Introduction to Seismic Electric Signals

Identifying the occurrence time of an impending major earthquake: a review

“…2b) on 14 January 2008 at the station PIR of the VAN telemetric network (Fig. 3) operating in Greece (Varotsos et al 2008a). Furthermore, a longer duration SES activity of the same polarity and amplitude was recorded also at PIR (depicted in Fig.…”

“…in Greece only when expected M is 6.0 or larger, a prediction is publicized). Thus, a prediction was publicized on 1 February 2008 by Varotsos et al (2008a) in the www.arXiv.org database of the library of Cornell university.…”

“…The study of the seismicity in natural time was immediately started in the area A: N 38:6 36:0 E 22:5 20:0 (which had been determined on the basis of SES properties by means of the procedure described above) as publicized on 1 February 2008 by Varotsos et al (2008a). This area is marked with the red line in Fig.…”

“…3), the magnitude and the occurrence time were specified and announced publicly in advance. , which was the expected epicentral area (Varotsos et al 2008a). Solid dots show the stations of the VAN telemetric network 3 Identifying the occurrence time of a major earthquake when geoelectrical data are lacking…”

Entropy in Natural Time and the Associated Complexity Measures

“…Seismic Electric Signals [12,[32][33][34][35] (SES) are low-frequency (≤ 1 Hz) variations of the electric field of the Earth that have been found in Greece [36][37][38][39][40] and Japan [41][42][43][44][45] to precede earthquakes. Many SES recorded within a relatively short time are termed SES activities and usually exhibit a dichotomous behavior, see Fig.1(a).…”