VHF-electromagnetic evidence of the underlying pre-seismic critical stage
© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2002
Received: 20 February 2002
Accepted: 26 November 2002
Published: 21 June 2014
Based on the study of pre-seismic very high frequency (VHF) and very low frequency (VLF) electromagnetic signals, we attempt to establish a set of necessary conditions referring to the underlying critical stage of the earthquake preparation process. This study combines concepts from spectral analysis associated with critical point hypothesis, results from laboratory experiments of rupture and seismological arguments. These conditions are fully satisfied in the case of the VLF-VHF pre-seismic signals associated with the Kozani-Grevena earthquake in Greece.