共查询到20条相似文献，搜索用时 31 毫秒
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V. V. Shcherbakova G. V. Zhidkov V. P. Shcherbakov 《Izvestiya Physics of the Solid Earth》2008,44(10):816-821
A large volume of data on the paleointensity H an obtained by A.S. Bol’shakov and G.M. Solodovnikov is ignored in modern reconstructions because the authors did not indicate whether they used the check-point procedure for the detection of chemical alterations in rocks associated with determination of H an. The paper presents new values of H an determined by the Thellier-Coe method with the use of the checkpoint procedure from samples of the Armenian collection of Cretaceous rocks used in published studies of Bol’shakov and Solodovnikov. The new results are close to the published ones and point to a small value of the geomagnetic field in the Cretaceous, thereby corroborating Bol’shakov-Solodovnikov’s hypothesis on a low paleofield in the Mesozoic. Our study of samples of the collection studied confirms the reliability of Bol’shakov-Solodovnikov’s determinations of H an. 相似文献
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Izvestiya, Physics of the Solid Earth - 相似文献
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Izvestiya, Physics of the Solid Earth - Abstract—In my comment on the paper by A.A. Lyubushin, G.N. Kopylova, and Yu.K. Serafimova, I focus on the problem of legitimacy of seismological data... 相似文献
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O. M. Raspopov K. G. Ivanov E. I. Mogilevskii A. D. Shevnin 《Geomagnetism and Aeronomy》2011,51(1):1-5
Information is given regarding the life, work, scientific research, and organizational activities of Professor Yu.D. Kalinin,
the founder and the first editor-in-chief of the journal “Geomagnetism and Aeronomy.” The paper is devoted to the centenary
of the birth of Yu.D. Kalinin and to the 50th anniversary of the beginning of the publication of the journal. 相似文献
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All existing data (6 years) on gravity wave activity, inferred from the nighttime A3 (oblique incidence on the ionosphere) radio wave absorption measurements in the lower ionosphere on 270 kHz at Prhonice in Central Europe, have been exploited to get information on the effects of QBO phases and the Mt. Pinatubo volcanic eruption on the gravity wave activity in the winter half of the year. There appears to be an enhancement of gravity wave activity in the two winters just after the strong volcanic eruption of Mt. Pinatubo. This enhancement is remarkable for long-period waves (T=2–3 hours). No clear effect of the phase of QBO on the level of gravity wave activity has been found; a possible effect of QBO on the correlations between gravity wave activities in individual period bands is indicated. The results are limited by a relatively short data series; however, no more data will he available. 相似文献
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Zhang Shiqi 《国际泥沙研究》2000,(3)
Mr. Singh and Mr. Ghosh have carefully reviewed and made valuable suggestions and comments. Theauthor would like to express his gratitude to them. The explanations to the comments and some detailsof the model development are as follows.1 MATHEMATICAL MODEL ON SUSPENDED SEDIMENT TRANSPORTATIONThere are three types of models on sediment transportation, i.e. for simulating (1) bedload; (2)suspended sediment; and (3) all sediment including bedload and suspended sediment. In t… 相似文献
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N. D. Diamantides 《Annales Geophysicae》1998,16(5):492-509
The research task described herein aims at the structuring of an analytical tool that traces the time course of geophysical phenomena, regional or global, and compares it to the course of long-term solar conditions, long-term meaning decades or a few centuries. The model is based on the premise that since in a last analysis the preponderance of atmospheric, hydrospheric, and, possibly, some aspects of geospheric phenomena are, or have been, powered by energy issuing from the sun – either now or in the past – the long-term behavior of such phenomena is ultimately connected to long-term changes occurring in the sun itself. Accordingly, the proposed research firstly derives and models a stable surrogate pattern for the long-term solar activity, secondly introduces a transfer-function algorithm for modeling the connection between the surrogate and terrestrial phenomena viewed as partners in the connection, and thirdly probes the connection outcome for episodic or unanticipated effects that may arise due to the fact that in the present context, the connection, should it exist, is very likely nonlinear. Part I of the study presents the theory of the concept, while Part II demonstrates the concepts pertinence to a number of terrestrial phenomena. 相似文献
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V. F. Belyi 《Journal of Volcanology and Seismology》2010,4(3):149-163
A detailed petrographic study of the impactites found in the El’gygytgyn depression suggested a division of those into the
dacite-rhyolite (dominant) and the andesite-basalt (about 1% of the total impactite volume) groups. The protolith for the
dacite-rhyolite group was the Cretaceous ignimbrite rock association of the Okhotsk-Chukchi volcanic belt (OChVB), from which
the depth of their origin is estimated as 1–1.5 km. The impactites of the andesite-basalt group, which are generally older,
formed from protoliths of apparently metamorphic and magmatic complexes in the OChVB basement occurring at depths of 6.5–8.5
km. The hypothesis that the depths of origin for these groups are different is supported by certain features of clinopyroxene
composition. Geochemical relationships are found to exist between deep and shallow impactites, as shown in the distribution
of Ni, Cr, and Co. The succession of development for the shallow impactite generation forms the following series: impact ignimbrite
→ pumice → cinder → massive glass. The glasses have the most homogeneous overall chemical composition, but these too are characterized
