3:30 PM - 4:30 PM
[S11-P-03] Variations of statistical parameters of the background seismic noise before strong earthquakes in Kamchatka
The network of broadband seismic stations of Geophysical service RAS works on the territory of Kamchatka peninsula in the Far East of Russia. We used a method for seismic noise analysis which is described in [1-2]. We used continuous records on Z-channels at 21 stations for creation of background seismic noise time series in 2011-2016 with sampling 1 minute. Average daily parameters of multi-fractal spectra of singularity have been calculated at each station using 1-minute records. Maps and graphs of their spatial distribution and temporal changes were constructed at time scales from days to six months. Also, the time series of daily median values of the statistical parameters of the noise were calculated on all stations.
Three strong earthquakes with magnitudes M=6.9–8.3 occurred near the Kamchatka peninsula during the observations. The synchronous variations of the background noise parameters and increase in the coherent behavior of the median values of statistical parameters was shown before two strong earthquakes 2013 (February 28, MW=6.9; May 24, MW=8.3) within 3–9 months and before the earthquake of January 30, 2016, MW=7.2 within 3–6 months.
Peculiarities in changes of statistical parameters at stages of preparation of strong earthquakes indicate an attenuation in high-amplitude outliers and the loss of multi-fractality in time series of noise. The changes in the various statistical parameters before strong earthquakes on Kamchatka corresponds to their behavior during the preparation of the strongest earthquakes near Japan in 2003, M=8 and in 2011, M=9.
1. Lyubushin, A. Prognostic properties of low-frequency seismic noise. Natural Science, 2012, 4(8A), 659-666. http://dx.doi.org/10.4236/ns.2012.428087
2. Lyubushin, A. A., Dynamic estimate of seismic danger based on multifractal properties of low-frequency seismic noise. Natural Hazards, 2014, 70 (1), 471-483.
http://dx.doi.org/10.1007/s11069-013-0823-7
Three strong earthquakes with magnitudes M=6.9–8.3 occurred near the Kamchatka peninsula during the observations. The synchronous variations of the background noise parameters and increase in the coherent behavior of the median values of statistical parameters was shown before two strong earthquakes 2013 (February 28, MW=6.9; May 24, MW=8.3) within 3–9 months and before the earthquake of January 30, 2016, MW=7.2 within 3–6 months.
Peculiarities in changes of statistical parameters at stages of preparation of strong earthquakes indicate an attenuation in high-amplitude outliers and the loss of multi-fractality in time series of noise. The changes in the various statistical parameters before strong earthquakes on Kamchatka corresponds to their behavior during the preparation of the strongest earthquakes near Japan in 2003, M=8 and in 2011, M=9.
1. Lyubushin, A. Prognostic properties of low-frequency seismic noise. Natural Science, 2012, 4(8A), 659-666. http://dx.doi.org/10.4236/ns.2012.428087
2. Lyubushin, A. A., Dynamic estimate of seismic danger based on multifractal properties of low-frequency seismic noise. Natural Hazards, 2014, 70 (1), 471-483.
http://dx.doi.org/10.1007/s11069-013-0823-7