Variations in ambient seismic noise generated by the Kyngarga river (Tunka Valley) in the calm state and during significantly rising water levels were analyzed, based on the Arshan short-period seismic station data, observations of water level fluctuations at the Kyngarga Rv. hydrological station, and the amount of rainfall measured with precipitation gauge at Peak Lyubvi mountain (Mt). The methods used in the work include the correlation, spectral, spectral-temporal and polarization analyses. Ambient noise vibrations recorded at the Arshan seismic station show instable over time and show significant seasonal variations. During warm periods, the ice cover melting increases the water level in the Kyngarga River, thus causing amplification of seismic vibrations in the frequency range from 2 to 20 Hz. Occurrence of heavy rainfalls and subsequent significant rise in the Kyngarga river water levels (floods) lead to changes in the amplitude-to-frequency response characteristics of ambient seismic noise. This translates into amplification of seismic vibrations in the frequency range from 4 to 20 Hz, with maximum seismic radiation (radiative transfer of seismic waves) in the 6–10 Hz frequency range. For different floods, the amplification varies significantly and depends on the magnitude of the water level rise. Variation of amplitude-frequency characteristics of the ambient seismic noise in summer relative to winter, as well as during floods, is driven by increased water flow turbulence with affiliated increase in water flow velocity and discharge, and sediment dynamics. Diagrams showing particle motion in the medium in a calm state and during floods do not show any dominant orientation of oscillations, which is associated with the length of the source of vibrations whose extent (in this case) is equal to the entire river channel.

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