Abnormal behaviour of some parameters revealed in the Georgian SSR before the Armenia earthquake of December 7, 1988: a preliminary report

Summary For more than ten years several measurements sites able to detect geophysical and geochemical precursory phenomena of earthquakes have been working in Soviet Georgia. On the occasion of the destructive Armenia earthquake of December 7, 1988 (M=6.9) premonitory signals relative to geophysical and geochemical parameters seem to be observed. In this paper anomalous variations of the water level in a well, of the helium content in thermal waters and of the electromagnetic signals in air, obtained in three measurements sites located at about 80 km from the epicentre, are reported. These variations appear beginning from about a month up to some hours before the occurrence of the earthquake and it seems reasonable to consider them as short-time or very short-time precursory phenomena of the earthquake.