Variations in the Parameters of Background Seismic Noise during the Preparation Stages of Strong Earthquakes in the Kamchatka Region

Multifractal and entropy statistics of seismic noise in Kamchatka in connection with the strongest earthquakes

“…Как было показано ранее в работах [Lyubushin, 2018;Lyubushin, 2021c;Lyubushin, 2021b;Lyubushin, 2021a;Lyubushin, 2022], увеличение опасности сильных землетрясений в различных сейсмоактивных регионах сопровождается уменьшением параметров γ и Δα и увеличением энтропии En сейсмического шума. Из предшествующих работ авторов [Kasimova, Kopylova, Lyubushin, 2018;Kopylova et al, 2022]…”

“…Данная статья представляет дальнейшее развитие методов оценки свойств сейсмического шума на Камчатке и их изменчивости в связи с сильными землетрясениями. Результаты предыдущих исследований по этой теме представлены в работах [Kasimova, Kopylova, Lyubushin, 2018;Lyubushin, Kopylova, Serafimova, 2021;Kopylova et al, 2022].…”

Variability in the Statistical Properties of Continuous Seismic Records on a Network of Stations and Strong Earthquakes: A Case Study from the Kamchatka Peninsula, 2011–2021

“…In records from continental stations, mainly diurnal maxima are distinguished. Whereas diurnal and semidiurnal maxima, as well as maxima on the periods of powerful lunar waves M2 (period 12.42 h) и О1 (period 25.82 h), are clearly distinguished in the spectra of records from coastal stations [35,36]. Such features of seismic noise records showed a high degree of signal noisiness at coastal stations due to sea tidal waves.…”

“…To analyze spatiotemporal variations of seismic noise, time series of the daily values of four statistical parameters were used: generalized Hurst exponent α*, singularity spectrum support width ∆α, wavelet-based spectral exponent β, and minimum normalized entropy of squared orthogonal wavelet coefficients En calculated for all stations during the 2011-2021 observation period [35,36,39]. The statistical parameters of seismic noise were estimated according to daily data of 1-min signal registration on BHZ channels for all stations (Figure 1, Table 1).…”

“…. By construction, 0 ≤ En ≤ 1. www.videleaf.com When estimating the wavelet spectral exponent β, the orthogonal wavelet decomposition of the signal fragments in the current daily time window [5] is used, which was previously used in [43] to analyze the noise component of signals from a network of 1203 GPS stations in Japan before the Tohoku mega earthquake on March 11, 2011, and in [36,39] when processing noise data from the Kamchatka Peninsula.…”