Abstract The 49th cruise of the R/V Akademik Sergey Vavilov (August 29–September 7, 2019) allowed to obtain new data on the Baltic Sea geological history and the current state of its ecosystem under eutrophication conditions. The size and shape of the Gotland contourite drift, as well as the Major Baltic inflow pathway in the Baltic Proper were specified. The conditions of hypoxia and anoxia in combination

Abstract New data on the formation of the bottom topography, bottom sediments, spatial structure and dynamics of waters of the Baltic Sea were obtained in cruise 42 of the R/V Akademik Nikolaj Strakhov (August 17–27, 2019). The distribution, morphology, and structure of large sand bodies on the Rybachy plateau were obtained. Additional data on the formation of the bottom topography and sedimentation

Abstract Geological, hydrological, hydrochemical, and biological research has been carried out in the eastern tropical Atlantic. Based on the multibeam echo-sounding and seismic profiling north of the Kane Gap (Sierra Leone Rise), an extensive sedimentary body (contourite fan) has been identified. Data of hydrophysical sounding allows assuming the existence of an overflow of the Antarctic Bottom Water

Abstract The first sampling of mantle horizons underlying the ophiolite peridotite complex of the Mariana back-arc basin was carried out based on a spinel lherzolite xenolith in basanites from the submarine Esmeralda Volcano. The paper shows significant differences between the bulk, petrological, geochemical, and mineralogical compositions of this xenolith and similar characteristics of ophiolite peridotites

Abstract It is proposed to use data on the hydrocarbon content in phytoplankton contained in a studied water sample to calculate the biogenic background of hydrocarbons, without which the assessment of the degree of oil pollution of aquatic ecosystems would be incorrect. Algae were grown in sterile flasks to accumulate the biomass required for analysis. The amount of hydrocarbons isolated from lipid

Abstract— Samples were collected in the area of the St. Anna Trough in the northern Kara Sea in September 2015 and July–August 2016. Based on salinity and temperature distribution, four areas have been distinguished: the shelf adjacent to the St. Anna Trough, the shelf edge, and the upper and lower parts of the continental slope. The variability of the structure of phytoplankton communities has been

Abstract Analysis of zooplankton collected on five cruises (2007–2016) in the Kara and Laptev seas has revealed considerable heterogeneity in the spatial distribution of the biomass of the pteropod Limacina helicina, one of the important components of the Arctic zooplankton. The biomass and abundance of mollusks in 2014–2016 were significantly lower than in the previous period, in 2007 and 2011. The

Abstract Data on temporal (July and September) and interannual variations in the content of several heavy metals are presented for the body wall, gonad, and gut of the sea cucumber Eupentacta fraudatrix from coastal waters of two inlets of Peter the Great Bay (Sea of Japan) with different levels of anthropogenic pollution. The gonads mostly accumulate Zn, Fe, Cu and Cd, while the body wall, presumably

Abstract This paper reports the results of investigations in September 2017 on the radioecological state of bottom sediments of the East Siberian Sea during integrated research of the Siberian Arctic seas on cruise 69 of the R/V Akademik Mstislav Keldysh. Evaluation of the results of γ-spectrometric analysis found that the current specific activity of artificial cesium-137 in sediments is two orders

Abstract We studied sedimentation processes in the Lofoten Basin of the Norwegian Sea based on data of the Automatic Deep-Sea Sedimentation Observatory (ADSO) deployed for a year (August 2017–July 2018). The article presents estimates of the vertical fluxes of total sedimentary material, organic carbon (Corg), calcium carbonate (CaCO3), biogenic silica (SiO2bio), aluminum, and the particles of planktonic

Abstract Picophytoplankton abundance, biomass, and chlorophyll a concentration as well as contribution of picoalgae to total chlorophyll a, and species composition of phototrophic picoeukaryotes (cells size less than 3 µm) were studied in Blagopoluchia Bay (Novaya Zemlya archipelago) and the northwestern part of the Kara Sea in September 2017. In the Bay, the highest picophytoplankton abundance and

