The fishery for pelagic redfish (Sebastes mentella) in the Irminger Sea and adjacent waters     

Sigurthsson  Th.; Kristinsson  K.; Ratz  H-J.; Nedreaas  K.H.; Melnikov  S.P.; Reinert  J. 《ICES Journal of Marine Science》2006,63(4):725-736

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Phenomena caused by seismic and geocryological processes across linear infrastructure, South Yakutia, Russia     

L. Gagarin  A. Melnikov  V. Ogonerov  I. Khristophorov  K. Bazhin 《寒旱区科学》2017,9(4):352-362

High seismic activity, difficult permafrost and hydrogeological conditions of South Yakutia (Russia) complicate building and exploitation of engineering construction and require additional detailed and complex research. These conditions are evident within two sites. The first site is located in the middle reach of the Duray River, where it is crossed by the highway Lena. The second site is located on the right side of the Chulmakan River Valley, 400 meters to the east of the ESPO oil pipeline route. Seismic events, occurring four years ago, led to landslides in the mentioned sites. Formation of joint fissures on slopes assisted drainage of aquifers of free water exchange zone. It is worth noting that at the Duray River site, 59 cm of active soil slumping movement towards the roadbed has occurred within two summer months. Such a process is complicated by cryogenic disintegration of rocks in the base of the landslide body due to groundwater discharge and icing formation in winter.  相似文献   

Isotopic geochronology and biostratigraphy of Riphean deposits of the Anabar Massif,North Siberia     

T. S. Zaitseva  M. A. Semikhatov  I. M. Gorokhov  V. N. Sergeev  A. B. Kuznetsov  T. A. Ivanovskaya  N. N. Melnikov  G. V. Konstantinova 《Stratigraphy and Geological Correlation》2016,24(6):549-574

The structure of Riphean deposits developed on the western slope of the Anabar Massif is described with analysis of their depositional environments, distribution of stromatolite assemblages and organic-walled and silicified microfossils through sections, and evolution of views on stratigraphic significance of some of these assemblages. The investigation included complex mineralogical, geochemical, structural, and isotopic?geochronological study of globular phyllosilicates (GPS) of the glauconite?illite series from paleontologically well substantiated Riphean sequences (Ust’-Il’ya and Yusmastakh formations of the Billyakh Group) of the Anabar Massif in the Kotuikan River basin. Isotopic dating of monomineral size and density fractions of GPS from the Billyakh Group was performed in combination with simulation of the distribution of octahedral cations and comparison of the results obtained with Mössbauer spectrometry data. The applied approach is based on an assumption that the formation and transformation of Rb?Sr and K?Ar systems in GPS are synchronous with stages in their structural evolution, which are determined by the geological and geochemical processes during depositional history. Such an approach combined with the mineralogical and structural analysis contributes to correct interpretation of stratigraphic significance of isotopic data. The results obtained provide grounds for the conclusion that isotopic dates of GPS from the Ust’-Il’ya (Rb?Sr, 1485 ± 13 Ma; K?Ar, 1459 ± 20 Ma) and Yusmastakh (Rb?Sr, 1401 ± 10 Ma; K?Ar, 1417 ± 44 Ma) formations mark the stage of early diagenesis of sediments and are suitable for estimating the age of formations in question.  相似文献   

Estimation of atmospheric paleo-circulation based on isotope composition of ice wedges     

I. D. Streletskaya  A. A. Vasiliev  V. P. Melnikov  G. E. Oblogov 《Doklady Earth Sciences》2014,457(2):1025-1027

Cryostratigraphy of frozen late-Pleistocene sediments was studied in natural exposures at the Arctic coastal area. The isotope composition of ice wedges was determined. The data base on isotope composition of syngenetic ice wedges and modern elementary ice veins was compiled for the Eurasian Arctic based on obtained data and available literature sources. Spatial distribution of the isotope composition of ice wedges, which indicates paleo-climatic conditions, was determined separately for Marine Isotope Stages (MISs) from MIS 1 to MIS 4 for the Eurasian Arctic. The pattern of this distribution has remained stable during the last 50 000 years, which indicates a stable trend in atmospheric circulation from 50 000 yr BP to the present.  相似文献   

Seismic studies of frozen ground in Arctic areas     

V.P. Melnikov  A.G. Skvortsov  G.V. Malkova  D.S. Drozdov  O.E. Ponomareva  M.R. Sadurtdinov  A.M. Tsarev  V.A. Dubrovin 《Russian Geology and Geophysics》2010,51(1):136-142

Seismiv surveys have been applied to investigate the structure of frozen ground, to identify and contour natural and man-caused unfrozen layers in permafrost (taliks), to constrain the position of the permafrost table in the Arctic inner shelf, and to study the related coastal stability. They are the classic methods common in shallow seismic exploration and new techniques specially designed at the Institute of Earth’s Cryosphere (Tyumen’) for different wave components. The joint use of compressional and shear waves provides a higher-quality interpretation of seismic data in permafrost applications. In the case of a single wave component, shear waves are advantageous over P waves.  相似文献   

The photometric evolution of FU Orionis objects: disc instability and wind–envelope interaction     

