Morphostructural Analysis and Seabed Shelf Typing

Analysis of the morphometric characteristics from a study of the Barents Sea seabed has shown that the existing troughs are consistent with geodynamic conclusions, allowing morphological typing into structural slopes and reconstruction of their origin. Thus, the Norwegian–Mezenskaya rift system and Svyataya Anna and Victoria troughs were formed due to stretching of the lithosphere. The South Barents and Medvezinsko- Edzinskaya depressions formed at the generation stage of lithospheric plates due to the collision of several island arcs between outliers of the ancient oceanic crust. The choice of the geomorphic method for studying the seabed is because the science of geomorphology comprehensively studies bottom relief (morphology), its origin, and age. Adequate reconstruction of the causal relationships of exogenous and endogenous processes aids in substantiating the prediction of probable catastrophic seabed events. The results of mathematical calculations have confirmed the geodynamic conclusions within the Barents Sea region.     

Cretaceous–Early Cenozoic Geodynamics of the Olyutorka–Kamchatka Accretionary Zone

Doklady Earth Sciences - Within the Olyutorka–Kamchatka accretionary zone, several terranes of an island-arc, marginal-sea, and oceanic nature are distinguished. The igneous complexes of...     

Pelagic Ecosystem of the Nansen Basin under the Influence of Variable Atlantic Water Inflow: The Mechanism Forming Diatom Bloom in the Marginal Ice Zone

Doklady Earth Sciences - Unique data were obtained on the abnormally high level of phytoplankton biomass (30 g m–3) in the marginal ice zone of the deep-water High Arctic (the Nansen Basin,...     

Model Assessments of the Environmental Risk for Arctic Shelf Ecosystems in the Development of Resources

Doklady Earth Sciences - A method is proposed for assessing the environmental risk to the Arctic shelf. The method is based on a probabilistic model that makes it possible to combine the natural...     

New data on seismicity of the middle Caspian Basin and their possible tectonic interpretation

Short-term (three months) bottom seismic observations in the area of the Yalam-Samur structure in the Middle Caspian Basin revealed a deep-seated compact zone of mantle-earthquake sources that dips beneath the southeastern Caucasus. To a first approximation, this zone may be interpreted as a seismofocal layer that characterizes thrusting of the Turan Plate under the southeastern Caucasus. However, the obtained spatial distribution of sources of microearthquakes and weak earthquakes is insufficiently reliable owing to the low aperture of the observation network of bottom seismographs. More reliable data on the position and parameters of the seismofocal layer could be obtained by the observation network with a wider spread of bottom seismographs (up to 50–100 km). If this result is confirmed, the current concept of interaction between the Alpine structures of the southeastern Caucasus, Turan, and South Caspian plates should probably be revised. The geotectonics of the Caucasus is preliminarily analyzed in the light of the newly revealed relationships.     

New data on the subaerial low-center-polygonal relief and factors controlling its transformation and current state on the East Siberian Shelf

The problem of the current state of subaerial morphosculptures on the periglacial East Siberian Shelf is still debatable due to the lack of in situ data. Therefore, any new information contributes to the knowledge of the evolution of the Arctic environment. In view of this, a complex of interdisciplinary oceanological studies was carried out in the southeastern part of the Laptev Sea. Using a side-scan sonar, images of the bottom surface were made, which show the shape of low-center-polygonal relief of the part of the modern coastal lowland area in the coastal zone near the area under study. Possible factors controlling the state of this morphosculpture within the East Siberian Shelf area of interest are considered.     

A mathematical model of gas outflow from gas-saturated ice and gas hydrates

This paper considers gas outflow from the agglomerate composed of gas-saturated ice, free gas, and gas hydrates. The agglomerate is considered to be a multicomponent continuous medium.     

Ore potential of the Marcus-Wake rise (Central Pacific)

The data on the geological structure of different guyots on the Marcus-Wake rise with cobalt-bearing Fe–Mn crusts are discussed. Crusts are represented by three-layer aggregates composed of one lower phosphatized (I-1) and two upper non-phosphatized (II and III) layers. Fe-vernadite and Mn-feroxygite are the major ore minerals in all studied crusts and their layers. Small contents of vernadite, asbolane–buserite, and goethite are registered. Crusts of guyots on the rise are characterized by a stable concentration of heavy and rare metals (Co_tot, Ni, Cu, Zn, Pb, Mo, and Cd) independently of their latitudinal location.     

Seismotectonic Deformations Related to the 2011 Tohoku Earthquake at Different Stages of the Seismic Cycle,Based on Satellite Geodetic Observations

Doklady Earth Sciences - The data of multiannual satellite geodetic observations before, during, and after the 2011 Tohoku earthquake are interpreted on the basis of the keyboard model of the...     

Bitumoids of Holocene Sediments in the Barents Sea

Doklady Earth Sciences - The results of studying the content, composition, and distribution of chloroform bitumoids (CBs) in the Holocene sediments of the Barents Sea (cruise 68 of the R/V Akademik...