Abstract Shelf currents are formed by the wind, tides, and pressure gradient. Wind is usually the dominant energy source for coastal currents. This paper considers the formation of the coastal current under the effect of push-off wind and its influence on the thermohaline structure of Peter the Great Bay waters. When wind increases, a strong coastal current forms along the isobath and a transverse

Abstract A study of abrasive rock destruction at different horizons of the littoral zone in Dalnezelenetskaya Bay (Murmansk coast) was carried out. It is revealed that the abrasion rate of coarse-grained material in 2012–2018 on average was 40 ± 4 μm g–1; the average destruction rate of blocks was 49 ± 4 μm g–1; boulders, 22 ± 3 μm g–1. On the whole, in 2012–2018, a decrease was observed in the rate

Abstract The recent coastal dynamics of Varadero resort located on the Hicacos Peninsula (northern Cuba coast) demonstrate a trend of progressive beach erosion and degradation. This paper proposes an approach to coastal protection based on creating an artificial beach that should withstand extreme storm impact. The parameters for protecting a beach composed of biogenic sand (the most available material

Abstract The paper describes a two-layer model of substance transport in waterbodies, in which relatively deep regions exist together with large shallow-water regions. The model combines hydrodynamic and transport components. Equations with corresponding boundary conditions are given. The problem is solved using finite-difference methods on a uniform rectangular grid. Model examples of solid runoff

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 covered the waters of the Norwegian, Greenland, and Barents Seas. The main goal was a conjugate study of dispersed sedimentary matter (atmospheric aerosols, water suspended particulate matter), and bottom sediments with an

AbstractHerein we provide information on the integrated geological, geophysical, sedimentological, paleoceanographic, hydrophysical and biological investigations in the Central Atlantic during the cruise 45 of the R/V “Akademik Nikolaj Strakhov” in October-November 2019. The preliminary scientific results are discussed.

Abstract—A model has been developed that explains sediment accumulation within a groin field from the aspect of mass conservation. The model revealed that intergroin sedimentation is related to the gradient of the adjacent longshore sediment transport. An important model parameter is the length Λ of the structure’s zone of influence. It is shown that the accumulation rate reaches its maximum when the

In February and July 2014, multidisciplinary geochemical studies of the sediments were carried out at two stations. One of them was located in Voevoda Bight, which has a bottom depth of 4 m, covered by eelgrass (Zostera marina L.); the other one served as a background station, because it is devoid of seagrass and is located in the northern part of Amur Bay (near Rechnoj Island). This station has a

The study reveals the distribution of contents of major (Si, Al, Fe, Mn) and trace elements (Ga, V, W, Th, Mo, U, Be, Y, Cd), Сorg, and clay minerals in the subcolloidal fraction of bottom sediments of the marginal filter of the Razdolnaya River (soil, river and marine sediments). Under the influence of increased river discharge as a result of a typhoon, the flocculation zone, the formation of Fe and

It is believed that the waters of rivers flowing into the Kara Sea (predominantly discharge of the Yenisei and Ob rivers) can propagate to the east, penetrating the Laptev Sea with the current along the coast. This can occur with the so-called eastern transfer of continental runoff. During a cruise of the R/V Akademik Mstislav Keldysh in 2018, traces of riverine waters were discovered in the Vilkitsky

The paper presents the first results of a study of seasonal variations in the grain size distribution and mineral compositions of suspended particulate matter (SPM) of the Northern Dvina River. The SPM samples were collected every month during 2016–2017 at the outlet of the Kuznetchiha arm to Dvina Bay of the White Sea. The grain size fractions were separated by Petelin’s water-mechanical method with

AbstractIn this paper, the distribution of polychaetes in the Laptev Sea and New Siberian shoal is analyzed based on 115 bottom trawl samples taken in August–October 2014. Polychaetes were the most species-rich group (83 taxa, 74 identified to the species level). Two faunistic assemblages of polychaetes, coastal and offshore ones, were distinguished. The boundary of their distribution did not coincide

The paper presents the general lithological and geochemical characteristics of subsea permafrost and thawed bottom sediments from three cores drilled in Buor-Khaya Bay. The lithological, organic chemical, and microscopic data revealed spatial differences of Quaternary sedimentation and sedimentary evolution, which are determined by riverine dynamics, cryogenic processes, coastal abrasion, and ice activity

