Dynamics of geophysical medium from power spectral density of microseisms before and after earthquakes: case study of Bureya massif, Amur region

Dynamics of geophysical medium from power spectral density of microseisms before and after earthquakes: case study of Bureya massif, Amur region

The time–frequency parameters of weak earthquakes and microseisms are studied. The qualitative and quantitative relationships of the power spectral density of seismic waves are established; these relationships vary in terms of frequency spectrum for the areas of the northeastern framing of the Tan L...

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Bibliographic Details
Published in:Russian journal of Pacific geology Vol. 11; no. 5; pp. 331 - 338
Main Authors: Trofimenko, S. V., Ryabinkin, K. S., Pupatenko, V. V., Kolotova, L. G., Haritonov, M. E.
Format: Journal Article
Language:English
Published: Moscow Pleiades Publishing 01-09-2017
Springer Nature B.V
Subjects:
Case studies
Density
Dynamics
Earth
Earth and Environmental Science
Earth Sciences
Earthquakes
Fault zones
Frequencies
Frequency analysis
Frequency spectra
Geological structures
Geology
Geophysics
Hydroelectric power
Lakes
Microseisms
P-waves
Power plants
Seismic activity
Seismic waves
Spectrum analysis
Amur Russia
Russia
seismic background noise
Amur region
high-quality seismic observations
Bureya massif
weak earthquakes
spectral–temporal analysis
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Summary:The time–frequency parameters of weak earthquakes and microseisms are studied. The qualitative and quantitative relationships of the power spectral density of seismic waves are established; these relationships vary in terms of frequency spectrum for the areas of the northeastern framing of the Tan Lu fault system and Bureya massif. The reason for these differences could be the influence of the crustal geological structure near the observations points. Resulting from the time–frequency analysis of weak earthquakes, two sites located in the Tan Lu fault zone show an increase in the power spectrum at frequencies of 1 to 5 Hz and the resonant excitation of the medium at high frequencies (12.5–35 Hz) for the area of the Bureya hydroelectric power station during the travelling of seismic waves from weak earthquakes. A longer attenuation of the power spectral density of seismic waves at high frequencies is noted, and this may occur due to resonant excitation of the medium and the influence of the dam on the geological medium. On the contrary, this effect was not observed at the second site located near Lake Udyl. It is shown that the increase in power can be attributed to the interaction between seismic waves and spatial inhomogeneities in the Earth’s crust.
ISSN:1819-7140
1819-7159
DOI:10.1134/S1819714017050062