First Find of Platinum in Cosmogenic Spherules of Ferromanganese Crusts (Fedorov Guyot,Magellan Seamounts,Pacific Ocean)

Doklady Earth Sciences - More than 250 magnetic spherules 40–200 µm in size were mechanically separated from a ferromanganese crust sample of Fedorov Guyot in the Magellan Seamounts. The...     

Mineral Composition of Manganese Crusts from Belyaevskii Volcano (Sea of Japan)

Doklady Earth Sciences - The polygenic mineral composition of Mn crusts from Belyaevskii Volcano of the Central Basin of the Sea of Japan is determined. The crusts are found for the first time to...     

Hypoxia of bottom waters of the Razdolnaya River estuary

The hypoxia of the bottom waters in the Razdolnaya River estuary was observed for the first time in September 2014 during the survey. It is formed as in the seaward part: oxygen is absorbed as a result of destruction of excessive phytoplankton biomass that settles to the bottom and is synthesized on the upper horizon. The high value of primary production in the riverine part of the estuary was caused by the pycnocline formed. Thus, phytoplankton “blooms” above and undergoes destruction beneath the pycnocline. Oxygen is distributed symmetrically in both parts of the estuary with respect to a bar: similar oxygen concentrations, which are maximum on the surface and minimum at the bottom, 300 and <60 μm/L, respectively, are recorded. The anomalies of hydrochemical parameters that have been formed during this process are sharply different in the two parts of the estuary, which most vividly manifests itself in the N/P value and the partial pressure of carbon dioxide pCO₂. The causes of this unique situation are discussed.

     

Ferromanganese crusts from submarine volcanoes of backarc basins as a new genetic type of gallium deposits

Study of the material composition of Fe-Mn crusts from submarine rises in the central part of the Sea of Japan, with modern precision methods applied, has yielded a high (up to 854 g/t) concentration of gallium contained in sorbed form. The new data obtained have allowed a new genetic type of gallium deposits—hydrothermal-sedimentary—to be distinguished.     

The first case of anoxia in waters of the Far East Marine Biosphere Reserve

In August 2013, anoxia of the bottom waters was established in the southern region of the Far East Marine Biosphere Reserve, Far East Branch, Russian Academy of Science, in the depression between Furugelm Island and coastal waters. Death of the benthic community was registered using a remotely operated underwater vehicle. The hydrochemical studies revealed that the area of the absence and/or presence of low oxygen contents corresponds to an area of anomalously high contents of ammonium, phosphates, and silicates, a high partial pressure of carbon dioxide and normalized alkalinity, and the presence of hydrogen sulfide. The microbiological decomposition of diatoms precipitated on the seafloor in the absence of oxygen regeneration was the reason for anoxia. Its formation in summer of 2013 was caused by anomalously abundant precipitates in the Far East.     

Algorithm for Calculating the Mineralization of Riverine Waters and Salinity of Estuarine Waters from Conductivity Data

Oceanology - The empirical relationship between the mineralization of riverine waters and specific conductivity normalized to 15°C was obtained in testing Razdolnaya River water from March...     

Water Dynamics and Structure in the Estuary of the Partizanskaya River (Nakhodka Bay,Sea of Japan)

Water Resources - Field studies of the seasonal and daily dynamics of the mixing zone were carried out in the microtidal estuary of the Partizanskaya River. The position of the mixing zone was...     

Diagenesis of Organic Matter in Eelgrass (Zostera marina L.) Vegetated Sediments

Oceanology - 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...     

Nature of Native Gold in Ferromanganese Crusts on the Seafloor of the Northwestern Pacific Ocean

Doklady Earth Sciences - SEM-EDS analysis of cobalt-rich Fe–Mn crusts (CRFMC) and their substrate rocks from the Gummy Bear seamount in the northwestern Pacific Ocean and the Magellan...