Geoelectric variations related to earthquakes observed during a 3‐year independent investigation

Abstract

We present observations of the geoelectric field prior to some earthquakes. The data were collected during a three year (1992–1994) independent experimental investigation of VAN at the University of Patras Seismological Center. The recorded signals were: a) Gradual Variations of the Electric Field (GVEF), b) Periodic Variation of the Electric Field (PVEF), and c) Seismic Electric Signals (SES).

A Linear Modeling Approach on LTGP Signals and Seismic Activity

“…The produced models are derived from a portion of two third of the entire data set for each area and the rest measurements are used for validation. Figures 6-7 present the final value of the elements of matrices A and B of the four order LTI model of Area 3 . Figure 8 depicts the difference between real measurements and the produced values by the derived LTI model.…”

“…A great variety of precursor signals have been proposed through years, among which geoelectromagnetic ones, captured through geoelectrical measurements over a broad frequency spectrum, have been promising on an eventual prediction of damaging earthquakes [1], [2], [3]. Earthquake event occurrence can be considered as the outcome of preseismic geotectonic variations reflected on the geoelectric potential.…”

Untitled

“…Earthquakes' disastrous effects on human lives has motivated scientists putting more effort on earthquake prediction based on precursor events than on earthquake forecasting in a probabilistic manner. A great variety of precursor signals have been proposed through years, among which geoelectromagnetic ones, captured through geoelectrical measurements over a broad frequency spectrum, have been promising on an eventual prediction of damaging earthquakes [1], [2], [3]. Earthquake event occurrence can be considered as the outcome of preseismic geotectonic variations reflected on the geoelectric potential.…”

Extraction and selection of geoelectrical data features

“…While several approaches have been presented [1][2][3][4][5][6][7][8][9][10][11][12][13][14], it is still controversial whether seismic and geoelectric phenomena are related. This work describes a process used to initiate a similar analysis of Long Term Geoelectric Potential (LTGP) signals, the stage of extraction, evaluation, and selection of signal characteristics that appear correlated to seismic activity.…”