Deep Electrical Conductivity in the Vicinity of the Orsha Depression: 2D REBOCC Inversion of Synthetic and Observed Magnetotelluric Data     

Ivanov  P. V.  Varentsov  Iv. M.  Kolodyazhnyi  S. Yu.  Lozovsky  I. N.  Pushkarev  P. Yu.  Rodina  T. A. 《Izvestiya Physics of the Solid Earth》2022,58(5):626-641

Izvestiya, Physics of the Solid Earth - Abstract—The geoelectric structure of the junction region between three largest segments of the East European Craton (EEC)–Volga–Uralia,...  相似文献   

Mesoscale Atmospheric Modeling of Extreme Velocities over the Sea of Okhotsk and Sakhalin     

A. V. Kislov  G. S. Rivin  V. S. Platonov  M. I. Varentsov  I. A. Rozinkina  M. A. Nikitin  M. M. Chumakov 《Izvestiya Atmospheric and Oceanic Physics》2018,54(4):322-326

A detailed modeling of meteorological parameters over the last 30 years (1985–2014) has been performed for the Sea of Okhotsk and Sakhalin regions in the frame of the COSMO-CLM regional mesometeorological nonhydrostatic atmospheric model. The downscaling technology is suggested and achieved with three consequent “nesting domains” (with 13.2-, 6.6-, and 2.2-km grid scales). The COSMO-CLM model reproduces (especially successfully on the 2.2-km grid scale) the extremes of wind velocity observed by meteorological stations well. Synoptic situations accompanied by extreme wind speeds are reproduced in detail.  相似文献   

Modern trends in the solution of forward and inverse 3D electromagnetic induction problems     

Iv. M. Varentsov 《Surveys in Geophysics》1983,6(1-2):55-78

The main results obtained during the last 5–8 yr in the solution of forward and inverse problems of 3D induction studies are summarized. The up-to-date status of 3D modelling is presented and prospective improvements in the formulation and numerical solution of forward problems are discussed. Approximate techniques and practical aspects of 3D modelling are specially considered. The general scheme of 3D interpretation of electromagnetic geophysical observations is outlined and realistic formalized approaches to solving 3D inverse problems, namely direct inversion and formalized model fitting, are studied.  相似文献   

On the study of mechanisms of iron-manganese ore formation in recent basins: the experimental data on nickel and cobalt     

I. M. Varentsov  N. V. Pronina 《Mineralium Deposita》1973,8(2):161-178

The consideration of modes of occurrences, structures, composition and geochemical features of iron-manganese nodules and crusts, which develope on the bottom of recent basins, allows the conclusion to be drawn that they are formed as a result of the interaction of component-bearing solutions (commonly bottom waters) with active surfaces. The results of experiments on the study of sorption by natural iron-manganese hydroxides of Ni and Co from seawater in the presence of complex-forming compounds are reported. Highly selective sorption of Ni and Co was observed. In the runs with biogenic forms of these metals, after 20 days of interaction, as much as 77,8 percent Ni was removed from sea water and complete extraction of Co took place. The range of concentration of these metals in solution was 10 to 100 ppb. The character of the isotherms of the Ni and Co sorption from seawater in the presence of complex-forming agents (citric acid) gives evidence that even with the sorption of high amounts of the metals (10 to 40 weight percent) there is no tendency of reaching the limits of sorption capacity. The experiments on desorption showed that the initial stages of the process are of ion-exchange character, mainly for Ni, to a lesser extent for Co. In the later stages, the formation of nonexchangeable, firmly fixed forms of Co and Ni takes place. These forms are mainly complex, spinel oxides of Ni and Co, according to x-ray diffraction patterns: Co₂NiO₄ and probably with minor amounts of Co Ni O₂, and traces of CoO·OH. Chemosorption plays the leading role with an autocatalytic oxidation process of accumulation of these metals. The newly formed phases act in the future cycles of interaction as active sorbents.

