Geochemical anomalies in South Caspian sediments

Study of the element composition of ten samples of modern terrigenous and carbonate sediments from the northern part of the Caspian Sea by the ICP-MS method showed that these sediments were enriched in sulfur, nonferrous metals, and some related minor elements including Se, Te, Re, and others in comparison with the average composition of sedimentary rocks. It is assumed that local hydrothermal seeps similar to those known on the Cheleken Peninsula and which may be formed in other areas of this tectonically active zone are the sources of these elements. In addition, such a composition of sediments may indicate the sporadic contamination of bottom water with hydrogen sulfide, which has been observed in areas of the South and Middle Caspian by many researchers.     

Distribution of hydrocarbons in water and bottom sediments of the Northern and Middle Caspian Sea

A study of two classes of hydrocarbons (HCs)—aliphatic and polycyclic aromatic—in suspended matter of the surface waters and bottom sediments of the Northern and Middle Caspian Sea (R/V Nikifor Shurekov, October 2015) is described. It has been determined that oil pollution transported by river runoff and fluid streams flowing from sedimentary formations in the northeastern part are the main sources of hydrocarbons in the river–sea boundaries of the Volga, Terek, and Sulak rivers.     

Pattern of large raised bog formation in the South-Eastern Baltic Region during the Holocene: the case of Kaliningrad oblast

The results of complex investigations that have been carried out since 2007 in large bog ecosystems (Zehlau, Bolshoe Mokhovoe, and Koz’e) located in Kaliningrad oblast in two largest landscape areas, glaciolacustrine plains in the central part of the region and coastal lowlands of the southern coast of Curonian Lagoon and the delta of the Neman River, are presented. It is established that the intensive development of mires and their transition to the raised bog stage occurred in the territory of Kaliningrad oblast later than in most of the forest zone in European Russia, where this process was noted as early as during the Atlantic. On the glaciolacustrine flat plains in the central part of Kaliningrad oblast, where there were no deep depressions, the mire formation process was manifested weakly for a long time. A colder and more humid climate, which is a condition necessary for the raised bog peat accumulation and rapid expansion of bogs to the adjacent forest area, occurred only in the Subatlantic.     

The Biological Calcium Carbonate Pump in the Norwegian and Barents Seas: Regulation Mechanisms

Doklady Earth Sciences - This paper reports on a study of the phytoplankton calcium carbonate pump in the Norwegian and Barents seas in July–August 2017. Coccolithophores, a unique marine...     

The North Pole Region: First Data on the Snow–Sea Ice–Ice Water Sedimentation System

Doklady Earth Sciences - The dispersed sedimentary material in the snow–ice cover near the North Pole was analyzed directly for the first time. The composition of sediments in the...     

The Energy Spectrum of the Current Velocity in the Deep Part of the Black Sea

Doklady Earth Sciences - In 2016–2017, the yearly long measurements of the current velocities were carried out at 100 m depth below the thermocline and at 1700 m depth for the first time,...     

Relationship between the suspended particulate matter and microorganisms in the White Sea waters

During the summer periods of 2003–2005, the spatial and vertical distributions of the suspended particulate matter and bacteria in stratified and homogeneous waters of the White Sea was studied. The results of the study of various quantitative characteristics of the suspended particulate matter (first of all, the area of the surface and the volumetric and mass concentrations) and the abundance of microorganisms in the water are discussed. A direct correlation between the value of the surface area of the suspended particulate matter and the total number of bacteria in the water is revealed. However, it was manifested only during the early summer period of the observations and was not expressed at the end of the summer. The enhanced surface area of the suspended particulate matter can indicate the higher biochemical activity of its particles. The influence of the pelitic fraction on the bacteria abundance in different parts of the sea during the summer is estimated.     

Studies of Sediment Systems of the European Arctic during Cruise 75 of the R/V Akademik Mstislav Keldysh

Oceanology - Abstract—The paper presents the results of systemic oceanological studies of the European part of the Arctic during cruise 75 of the R/V Akademik Mstislav Keldysh. The expedition...