Biogeochemical characteristics of shallow methane seeps of Crimean coastal areas in comparison with deep-sea seeps of the Black Sea

Methane gas bubble emissions (seeps) are widespread phenomenon in the World Ocean, inter alia in Black Sea basin. The relevance of the research of methane seeps is due to their important role as a source of methane – greenhouse and environment-forming gas – for water column and atmosphere. The article presents a comparative analysis of the data from our biogeochemical 10-year studies of shallow gas seeps of the Crimean Peninsula and data on deep-sea gas seeps of the Black Sea. During 10-year period, apart from carrying out hydroacoustic research, the following parameters were determined: bubble gas component composition, methane carbon isotopic composition, microbial community structure of bacterial mats, covering gas bubble emission sites, and gas fluxes from separate seeps. During long-term monitoring, 14 separate gas bubble emission sites were detected and described in Crimean coastal areas; they were located from Cape Tarkhankut in the west of the peninsula to the Dvuyakornaya Bay in the southeast. Crimean coastal seeps were mostly of biogenic origin, with a seasonal type of gas bubble emission. Laspi Bay seeps were classified as emissions of deep gas of thermocatalytic genesis. A significant variation was recorded in values of isotopic composition of methane carbon δ13C-CH4 of bubble gas in coastal shallow areas (−94…−34 ‰), which indicates different conditions for bubble gas generation and maturation in seabed sediments. Similar to deep-sea seeps, coastal gas bubble emissions were accompanied by bacterial mats of diverse structure, with different dominating species. As shown, formation of stable bacterial biomass, usually consisting of sulfide- and sulfur-oxidizing bacteria, requires a fluid flux of reduced dissolved gases, while pointwise bubble gas discharge does not provide sufficient concentration gradients and can mechanically disrupt community structure. Various methods were used to estimate the size spectra of bubbles, as well as fluxes from separate seeps. Gas flux values varied from 1.8 L·day−1 (the Martynova Bay) to 40 L·day−1 (the Laspi Bay). The environment-forming effects, related to gas bubble emission in coastal areas, are discussed: effect of seeps on oxygen conditions in seabed sediments and in water column above gas emission sites, vertical water mixing due to gas lift effect, and fluid discharge at gas emission sites.

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Influx of streaming methane into anoxic waters of the Black Sea basin

Океанология ◽

10.31857/s0030-1574596952-963 ◽

2019 ◽

Vol 59 (6) ◽

pp. 952-963

Author(s):

Yu. G. Artemov ◽

V. N. Egorov ◽

S. B. Gulin

Keyword(s):

Spatial Distribution ◽

Black Sea ◽

The Black Sea ◽

Gas Bubble ◽

Dissolved Methane ◽

Anoxic Waters ◽

Deep Waters ◽

Methane Budget

Based on data on the spatial distribution and fluxes of streaming (bubbling) methane within the Black Sea, the rate of dissolved methane inflow to Black Sea deep waters was assessed. Calculations showed that gas bubble streams annually replenish the methane budget in the Black Sea by 1.2 109 m3, or 0.9 Tg, which is considerably less than determined by known biogeochemical estimates of components of methane balance in the Black Sea.

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The Transformation of Ottoman Policies toward the Ottoman Greeks during the First World War

The Young Turks' Crime against Humanity ◽

10.23943/princeton/9780691153339.003.0004 ◽

2012 ◽

Author(s):

Taner Akçam

Keyword(s):

Black Sea ◽

Important Change ◽

Coastal Areas ◽

Greek Population ◽

The Black Sea ◽

World War ◽

Black Sea Region ◽

The First World War ◽

Russian Military ◽

First World

This chapter examines how the policy followed against the Ottoman Greeks underwent an important change in November 1914, when the use of widespread violence against the Greeks and their forcible expulsion to Greece were halted. Policies concerning the Greeks during the war years were restricted henceforth to sending some of those living in coastal areas to interior provinces for military reasons. This procedure, connected with Russian military victories at the end of 1916 and throughout 1917, was carried out in a systematic manner, particularly in the Black Sea region. In some areas, massacres of Greeks were observed, but in general the Greek population remained exempt from the policy of deportation and annihilation applied to the Armenians.

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Deep-sea basin of the Black Sea and its mountain-folded framing

THE BLACK SEA SYSTEM ◽

10.29006/978-5-91522-473-4.2018.23 ◽

2018 ◽

pp. 23-33

Author(s):

N.V. Koronovsky ◽

Keyword(s):

Black Sea ◽

Deep Sea ◽

The Black Sea

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The Investigation of Sinop Coastal Area Pattern in Terms of Coastal Management

Environmental Management and Sustainable Development ◽

10.5296/emsd.v6i2.11241 ◽

2017 ◽

Vol 6 (2) ◽

pp. 85

Author(s):

Oylum Gokkurt Baki ◽

Osman Nuri Ergun

Keyword(s):

Land Use ◽

Black Sea ◽

Coastal Management ◽

Coastal Area ◽

Coastal Areas ◽

The Black Sea ◽

Black Sea Region ◽

Coastal Land Use ◽

The City ◽

Coastal Land

Sinop is a province located at the Black Sea region and it is rich in scenic beauty and cultural values and has potential touristic resources. Moreover, it is one of the most prominent port towns in the Black Sea region. The area, which can be qualified as the most important and prominent image region of the city, comprise the coastal land use line of the province. However, the city fails to utilize this advantage. The master plan of the city has substantially changed through the years. The present study aimed to determine the changes in the master plans of the city through the years, the distribution of the coastal land use areas and changes in the utilization of the coastal areas through the years. Evaluating the current administrative competence/constraints in the coastal area with respect to the data obtained in the study is also among the goals of the study. Furthermore, by taking the impact of environmental factors on the ratio of the land use areas into consideration, examining these data in terms of coastal management planning to create habitats that better suit the vital requirements is another prospect of the study. In addition, the evaluation of some coastal area-associated issues including the extent of the effect of current erosion issues on the development of the coastal area was also included in the study. The percentage of the current functional coastal areas in the province, the distribution of the number of building floors and the changes in these data by years were also investigated. For these evaluations, zoning revisions and 1/2000, 1/5000 and 1/10000 maps were examined to determine the coastal area zoning changes and filling areas. Fieldworks were carried out in the coastal area of the city to determine and observe the state of the area. The data was collected by contacting relevant institutions and organizations and carrying out fieldworks. Considering the data obtained in the study, measures to remedy the zoning deficiencies in the coastal area and the city center were proposed. The obtained data and evaluations obtained revealed that the province is in need of new and sustainable planning and there is a necessity to include implementations that are based on integrated coastal area management principals.

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