The influence of crustal rheology on plate subduction based on numerical modeling results

Computer simulation of subduction was performed using nonlinear equations of deformable solid mechanics encompassing all types of nonlinearity: geometric, physical, and contact. This study presents a numerical model of subduction with allowance for the gabbro-to-eclogite phase transition. The model rheology is a plastic compressible material (Mohr-Coulomb law for a deformed rock material). It was shown that deep subduction can be modeled well with the selection of appropriate parameters of rock plasticity providing the initial thickening in the subducting slab nose.     

Modeling the Regional Influence of Ions on Aerosol Formation in the Atmosphere

Izvestiya, Atmospheric and Oceanic Physics - The results of numerical calculations of the variability of number concentrations of aerosol particles of different sizes and the rates of ion-induced...     

Dynamical phases of intrasecular cycles of morphogenesis within the drainless lake basins of Dauria

A case study is made of the functioning of the Lake Khara-Nur drainless basin to gain a more penetrating insight into the mechanism of morphogenesis in the immediate vicinity of the cryogenic and arid morphoclimatic zones. It is shown that an alternation of dynamical phases of morphogenesis causes a matter redistribution between the elements of the basin system and the environment and leads to intense planation in the steppes of Central Asia.     

Use of digital terrain models in morphometric analysis of tectonic structures and prospecting of placers of alluvial genesis

Approaches have been developed to the application of the geomorphometric method for identification of neotectonic structures from maps of datum and summit planes by using the territory of Perm krai as an example. We carried out a comparative analysis of the resulting maps with existing neotectonic maps of local uplifts to reveal their good correlation. We substantiate the possibility of using the suggested approaches in forecasting deposits of sand-gravel raw materials.     

A New typification scheme of postsedimentation transformations of terrigenous deposits of continents and their margins with allowance for geodynamic factors

Previous studies of postsedimentation and deep rock transformations (the diagenetic, catagenetic, and anchimetamorphic stages) by the author and other Russian lithologists are revised by evaluating the different types of zoning of authigenic mineral formation within terrigenous complexes of different ages in definite structural-tectonic units of continents and their margins. It was emphasized that an intrarock aqueous fluid phase played a dual role in authigenic mineral formation: (1) it served as a medium for internal redistribution of sedimentogenic components or (2) as a carrier of external material. Indicator features of its own newly formed (A ₁) and allogenic (A ₂) authigenic minerals are given. It was shown that the background subsidence lithogenesis (SL) of the sedimentary sequence provides the formation of A ₁ varieties in the sequence, whereas the prevalence of A ₂ marks the superimposed or secondary alterations (SAs) of sedimentary rock. A combination of SL and SA features is demonstrated for different structures: syneclises and anteclises of cratons, rifts, fore troughs, orogens, and others. The SL and SA formation is determined by definite numerous exogenic and endogenic factors, which are often obliterated but integrated by geodynamic settings and geological evolution of sedimentary complexes. According to this conclusion, a new typification scheme of post-sedimentation transformations was proposed on the paleogeodynamic basis.     

The virial mass of the nucleus of M32

By means of the virial theorem we derive the dependence of the mass of an oblate spheroid in solid body rotation from the velocity dispersion and the space light density. The latter is obtained from a calibrated and seeing deconvolved brightness profile as numerical and stable solution of the Abel integral equation. The application of the nucleus of M32 gives a central density of 2.1×10^?5 M _⊙ pc^?3, a nuclear mass of 4.3×10^?7 M _⊙ and a mass-to-light ratio of 4.6 inV-band.     

Dynamics of the Middle Holocene Paleoclimate in the Steppe Zone of the Eastern European Plain According to the Data of the Study of Soils Buried under Mounds of the Bronze Epoch

Doklady Earth Sciences - Soils buried under archaeological monuments of the Bronze Age were studied on three test plots in Orenburg oblast, Stavropol krai, and Krasnodar krai. Kurgan 1 of burial...     

Spreading of Technical Oils and Crude Oil on the Water Surface

Doklady Earth Sciences - A mathematical model of oleic spot propagation based on the laws of conservation of mass and the total energy of the system is constructed. Compact solutions of this model...     

Bioaccumulation depuration kinetics and effects of benzo(a)anthracene on Mytilus galloprovincialis

Polycyclic aromatic hydrocarbons (PAHs) are important environmental pollutants due to their persistence and bioaccumulation potential both in organisms and in sediments. In this study, bioaccumulation and depuration experiments were performed employing local Mediterranean mussel species, Mytilus galloprovincialis, with two biomarkers: filtration rate and lysosomal stability (neutral red retention) assay. Benzo(a)anthracene (BaA) was chosen as the model PAH compound due to its common presence in several matrices in the marine environment. Bioconcentration Factors (BCFs) for the mussels exposed to different BaA concentrations were calculated from both kinetic rate constants and from the experimental data and found between 27-3184 and 16-2745, respectively. Experimental QSAR values were found comparable to the previous QSAR models created for BaA. The effect of BaA exposure on the mussels showed a more clear dose-response relationship according to the results of lysosomal stability compared to the filtration rate.     

Applying the energy- and water balance model for incorporation of the cryospheric component into a climate model. Part II. Modeled mass balance on the green land ice sheet surface

The Greenland ice sheet is a very important potential source of fresh water inflow to the World Ocean under warming climate conditions. Apparently, it was the same during the Last Interglacial 130-115 thousand years ago. In order to quantify input of the Greenland ice sheet to the rise of the global mean sea level in the past or in the future, we include a surface mass balance model block into the Earth System Model. The computational algorithm is based on the calculation of energy balance on the ice sheet surface. The key tuning parameter of the model is the daily amplitude of air surface temperature. It defines the area and the rate of snow or ice melting. The range of possible values of this parameter is determined during a series of numerical experiments. High sensitivity of meltwater runoff volume to surface air temperature amplitude is revealed.