lesser degree by suspended matter from the small rivers draining SE Bulgaria and NW Turkey. Wind-blown dust from the Sahara Desert appears to have a minor contribution to the alumino-silicate component of the sediments. The slight shift in the Pb isotopes in Unit I upper layers is possibly caused by the addition of anthropogenic Pb.