C. Clarke  G. Lodato  S. Y. Melnikov  M. A. Ibrahimov 《Monthly notices of the Royal Astronomical Society》2005,361(3):942-954

We present the results of a photometric monitoring campaign of three well-studied FU Orionis systems (FU Orionis, V1057 Cygni and V1515 Cygni) undertaken at Maidanak Observatory between 1981 and 2003. When combined with photometric data in the literature, this data base provides a valuable resource for searching for short time-scale variability – both periodic and aperiodic – as well as for studying the secular evolution of these systems. In the case of V1057 Cyg (which is the system exhibiting the largest changes in brightness since it went into outburst) we compare the photometric data with time-dependent models. We show that prior to the end of the 'plateau' stage in 1996, the evolution of V1057 Cyg in the V –( B − V ) colour–magnitude diagram is well represented by disc instability models in which the outburst is triggered by some agent – such as an orbiting planet – in the inner disc. Following the end of the plateau phase in 1996, the dimming and irregular variations are consistent with occultation of the source by a variable dust screen, which has previously been interpreted in terms of dust condensation events in the observed disc wind. Here we instead suggest that this effect results from the interaction between the wind and an infalling dusty envelope, the existence of this envelope having been previously invoked in order to explain the mid-infrared emission of FU Orionis systems. We discuss how this model may explain some of the photometric and spectroscopic characteristics of FU Orionis systems in general.  相似文献   

Nonthermal Electron Diffusion Modes in Whistler Turbulence in Flare Loops     

Melnikov  V. F.  Filatov  L. V. 《Geomagnetism and Aeronomy》2021,61(8):1189-1196

Geomagnetism and Aeronomy - Nonthermal electron-diffusion modes in whistler turbulence in flare loops are studied for the nonstationary case. It is shown that for the given injection time profile...  相似文献   

First data on composition of the volcanic rocks of the IVS 50th anniversary Fissure Tolbachik eruption (Kamchatka)     

A. O. Volynets  D. V. Melnikov  A. I. Yakushev 《Doklady Earth Sciences》2013,452(1):953-957

First data on major, minor and trace element (XRF. 1CP-MS) concentrations in the volcanic rocks of the IVS 50th anniversary Fissure Tolbachik eruption are reported for the period from 27.11.2012 to 25.01.2013; scheme of lava flows distribution by March 2013 is made. The volcanic rocks of the new eruption are substantially different from the other studied volcanic rocks of Tolbachinsky Dol by their higher alkalis and incompatible elements content. The rocks of the first three days of eruption (Menyailov Vent) have higher silica and alkalis content than all previously reported volcanic rocks of Tolbachinsky Dol. Volcanic rocks of the Naboko Vent, at silica content similar to high-Al basalts of Tolbachinsky Dol, have different concentrations of trace elements and some major elements (K₂O, CaO, TiO₂, P₂O₅). REE and other incompatible element concentrations in the rocks of the Menyailov Vent are higher than in the rocks of the Naboko Vent at the same element ratios. The differences of the volcanic rocks of the two vents of the new eruption may be caused by the fact that the erupted lavas came from the different levels of the same magma chamber.  相似文献   

Spatial brightness distribution of hard X-Ray emission along flare loops     

V. F. Melnikov  Yu. E. Charikov  I. V. Kudryavtsev 《Geomagnetism and Aeronomy》2013,53(7):863-866

The work is devoted to the simulation of recently discovered hard X-ray and gamma radiation sources localized near the top of solar flare loops. The calculations were performed in the context of a model of a flare magnetic loop inhomogeneous with respect to the magnetic field. Two cases of injection were considered: isotropic and anisotropic along the loop axis. The distributions of electrons along the loop are found by solving the nonstationary relativistic kinetic equation in the Fokker-Planck form. Based on the calculated electron distribution functions, the spatial brightness distribution of hard X-ray and gamma radiation has been calculated. Radiation characteristics are compared for different sets of injection parameters.  相似文献   

Active star-forming region in Orion KL, epoch 2012     

L. I. Matveyenko  V. A. Demichev  A. V. Ipatov  A. E. Melnikov  I. F. Surkis 《Astronomy Letters》2012,38(12):764-770

Polarization measurements of the H₂O maser emission from the active region in Orion KL were carried out at epoch 2011?C2012 on the Svetloe-Zelenchukskaya radio interferometer. The bipolar outflow structure and polarized emission parameters have been determined. The emission from the components at v = 7.6 and 7.0 km s^?1 dominates in the line profile; the relative contribution of the former component has increased. The velocity of the bipolar outflow ejector region is almost equal to that of the local standard of rest v _LSR = 7.65 km s^?1, while the velocity of the remote component is v = 7.0 km s^?1. The emission from the bipolar outflow is observed at a distance up to 11 mas from the ejector. Its diameter does not exceed 0.3 mas. The outflow orientation in the plane of the sky is ?37°. The outflow velocity components along the line of sight differ by ??v = 0.3 km s^?1. The polarization levels of the bipolar outflow and the remote component reach m = 62 and 39%, respectively.  相似文献