Sea level changes during of Earth’s glacial periods the reduce hydrostatic pressure on the ocean bottom. The decrease in hydrostatic pressure increases magmatic activity and, as a result, could lead to the formation of hydrothermal systems [9, 19]. Thus, a correlation between glacial periods and the origin of circulating hydrothermal systems is possible. To test the hypothesis about the relationship

AbstractThe paper discusses the principles of developing a hierarchical system of units for zoning the coastal zone and shelf of the World Ocean based on bionomic (ecosystem) features are discussed. A number of scientific and applied problems require zoning of ecoregions (sea basins) at the regional and topological levels. A system of units is proposed, taking into account the zonal, depth-related

Field measurements carried out over 4 years made it possible to establish previously unknown features of the thermohaline fields and circulation of Lake Issyk-Kul. The most detailed salinity distribution maps for the entire history of observations were constructed. An area of slightly increased salinity was found in the central part of the lake, the specific “dipole” shape of which indicates the existence

The paper presents the results of grain size analysis of bottom sediments and subsea permafrost from three cores drilled in Buor-Khaya Bay. A pronounced lithologic differentiation of the studied terrigenous deposits were revealed, as well as a wide variety of grain size and genetic types of deposits accumulated in various natural environments. The most of investigated sediments are represented by alluvial

A new approach has been applied to studying marine sedimentation using dispersed sedimentary material in sediment traps compared to the surface layer of bottom sediments. Based on long-term studies of a small sea of the Arctic Ocean, it was possible to establish new sedimentary patterns in the conditions of the Subarctic and Arctic zones. The monthly, seasonal, and long-term dynamics of the main components

Abstract—The bay waters of the Sea of Okhotsk near the Shantar Islands are the most important summer grazing areas for bowhead whales (Balaena mysticetus) of the Okhotsk population. A hydrobiological survey during the period from July 12–28th, 2016, demonstrated that waters around the Shantar archipelago are characterized by high concentrations of humic substance supplied by the peat-laden banks of

Abstract—The article reports results of benthic research carried out in the Northwest Pacific in the Bering Sea using the remotely operated vehicle Comanche. The study concerns the distribution of dominant animals in the summit region and at the upper slope of four southern guyots of the Emperor Seamount Chain.

Abstract—The article briefly describes the results of integrated geological, geophysical, and hydrophysical studies on the shelves of the Barents and Kara seas. The research was aimed at substantiating the most probable scenario of development of natural conditions of Russia’s Western Arctic against ongoing climate warming, sea level rise, and increasing anthropogenic impact. Studies have confirmed

Abstract—The paper contains original data on the rock-forming and rare element compositions in the Pliocene–Holocene alkaline basaltoids of the Tsushima Basin Sea of Japan, obtained by the “wet chemistry” method, atomic emission spectrometry, and inductively coupled plasma mass spectrometry. Based on interpretation of these data, the geochemical and geodynamic features of this stage of volcanism were

Abstract—The paper studies carbon transformation and transfer processes in the crust and mantle. Sediments dragged into subduction zones are dewatered, broken down, and altered by metamorphic processes. Some carbon compounds are immersed in the sublithospheric mantle and transported by convective currents into the rift zones of mid-ocean ridges. There they are transformed again, forming new chemical

AbstractThe vertical distribution of phytoplankton primary production (PP) and chlorophyll a (Chl) was studied based on the data carried out in August–September 2015, 2017, and 2018. The PP maximum was located at the surface or within the 0–5 m subsurface layer. The subsurface chlorophyll maximum (SCM) was recorded at 39% stations on the outer shelf and in the vicinity of the continental slope. The

Abstract—The research is dedicated to the suspended particulate matter (SPM) distribution and the hydrological–hydrochemical conditions within the oceanic upwelling of the so-called Guinea Dome. This dome is a 500 km diameter stable cyclonic eddy, the center of which is located at 10° N and 22° W. It was formed owing to northern branch of Equatorial Counter Current activity. A cruise in November 2016