by a high inhomogeneity in the composition of the vitric phases, indicating a rapid and discrete impactite generation that
impeded melt homogenization. The glasses are the final product of impactite generation; they show a dramatic drop in fluid
content and the associated reducing components. 相似文献
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It is well known that the results of determining earthquake parameters depend to a large extent on data processing algorithms and velocity models of the seismic wave propagation medium used in solving hypocenter problems. In 1992, V.Yu. Burmin developed a hypocentric algorithm that minimizes the functional of distances between the points corresponding to the theoretical and observed travel times of seismic waves from an earthquake source to recording stations. The determination of the coordinates of earthquake hypocenters in this case is much more stable than for the commonly used minimization of the functional of discrepancies in the seismic wave arrival times at a station. Using this algorithm and the refined velocity model of the medium, V.Yu. Burmin and L.A. Shumlyanskaya reinterpreted the earthquake parameters for the Crimea–Black Sea region. The most important result of this reinterpretation was the conclusion about the occurrence of deep earthquakes with a source depth of more than 60 km in the region. This result contradicts the conventional beliefs about the seismicity of the region and therefore aroused strong criticism from experts directly involved in compiling the existing catalogs of regional earthquakes. These comments and criticisms are presented by V.E. Kulchitsky with coauthors in a work published in this issue of the journal. In the present paper, we analyze the comments in detail and respond. In particular, we show that the previously used methods of seismic data processing made it highly unlikely by default that deep earthquakes would appear in the results. As an example, we refer to the use of travel-time curves for depths down to 35 km. It is clear that deep earthquakes could not have been found with this approach. 相似文献
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V. G. Eselevich V. M. Bogod I. V. Chashey M. V. Eselevich Yu. I. Yermolaev 《Geomagnetism and Aeronomy》2009,49(1):133-135
The solar sources of the magnetic storms of November 8 and 10, 2004, are analyzed. The preliminary results of such an analysis [Yermolaev et al., 2005] are critically compared with the results of the paper [Tsurutani et al., 2008], where solar flares were put in correspondence with these magnetic storms. The method for determining solar sources that cause powerful magnetospheric storms is analyzed. It has been indicated that an optimal approach consists in considering coronal mass ejections (CMEs) as storm sources and accompanying flares as additional information about the location of CME origination. 相似文献
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《Journal of Atmospheric and Solar》1999,61(12):913-923
An updated version of the equivalent circuit model for simulating the ionospheric dynamo process is described. The contributions of the E and F regions to the flux tube integrated conductivities are compared. The results confirm that the ionospheric electric process is controlled by the E region during daytime but by the F region during nighttime. The F region has a larger effect on the dynamo processes during solar maximum than at solar minimum, and during equinox than in solstice. 相似文献
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S. M. Molodenskii 《Izvestiya Physics of the Solid Earth》2017,53(2):173-180
The question of ambiguity in the solution of the inverse problem for determining the Brünt-Väisäla frequency in the Earth’s mantle from the entire set of the up-to-date data on seismicity, free oscillations, and forced nutations of the Earth, as well as the data on the Earth’s total mass and total moment of inertia, is considered. Based on the results of a series of numerical experiments, the band of admissible distributions of the Brünt-Väisäla frequency and mantle density with depth is calculated. This estimate is used for investigating the convective and gravitational stability of the different regions of the mantle against relatively small adiabatic and nonadiabatic perturbations. The generalization of the known Rayleigh criterion of convective stability of homogeneous and a nonself-gravitating incompressible viscous fluid for the case of a compressible self-gravitating fluid is given. A system of the ordinary eight-order differential equations with complex coefficients and homogeneous boundary conditions, whose eigenvalues determine the transition from the stable state to instability, is obtained. Examples of the numerical determination of these eignevalues are presented. For interpreting the data about the band of the admissible distributions of the Brünt-Väisäla frequency with depth, the notion of the effective bulk modulus of the medium at different depths is introduced. This quantity governs the depth changes in temperature in a convecting mantle and allows us to make a conclusion about the role of heat conduction and the radial heterogeneity of the mantle composition without imposing any constraints on the convection mechanism. It is shown that within the present-day observation errors in the frequencies of the Earth’s free oscillations, the simplest reasonable model is that in which the ratio of the effective bulk modulus to its adiabatic value in the lower and middle mantle is 1.043 ± 0.05. The closeness of this value to unity indicates that convection in the lower and middle mantle is fairly close to adiabatic. At the same time, when the analysis only relies on seismic data and on the information about the periods of the free oscillations of the Earth, there is a significant uncertainty in the models of the effective bulk modulus distribution in the upper mantle and crust. This uncertainty precludes us from making purely empirically derived conclusions that reliably and unambiguously describe the role of the effects of heat conduction and radially heterogeneous material composition in the convection in the upper mantle. 相似文献