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Zusammenfassung Die Betrachtung der Vorkommen, Gefüge, Zusammensetzung und geochemischen Eigenschaften der Eisen-Mangan-Knollen und -Krusten, die sich am Boden rezenter Becken bildeten, erlaubt Schlußfolgerungen auf ihre Entstehung. Diese Entstehung ist als Ergebnis der Wechselwirkung zwischen Lösungen mit verschiedenen Komponenten (im allgemeinen Bodenwässern) und aktiven Oberflächen aufzufassen. Die experimentellen Ergebnisse bei der Untersuchung der Sorption von Ni and Co durch natürliche Eisen-Mangan-Hydroxide aus dem Meerwasser in Gegenwart komplexer Verbindungen werden mitgeteilt. Es wurde eine weitgehend selektive Aufnahme von Ni und Co festgestellt. In Versuchsserien mit organischen Verbindungen dieser Metalle waren nach einer Reaktionsdauer von 20 Tagen bis 77,8% des Ni und das gesamte Co dem Meerwasser entzogen. Der Gehalt dieser Metalle in Lösung betrug 10–100 ppb. Der Charakter der Isothermen der Ni- und Co-Sorption aus Meerwasser in Gegenwart komplexbildender Reagentien (Zitronensäure) zeigt, daß selbst bei hohen Gehalten an gebundenen Metallen (10–40 Gewichtsprozent) noch keine Tendenz zur Begrenzung der Sorptionsfähigkeit erkennbar ist. Die Experimente über die Desorption zeigten, daß die primären Stadien, vor allem für Ni, etwas weniger für Co, durch Ionenaustausch gekennzeichnet sind. In späteren Stadien bilden sich nicht austauschbare, feste Verbindungen von Ni and Co. Diese Verbindungen sind überwiegend komplexe Spinelle von Ni and Co, aufgrund Röntgendiffraktometeraufnahmen Co₂NiO₄, wahrscheinlich mit geringen Gehalten an CoNiO₂ und Spuren von CoO·OH. Bei der Anreicherung dieser Metalle spielt die chemische Sorption mit einer autokatalytischen Oxidation die Hauptrolle. Die neu gebildeten Phasen reagieren bei den späteren Prozessen des Stoffaustausches als sorptionsfördernd.

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The paper was delivered at the meeting of Commission on Manganese, International Association on Genesis of Ore Deposits (IAGOD) during XXIV Session of International Geological Congress, Montreal, Canada, August 25, 1972.  相似文献   

Reflection of Large Tectonic Structures of the Eastern Part of the Arctic Ocean in the Lithospheric Magnetic Field     

Abramova  L. Yu.  Abramova  L. M.  Varentsov  I. M.  Filippov  S. V. 《Geomagnetism and Aeronomy》2020,60(5):636-643

Geomagnetism and Aeronomy - The article considers maps of the field of lithospheric magnetic anomalies—images of the deep structures of the Arctic Ocean—constructed from observations by...  相似文献   

Modeling an Urban Heat Island during Extreme Frost in Moscow in January 2017     

Yushkov  V. P.  Kurbatova  M. M.  Varentsov  M. I.  Lezina  E. A.  Kurbatov  G. A.  Miller  E. A.  Repina  I. A.  Artamonov  A. Yu.  Kallistratova  M. A. 《Izvestiya Atmospheric and Oceanic Physics》2019,55(5):389-406

Izvestiya, Atmospheric and Oceanic Physics - Using the example of an analysis of an extreme lowering of temperature in Moscow in January 2017, the horizontal and vertical extent of the urban heat...  相似文献   

Interpretation of local two-dimensional electromagnetic anomalies by formalized trial procedure     

M. S. Zhdanov  Iv. M. Varentsov 《Geophysical Journal International》1983,75(3):623-638

Summary. An iterative algorithm is presented to be used in the search for the shape of a 2-D local deep geoelectric inhomogeneity lying in a layered medium; an anomaly having been identified in the usual way by observing an alternating time-harmonic electromagnetic field along the surface of the Earth. The normal section parameters (conductivities and thicknesses) and the excess electrical conductivity (inside inhomogeneity) are assumed to be known. The shape of the inhomogeneity is determined by means of a misfit functional minimization technique. A gradient minimization algorithm is constructed and Tikhonov's regularization scheme is applied to achieve stability of the solution. The effectiveness of such an approach is demonstrated by model calculations and by the interpretation of the Carpathian geomagnetic anomaly. Finally, a brief discussion of the problems of the practical application of this formalized trial procedure is presented. Because of the lack of reliable estimates of the excess conductivity, it is proposed to consider a family of models selected for the set of probable values of model parameters. This family can be treated as a generalized solution of the interpretation problem.  相似文献   