Abstract—The article considers the modern dynamics of Bakalskaya Spit (northwestern Crimea), the distal part of which separated in 2010, becoming an island. It is shown that in the last 200 years, the coastline to its east and west has retreated. Analysis of satellite data and geodetic surveys revealed that in the last 30 years, the distal part of the spit shifted northeast by 300 m and the western

AbstractThis paper considers the pattern of shore use by seals in relationship with the location of haulout sites, their geomorphological parameters, and the influence of oceanographic conditions. Spotted seals in the southern Sea of Japan, which are known to breed on shore, for pupping and nursing are found to only use spit beaches, barrier spits between two basement massifs, and attached beaches

Abstract—The 3D finite-element hydrostatic model QUODDY-4 is used to study the influence of horizontally nonuniform stratification on internal tides and their induced diapycnal diffusion in the ice-free Kara Sea. This model was used to perform two numerical experiments. In the first stratification is assumed to be horizontally uniform and determined by predicted seawater temperature and salinity values

Abstract—The trend of the recent development of the Anapa bay-bar is considered based on modeling of sediment transport and morphodynamic processes. It is shown that longshore sediment transport does not have a crucial influence on the coastal dynamics. Most coastlines undergo degradation despite accumulation due to unloading of the longshore sediment flux. The probable reason is the relative sea level

Abstract—Analysis more of 80 hydrocarbon fields, mainly oil-producing, in the deepwater part of the Santos, Campos and Espirito Santo basins reveal the tendency of these large fields to lie in a productive oil-pay belt extending in the sea depth from range from 400 to 2500 m (possibly 3000 m or more) in a system of external depressions stretching along the lower part of the continental slope. This

Abstract—The paper describes the composition of bottom and beach sediments of the large accumulation form (the Anapa bay-bar). It has been shown that the sand particles size increases in the direction from the edges of the bar to its center and from a depth of 7 m to the beach. When comparing the data of 2012‒2018, it can be seen that, on the whole, the size and composition of the sand have not changed

AbstractThe article describes a technique for studying the spatiotemporal variability of the temperature of the water medium in the Black Sea shelf zone using a cluster of anchored temperature sensor chains (thermoresister chains). The cluster consists of three spaced thermoresister chains situated on the inner shelf of the northeastern Black Sea and operating as a part of the Gelendzhik Site of the

AbstractIsotope studies (δD and δ18O) were performed for the glaciers of Severny Island (Novaya Zemlya Archipelago). The studied glaciers were characterized by narrow range-of δD and δ18O values (from –15.4 to –17.6 ‰ and from –110.9 to –127.1‰, respectively). The samples of glacier ice form a linear trend within the δD–δ18O coordinates with low slope (s < 7). The isotope signature of water runoff

AbstractThe paper presents a mass-balance model that simulates the biotic energy flux in the White Sea ecosystem. The model is designed to forecast the annual production of autotrophic organisms, decomposers, and consumers of various orders, including fish and marine mammals. The results are tabulated and include the biotic balance of the sea, i.e., the biomass and production of key groups of hydrobionts

Abstract—The large-scale expedition of cruise 76 of the R/V Akademik Mstislav Keldysh was performed by the Shirshov Institute of Oceanology from July 1 to August 6 2019 within the Program “Marine Ecosystems of the Siberian Arctic.” Seventy-one scientist from Russian Academy of Sciences institutes, Moscow State University, and VNIRO participated. Coordinated hydrophysical, hydrochemical, biooceanological

AbstractThe paper presents information on geochemical and mineralogical investigations of sedimentary rocks carried out in April 2019 in the Northern Morocco. A set of data on mineral and chemical composition of the Late Miocene deposits was obtained in the region of the contourite paleo-channel. The obtained results improved lithological description of the studied outcrops and confirmed the significant

AbstractThe coast of the shallow Azov Sea is characterized by a series of sand spits. Based on the results of drilling conducted on Dolgaya Spit, which separates the water area of Taganrog Bay from the rest of the Sea of Azov, we consider the structure of the upper part of the geological section of these coastal accumulative forms. Core samples obtained during drilling made it possible to determine

