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

Abstract

A study of spatiotemporal variability and synchronization effects in continuous seismic records (seismic noise) on a network of 21 broadband seismic stations on the Kamchatka Peninsula was carried out in connection with the occurrence of strong earthquakes, M = 7.2–8.3. Data of 1-min registrations of the vertical movements velocity Earth’s surface were used for constructing time series of daily values of the generalized Hurst exponent α*, singularity spectrum support width ∆α, wavelet-based spectral exponent β, and minimum normalized entropy of squared orthogonal wavelet coefficients En for all stations during the observation period 2011–2021. Averaged maps and time-frequency diagrams of the spectral measure of four noise parameters’ coherent behavior were constructed using data from the entire network of stations and by groups of stations taking into account network configuration, volcanic activity and coastal sea waves. Based on the distribution maps of noise parameters, it was found that strong earthquakes arose near extensive areas of the minimum values of α*, ∆α, β, and the En maximum values advance manifestation during several years. The time-frequency diagrams revealed increased amplitudes of the spectral measure of the coherent behavior of the 4-dimensional time series (synchronization effects) before three earthquakes with Mw = 7.5–8.3 over months to about one year according to observations from the entire network of stations, as well as according to data obtained at groups of continental and non-volcanic stations. A less-pronounced manifestation of coherence effects diagrams plotted from data obtained at coastal and volcanic groups of stations and is apparently associated with the noisiness in seismic records caused by coastal waves and signals of modern volcanic activity. The considered synchronization effects correspond to the author’s conceptual model of seismic noise behavior in preparation of strong earthquakes and data from other regions and can also be useful for medium-term estimates of the place and time of seismic events with Mw ≥ 7.5 in the Kamchatka.

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

“…Энтропия сейсмического шума (1) неоднократно применялась в работах [Lyubushin, 2018;Lyubushin, 2020b;Lyubushin, 2020a;Lyubushin, 2021c;Lyubushin, 2021b;Lyubushin, 2021a;Lyubushin, 2022] для анализа изменчивости сейсмического шума в различных регионах Земли и на глобальном уровне в качестве самостоятельного инструмента. По своей конструкции энтропия (1) является также многомасштабной, как и энтропия, предложенная в работах [Costa et al, 2003;Costa, Goldberger, Peng, 2005] для исследования свойств случайных сигналов.…”

“…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]…”

“…Источником энергии сейсмического фона Земли являются в основном воздействия атмосферных циклонов на земную поверхность и океанских волн на шельф и побережье [Ardhuin et al, 2011;Aster, McNamara, Bromirski, 2008;Friedrich, Kruger, Klinge, 1998;Kobayashi, Nishida, 1998;Koper, Seats, Benz, 2010;Rhie, Romanowicz, 2004;Tanimoto, 2005]. Естественно предположить, что, поскольку земная кора и верхняя мантия являются средой распространения сейсмических волн, внутренние процессы отражаются в изменении статистических свойств сейсмического шума, и изучение этих свойств позволяет рассматривать особенности строения земной коры [Berger, Davis, Ekstrom, 2004;Fukao, Nishida, Kobayashi, 2010;Nishida, Montagner, Kawakatsu, 2009], а также изменения свойств шума, предшествующие сильным землетрясениям [Lyubushin, 2018;Lyubushin, 2021c;Lyubushin, 2021b;Lyubushin, 2022;Lyubushin, 2023].…”

“…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].…”

Special Issue on Comprehensive Research in Earthquake Forecasting and Seismic Hazard Assessment

“…The second group includes articles confirming one or another model of seismicity behaviour in anticipation of a strong earthquake [3][4][5]. Finally, the third and most numerous group of articles consists of those analysing the results of long-term observations of the behaviour of various geophysical fields (seismic noise [6], seismicity [7][8][9], magnetotelluric field [10,11], deformation field [12], infrared radiation [13], vertical electric field in the atmosphere [14]) before strong earthquakes. We are confident that each of these articles will find an interested reader, and the whole collection will deserve the attention of representatives of the scientific community dealing with the problem of earthquake forecasting and the search for their precursors.…”