Multi-spectral detection of statistically significant components in pre-seismic electromagnetic emissions related with Athens 1999, M = 5.9 earthquake

摘要: Abstract A multi-spectral analysis of the kHz electromagnetic time series associated with Athens' earthquake (M = 5.9, 7 September 1999) is presented here, that results to reliable discrimination fracto-electromagnetic emissions from natural geo-electromagnetic field background. Five spectral methods are utilized in order resolve statistically significant variability modes studied dynamical system out a red noise background (the revised Multi-Taper Method, Singular Spectrum Analysis, and Wavelet Analysis among them). The performed reveals existence three distinct epochs for period before earthquake, “quiet”, “transitional” an “active” epoch. Towards end active epoch, during sub-period which approximately starting two days passes into high activity state, where signal become powerful almost all time-scales. temporal behavior each one these further searched through mathematical reconstruction domain those features were found be significant. transition quiet state proved detectable first long time-scales afterwards short scales. Finally, Hurst exponent revealed persistent characteristics embedded strong EM bursts observed