AbstractAccording to the Plan of Complex Scientific Research of the World Ocean for 2017–2022, the V.I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences, continues to study the northern part of the Sea of Japan and the Tatar Strait, carrying out a three-year plan of expeditionary research of this region. The expedition aboard the R/V Akademik Oparin (cruise

AbstractThe coefficients of selectivity of a nitrate-selective electrode to \({\text{C}}{{{\text{l}}}^{ - }}\), , and \({\text{SO}}_{4}^{{2 - }}\) ions were experimentally determined: 0.006, 0.0002, and 0.0003, respectively. The value of the activity coefficient of \({\text{NO}}_{{\text{3}}}^{ - }\) ions in seawater with 35‰ salinity was ascertained: 0.533 ± 0.011 at 25°C.

AbstractThe algae geochemical anomaly coefficient (KGA) and hazard coefficient (KMe), which are geochemical coefficients characterizing the condition of an algae habitat, have been calculated based on heavy metal (Fe, Mn, Cu, Zn, Pb, Cd, and Ni) levels in the brown alga Sargassum miyabei sampled at different time intervals from 49 stations in Peter the Great and Kievka bays, Sea of Japan. It has been

Abstract—In 2019, a new instrument was included in the multifunctional measuring complex at the Gelendzhik Research Site (Shirshov Institute of Oceanology, Russian Academy of Sciences, IO RAS), which allows automatic measurement of the hydrophysical parameters of the aquatic environment from the bottom layer to the surface of the waterbody with on-line transfer of data to the coastal center. This is

AbstractJoint analysis of wind wave characteristics derived from Voluntary Observing Ships data (VOS) and the third-generation spectral wave model WAVEWATCH III v.5.16 hindcast is presented. Global distributions of significant wave heights and mean periods in both datasets demonstrate good qualitative and quantitative agreement, especially in regions with a high spatiotemporal density of observations

AbstractThe present study examined the hydrochemical and biological parameters influencing the spatial distribution of bacterioplankton in the Laptev Sea and the East Siberian Sea shelf regions affected by the Khatanga, Indigirka and Kolyma rivers runoff during September 2017. The highest bacterial abundance and the amount of actively respiring bacteria were determined in rivers delta and in surface

AbstractStatistical analysis of heat flow distribution along nine geotraverses crossing mid-oceanic ridges in the Atlantic, Pacific, and Indian oceans is carried out. Significant asymmetry of heat flow distribution is established: its mean values differ on opposite sides of ridge axes. In geotraverses of the Southern Hemisphere, their western flanks have a higher average heat flow, and on geotraverses

AbstractStudies of the interannual variability of primary production, surface water temperature, photosynthetically active radiation, and sea ice cover in the Laptev Sea were performed based on MODIS-Aqua data (2002–2018). For a 17-year period, a statistically significant positive trend of surface temperature (R2 = 0.27) and a negative trend of photosynthetically active radiation (R2 = 0.24) were established

Abstract—Tidal ocean corrections for gravity observation play an important part in monitoring studies. Tidal ocean models were tested by Transcontinental Tidal Gravity Profile (TTGP) results. This part of the global tidal network was used for study the influence of the Atlantic and Pacific oceans up to coastline. Our tidal result agrees with static theory and had a weak ocean dynamic influence (Schiwiderski

Abstract—Materials collected in different seasons in the region of the Yenisei estuary, as well as previously published data, were used to analyze the scale and patterns of the seasonal variability of microbial communities. In all seasons concerned, three zones could be distinguished in the estuarine area based on the salinity values. The abundance and activity of bacterioplankton in these zones varied

Abstract—Based on average monthly data of the ORAS4 ocean reanalysis, the spatial distribution and values of anomalies of the ocean surface temperature and the velocity of surface currents occurring in the North Atlantic at the meridional displacements of the north wall of the Gulf Stream in January–February are determined. Gulf Stream North Wall Index data are used as data on Gulf Stream movements

Abstract—The results of acoustic sounding of the routes of underwater pipelines obtained by the authors in a number of expeditions in river water areas and in the seas of the Arctic Ocean are considered. The possibilities of using narrow-beam parametric systems as a component of environmental monitoring are discussed. in areas buried under the bottom of underwater pipelines.