Journal Article

Prognostic Properties of Instantaneous Amplitudes Maxima of Earth Surface Tremor

Rodionov, Eugeny, Lyubushin, Alexey

2024

Overview

A method is proposed for analyzing the tremor of the earth’s surface, measured by GPS, in order to highlight prognostic effects. The method is applied to the analysis of daily time series of vertical displacements in Japan. The network of 1047 stations is divided into 15 clusters. The Huang Empirical Mode Decomposition (EMD) is applied to the time series of the principal components from the clusters, with subsequent calculation of instantaneous amplitudes using the Hilbert transform. To ensure the stability of estimates of the waveforms of the EMD decomposition, 1000 independent additive realizations of white noise of limited amplitude were averaged before the Hilbert transform. Using a parametric model of the intensities of point processes, we analyze the connections between the instants of sequences of times of the largest local maxima of instantaneous amplitudes, averaged over the number of clusters and the times of earthquakes in the vicinity of Japan with minimum magnitude thresholds of 5.5 for the time interval 2012–2023. It is shown that the sequence of the largest local maxima of instantaneous amplitudes significantly more often precedes the moments of time of earthquakes (roughly speaking, has an “influence”) than the reverse “influence” of earthquakes on the maxima of amplitudes.

• Publisher: MDPI AG,MDPI
• Subject: Amplitudes / Analysis / Cluster analysis / Earth sciences research / Earth surface / earth surface tremor / Earthquakes / Eigenvalues / Eigenvectors / Estimates / event sequence intensity model / Geodetics / Hilbert transformation / Hilbert–Huang decomposition / Hydrology / Maxima and minima / Maximum likelihood method / Measurement / principal components / seismic process / Seismic waves / Sequences / Spectrum analysis / Time measurement / Time series / Tremors / Wave amplitude / Waveforms / White noise