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Doklady Earth Sciences - The results of spectral analysis of coordinates obtained by continuous data acquisition using a stationary GPS receiver at the Mikhnevo Geophysical Observatory, Institute... 相似文献
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Doklady Earth Sciences - Based on the Chelyabinsk (February 13, 2013) and Lipetsk (June 21, 2018) events, disturbances in the Earth’s geomagnetic field, which were induced by the fall of... 相似文献
84.
Electromagnetic signals generated by the electric polarization during the constrained deformation of rocks 总被引：1，自引：0，他引：1
The results of synchronous observations of the electric field on the shallow crustal layers of the Earth’s crust and the microseismic vibrations are presented. On the basis of the coincidence of the statistics of the electric and microseismic pulses of the relaxation type, and, also, the fact that the indicated pulses accompany each other, the conclusion is reached about the unique source of both pulses. The constrained rotation of the structural block during its relaxation is considered as such a source. A mechanism is proposed for the generation of electromagnetic signals, connected with the separation of electric charges as a result of the rapid change in the stress-strain state of the rocks of a complex hierarchic-block structure. A model developed by the authors, for the generation of electromagnetic signals during the relaxation processes in the Earth’s crust of a heterogeneous structure, is presented. 相似文献
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Microseismic noise was studied in the frequency range 0.5–30 Hz in the conditions prevailing in the town of Vorkuta. A seismic
noise model was developed consisting of power spectral densities of ground motion velocity separately for daytime and nighttime
in different frequency ranges. The absolute noise level for frequencies of 1–5 Hz in Vorkuta varies between −140 and −150
dB in daytime and from −152 to −158 dB in nighttime, with the ranges for the 8-15 Hz noise being −140 to −155 dB in daytime
and −155 to −165 dB in nighttime. Well-pronounced daily variations in noise amplitude were observed in the frequency ranges
1.5–3 Hz and 14–17 Hz. The noise amplitude varies by 7 dB over 24 hours, with the amplitude of horizontal component variation
being 5 dB above that of the vertical component. The power spectral densities of ground motion velocity in the microseismic
noise involve several spectral peaks, whose central frequencies did not vary by more than 0.15 Hz during the entire period
of instrumental observation. The seismic background in the town of Vorkuta contains seismic events due to distant earthquakes
and local industrial explosions. 相似文献
86.
The Earth’s free oscillations are recorded for the first time in variations of the geomagnetic field measured at the Earth’s surface. The Earth’s free oscillations in the frequency range from 0.3 to 4 mHz manifest in the spectra of geomagnetic variations in the form of clearly expressed quasi-harmonic peaks. It is shown that the spectral amplitudes of the main modes of the Earth’s free oscillations are not constant and change with a periodicity corresponding to a lunar (sideral) month. The data obtained indicate the influence of oscillations in the internal geospheres on variations in the terrestrial magnetic field. The results provide new opportunities to study the Earth’s free oscillations and to specify their multiplet components. In addition, they also have certain implications for further research into the internal structure of the Earth and geodynamic processes in internal geospheres, on the basis of magnetometric data. 相似文献
87.
Yu. A. Litvin A. V. Spivak D. A. Simonova L. S. Dubrovinsky 《Doklady Earth Sciences》2017,473(2):444-448
Experimental studies of phase relations in the oxide–silicate system MgO–FeO–SiO2 at 24 GPa show that the peritectic reaction of bridgmanite controls the formation of stishovite as a primary in situ mineral of the lower mantle and as an effect of the stishovite paradox. The stishovite paradox is registered in the diamond-forming system MgO–FeO–SiO2–(Mg–Fe–Ca–Na carbonate)–carbon in experiments at 26 GPa as well. The physicochemical mechanisms of the ultrabasic–basic evolution of deep magmas and diamondforming media, as well as their role in the origin of the lower mantle minerals and genesis of ultradeep diamonds, are studied. 相似文献
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Spivak A. A. Riabova S. A. Rybnov Yu. S. Kharlamov V. A. 《Doklady Earth Sciences》2021,500(2):852-856
Doklady Earth Sciences - The analysis of the instrumentally observed variations in the error of determining coordinates by the GPS navigation satellite system, performed at the Mikhnevo Geophysical... 相似文献
90.
Based on complex analysis of the results of instrumental observations during strong atmospheric disturbances, it is shown that hurricanes and squalls are accompanied not only by high wind velocities, but also by high-amplitude microbaric variations, variations in amplitudes of the microseismic background, and the vertical component of the electric field. It is established that 1–4 hours before the onset, squalls and hurricanes are characterized by increased amplitudes of microbaric variations in the range of periods of 2–6 min, as well as by low-frequency variations in the electric field and variations in the microseismic background, which together with the meteorological parameters can be considered as a complex prognostic criterion of an impending hurricane (squall). 相似文献