Seasonal Changes of the Bottom Sediments’ Physicochemical Characteristics in the Region of the Near-Coastal Methane Seeps

Physical Oceanography

S.K. Konovalov¹  M.A. Myslina¹  K.I. Gurov¹ 

[1] Marine Hydrophysical Institute, Russian Academy of Sciences, Sevastopol, Russian Federation;

关键词: crimea;    tarkhankut peninsula;    methane seeps;    bottom sediments;    granulometric composition;    organic carbon;    carbonate content;   

DOI  :  10.22449/1573-160X-2018-2-136-143

来源: DOAJ

【 摘 要 】

The features of seasonal changes in physical (moisture, granulometric composition) and chemical (organic carbon content and carbonate content) characteristics of the bottom sediments in the region of the coastal methane seeps in the southern sector of the Tarkhankut Peninsula are investigated. It is shown that the bottom sediments of the region under study are represented by fine- and medium-grained sand containing inclusions of aleurite-pelitic silts and shell detritus. The obtained in situ data on the content and vertical distribution of Corg and CaCO3 in the bottom sediments make it possible to examine the intra-annual dynamics of the basic geochemical parameters in the areas of the methane gas hydrates and to assess influence of the methane seeps upon the geochemical structure of the bottom sediments. The values obtained for the period under investigation can be divided into three parts: before formation of the bacterial mass (May), the period of maximum formation of mat (June – September), the time of destruction of the mat structures (November). It is shown that in May before the mat structures are formed, the Corg content in the surface 0–2 cm layer is low (0.5 %), in June it increases up to 15.5 %, then decreases to 9.7 % in September and to 2.3 % in November. In the surface layer, the CaCO3 content is maximal in late May (93.5 %); during the mat formation in June it decreases to 16.6 % and then grows from 23.5 to 49.1 % in August – November, respectively. Being analyzed, the data on vertical distribution of the geochemical characteristics under study show that accumulations of the bacterial mats affect the intra-annual variation of the above-mentioned parameters.

【 授权许可】

Unknown