Experimental measurement of electromagnetic emissions possibly related to earthquakes in Japan

Abstract

Recent observations in the USSR appear to suggest that wide‐band electromagnetic radiation occurs just prior to earthquakes. To apply this phenomenon to earthquake prediction, measurements have been carried out at the Sugadaira Space Radiowave Observatory in Japan under the USSR‐Japan Cooperation Program in 1980. The recorded noise level at 81 kHz is comparatively quiet throughout the day and night. However, about one‐half hour before the main shock of a magnitude 7 earthquake at 0733 UT on March 31, 1980, the instrument recorded an anomalous amplitude increase to 15 dB higher than the normal level. VLF data recorded synoptically at Sugadaira suggest that unusual impulsive radiation at frequencies below 1.5 kHz also occurred shortly before the earthquake. Similar 81‐kHz emissions were observed prior to magnitude 5 and 6 earthquakes on September 25, 1980, and January 28, 1981.

The dynamics of the stress state in Southern California based on the geomechanical model and current seismicity: Short term earthquake prediction

“…Among these studies we note the theoretical works [BenZion, 2001;Ben-Zion and Rice, 1995;Rice, 1983;Sobolev, 1993]. In parallel, earthquake forecasting methods have been developed [Bondur and Zverev, 2005a, 2005b, Gokhberg et al, 1995Jordan, 2006;Keilis-Borok and Soloviev, 2010;Keilis-Borok et al, 2004;Molchan and Keilis-Borok, 2008].…”

“…The reason of the earthquake, that is the earth crust deformation, and different anomalous phenomena are related to each other via some unknown coefficient or, more precisely, via some complicated matrix. [Bondur and Kuznetsova, 2005;Bondur and Pulinets, 2012;Bondur and Smirnov, 2005;Bondur and Zverev, 2005a, 2005bGokhberg et al, 1982;Sobolev, 1993;Varostos et al, 1981].…”

“…Thus, for example, considering electromagnetic precursors, one should know mechanics-electromagnetic transformations, which should occur in different crust layers with different conductivity, porosity, permeability, fluid saturation, elasticity and so on [Gokhberg et al, 1982].…”

Stochastic consideration of relationship between occurrences of earthquake and fluctuations in the radio wave propagation

“…Geophysical electromagnetic phenomena can be observable by using electromagnetic wave propagation. Almost reports on the geophysical electromagnetic phenomena are 15 classified into two groups, direct observations (Gokhberg et al, 1982;Smith et al, 1990;Hayakawa et al 1996) or indirect observations (Fujiwara et al, 2004;Hayakawa et al, 2010).…”

Changes in total electron content associated with earthquakes (M > 5) observed from GPS station, Varanasi, India

“…After the pioneering work of Gokhberg et al (1982), active earthquake prediction studies started by monitoring the electromagnetic waves associated with earthquakes. The primary mechanisms for the generation of electric and magnetic fields during crustal deformation and earthquakes include the piezoelectric effect, the triobo-electric effect and the electro-kinetic effect (Dobrovolsky et al 1989, Sornette andSornette 1990).…”