On the model of Mn,Fe, Ni,Co ore formation in recent basins: Experiments with the synthesis of Me-hydroxide phases on Mn3O4     

I. M. Varentsov  N. V. Bakova  Yu. P. Dikov  T. S. Gendler  R. Giovanoli 《Mineralium Deposita》1979,14(3):281-296

Experiments on the sorption of dissolved Ni, Co, Mn, Fe from seawater by Mn₃O₄ reveal a sequence of reactions taking place: Ion exchange, hydrolysis, then autocatalytic oxidation and layer formation on the interface. The composition of the new compounds depends on the kinetics of i) sorption, and ii) interface oxidation. The highest oxidized Me ions accumulate at low sorption rates, i. e. when sorption does not inhibit interface oxidation: 60% Mn⁴⁺, 30% Ni³⁺ & 30% Co³⁺ are a representative example for that layer type. Iron is present in this layer as amorphous FeOOH·xH₂O according to Mössbauer spectra. Specific for the Me sorption by Mn₃O₄ is the interaction of Ni & Co with Mn²⁺ and Mn³⁺ of the sorbent lattice. Mn is found in the solute phase equivalent to 16, 14% of the adsorbed Co or 17, 96% of the adsorbed Ni. These results confirm the earlier presented model on the transition metal accumulation in recent basins as taking place in distinct stages with interface autocatalysis for the Me oxidation playing the main role.  相似文献   

Electromagnetic soundings of the sedimentary cover and consolidated crust in the transition zone from the Moscow syneclise to the Voronezh anteclise: Problems and prospects     

E. D. Aleksanova  Iv. M. Varentsov  M. I. Vereshchagina  V. A. Kulikov  P. Yu. Pushkarev  E. Yu. Sokolova  N. L. Shustov  V. K. Khmelevskoi  A. G. Yakovlev 《Izvestiya Physics of the Solid Earth》2010,46(8):707-716

The methods and results of electromagnetic soundings (EMS) performed in the transition zone from the Moscow syneclise to the Voronezh anteclise in the vicinity of the MSU geophysical base are considered. This base is located in the village of Aleksandrovka in the Yukhnov district of Kaluga area. The composite EMS curves characterizing rock complexes composing the sedimentary cover are constructed, and changes in these complexes within the specified transition zone are traced. The standard curves of magnetotelluric (MT) and magnetovariational (MV) soundings are constructed from the results of long-term measurements at the ALX observation point located at the Moscow State University’s (MSU) geophysical base. The maps of thickness and total longitudinal conductance of the sedimentary cover are constructed from the results of interpretation of MT data obtained in the region. A conductor in the consolidated Earth’s crust is identified within the Voronezh anteclise. Prospects for further investigations of the region are associated with the tracing of the crustal conductor within the Voronezh anteclise, as well as with the organization of an observatory at the MSU’s geophysical base in order to perform long-term measurements of the electromagnetic (EM) and other geophysical fields.  相似文献   

Geoelectric section of the Central Tien Shan: Analysis of magnetotelluric and magnetovariational responses along the Naryn geotraverse     

M. N. Berdichevsky  E. Yu. Sokolova  Iv. M. Varentsov  A. K. Rybin  N. V. Baglaenko  V. Yu. Batalev  N. S. Golubtsova  V. E. Matyukov  P. Yu. Pushkarev 《Izvestiya Physics of the Solid Earth》2010,46(8):679-697

During the past two decades, at the Research station (Bishkek) more than a hundred magnetotelluric and magnetovariational soundings were carried out on the Naryn geotraverse that intersects the Tien Shan region from Lake Balkhash to the Tarim Basin along the 76° E meridian. Integration and complex interpretation of the data of these soundings with improved resolution and reliability of the geoelectric model of the Central Tien Shan section became an urgent challenge. Our paper presents a complex of methods for processing and invariant analysis of the electromagnetic data developed for the solution of this problem. Its application allowed us to validate the choice of the 2D interpretation model for the Naryn Line and to form the adequate ensemble of the data to be inverted. The developed approaches will also be useful in similar studies in the other mountain regions.  相似文献