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The influence of the finite ionospheric conductivity on the structure of dispersive, nonradiative field line resonances (FLRs) is investigated for the first four odd harmonics. The results are based on a linear, magnetically incompressible, reduced, two-fluid MHD model. The model includes effects of finite electron inertia (at low altitude) and finite electron pressure (at high altitude). The ionosphere is treated as a high-integrated conducting substrate. The results show that even very low ionospheric conductivity (P = 2 mho) is not sufficient to prevent the formation of a large-amplitude, small-scale, nonradiative FLR for the third and higher harmonics when the background transverse plasma inhomogeneity is strong enough. At the same time, the fundamental FLR is strongly affected by a state of low conductivity, and when P = 2 mho, this resonance forms only small-amplitude, relatively broad electromagnetic disturbance. The difference in conductivities of northern and southern ionospheres does not produce significant asymmetry in the distribution of electric and magnetic fields along the resonant field line. The transverse gradient of the background Alfven speed plays an important role in structure of the FLR when the ionospheric conductivity is finite. In cases where the transverse inhomogeneity of the plasma is not strong enough, the low ionospheric conductivity can prevent even higher-harmonic FLRs from contracting to small scales where dispersive effects are important. The application of these results to the formation and temporal evolution of small-scale, active auroral arc forms is discussed. 相似文献
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The Neftegorsk, Sakhalin Island, earthquake of 27 May 1995 总被引：1，自引：0，他引：1
A. I. Ivashchenko Ch.U. Kim L. S. Oscorkin L. N. Poplavskaya A. A. Poplavsky R. N. Burymskaya T. G. Mikhailova N. F. Vasilenko M. I. Streltsov 《Island Arc》1997,6(3):288-302
Abstract Past seismic catastrophes were unknown in Sakhalin Island before 1995 except those suggested from findings of paleoseismodislocations. The first time that dwellers have experienced such a catastrophe in the Sakhalin Island history was on 27 May 1995. The devastating Neftegorsk earthquake occurred in Northern Sakhalin (?= 52.8° north; δ= 143.2° east; H = 18 km; Ms= 7.2), killed almost 2000 people in the small city of Neftegorsk, caused damage and destruction of buildings, bridges, railways and roads, breakage of oil and gas pipelines, electric and communication lines, and was accompanied by large-scale surface phenomena within a source area. It was felt all over the Sakhalin Island, as well as over the closest part of the Eurasian continent. Surface fracturing was the most impressive effect of the Neftegorsk earthquake. The 37-km long, right-lateral strike-slip fault, with a strike of north 15° east and a horizontal displacement up to a maximum of 8 m, has been observed from Taxon Mountain at the south to the junction of the Cadylanye and Keniga Rivers at the north. According to the results of a detailed geological survey and study of the aftershocks, the total extent of the source area was - 80 km. Various secondary phenomena have been observed at the Earth's surface, such as landslides, falls, soil liquefaction, mud volcanoes etc. The earthquake was followed by hundreds of aftershocks within the following 1-2 months. Spatially, the earthquake fault coincides with the pre-existing Upper Piltun fault, known earlier from geological studies. Recent high activity of the latter fault has been recognized only after the Neftegorsk event because of findings of traces of significant past dislocations within the fault zone. From a tectonic viewpoint it can be suggested that the Upper Piltun fault is a Riedel-type shear fracture located between two main regional faults: the Gyrgylanye-Dagy fault at the west and the Piltun-Ekhaby fault at the east. Therefore, its present activity, expressed by the destructive Neftegorsk earthquake, seems to be explained by a long strain accumulation within a broad zone of regional right-lateral shear faulting. 相似文献
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Uspensky A. B. Asmus V. V. Kozlov A. A. Kramchaninova E. Streltsov A. M. Chernyavsky G. Ya. Cherny I. V. 《Izvestiya Atmospheric and Oceanic Physics》2017,53(9):1192-1204
Izvestiya, Atmospheric and Oceanic Physics - The microwave MTVZA-GY imager/sounder is one of the key instruments onboard the Meteor-M N2 satellite (launched in July, 2014). The MTVZA-GY data... 相似文献
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M. I. Streltsov 《Island Arc》1997,6(3):234-243
Abstract It is well known that knowledge about convergent boundary geometry is crucial for global geodynamical reconstructions. At the same time, views related to the subject are controversial and speculative. For instance, island arcs, which are considered to be the most important convergent boundary structural elements, are thought to be either the parts of the small circles on the Earth's surface, or adjacent to each other as straight-line segments. Accordingly, one view says that island arcs are rectilinear rather than arched, and there are no reasons to consider their arched shape to be a rule. Is the island arc curvature invariant in time and space? General considerations, palaeomagnetic data and structural features such as strike-slip displacements of the opposite sign along the longitudinal faults on the island arc flanks, prompt the author to have a similar view to others, that is, that island arc curvature varies with time. It is worthy to note, nevertheless, that this statement could hardly be referred to as generally adopted, and it is not necessarily true. One can try to answer the second part of the question by means of mathematical statistics. Points of an island arc characterizing the geometry, such as volcanic centres or deep-trench axial line points, were led to the stereographical projection centre, where distortions are minimal. By the least squares method these points have been approximated with straight lines, circumferences and lines with variable curvature. Then by means of variance analysis the competing hypotheses have been compared. The results of the present study show that the curvature of the island arcs in the north-western Pacific varies with location. It is possible to search for relationships between island arc curvature as a measure of its bending, various physical parameters of island arc lithosphere and such recent island arc processes as volcanism, seismicity etc. Progress in this direction has already been made; namely a direct relationship between trench depth and island arc curvature has been established. 相似文献
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Yu. A. Teterin V. M. Kulakov A. S. Baev N. B. Nevzorov I. V. Melnikov V. A. Streltsov L. G. Mashirov D. N. Suglobov A. G. Zelenkov 《Physics and Chemistry of Minerals》1981,7(4):151-158
Synthetic and natural uranium oxides UO x (2≦×≦3) have been studied with X-ray photoelectron spectroscopy (XPS) to determine the phase composition and content of uranium ions in uraninites with a varying degree of oxidation. A strong hybridization of U6p and O2s orbitals has been found which permits a quantitative assessment of the U-O bond lengths. The values of such bonds in some substances have been found to be smaller than those in synthetic U(VI) oxide. The oxides U2O5 and U3O8 contain two types of uranium ions with a varying degree of oxidation. 相似文献
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