The ULF/ELF electromagnetic radiation before the 11 March 2011 Japanese earthquake

Abstract

The ULF/ELF short‐term electromagnetic precursor is discovered for the disastrous Japan earthquake (EQ) occurred on 11 March 2011. This analysis is based on the records measured by search coil magnetometers located at Nakatsugawa (geographic coordinates; 35.42°N, 137.55°E), Shinojima (34.67°N, 137.01°E), and Izu (34.64°N, 137.01°E) of the Chubu University network. The data of these magnetometers are extensively used to analyze the ULF/ELF seismo‐atmospheric radiation. It is then found that the ULF/ELF atmospheric radio emission is reliably detected on 6 March before the main shock on 11 March, probably as a precursory signature of the EQ. Further confirmation on its seismic origin was provided by the observational fact that the azimuths of the radiation source from all observation sites coincide approximately with the region of the forthcoming EQ.

Electromagnetic Precursors to the 2016 Kumamoto Earthquakes

“…There may be a few interesting electromagnetic phenomena in possible association Figure 1) [21]. The last, our own VLF/LF (very low frequency/ low frequency) network has been in operation for the last five years, and we currently have a network consisted of eight stations in Japan [22].…”

“…Here we will make full use of network observations of ULF magnetic field variations belonging to Japan Meteorological Agency (JMA), an ULF/ELF network by Chubu University [21], and our own VLF/LF subionospheric network [22].…”

Earthquake prediction with electromagnetic phenomena

“…So that, we hope to re-establish a new Tokyo ULF network, and new sensors at the stations at Chosi and Matushiro have already been installed this year, and the ULF data at those stations are being sent to a central data center in Tokyo. This new network will be reinforced by a few more stations, and will be used in collaboration with the similar network belonging to Chubu University (Nakatsugawa in Gifu prefecture), Shinojima (in Aichi prefecture) and Izu (Shizuoka prefecture)) (Ohta et al, 2013). We look forward to those data in near future with special attention to the direction finding of ULF radiation to locate the position of an impending EQ (Hayakawa et al, 2007).…”

On the Precursory Abnormal Animal Behavior and Electromagnetic Effects for the Kobe Earthquake (M~6) on April 12, 2013

“…Figure 3 illustrates a summary of the temporal evolutions of the abnormal animal behavior as studied in this paper, ULF radiation [27] (conventional statistical analysis), ULF radiation (non-conventional critical analysis) [28], ELF (extremely low frequency) radiation [31], ULF depression (as a signature of lower ionospheric perturbation) [32] and VLF propagation anomaly indicative of the lower ionospheric perturbation [33] [34]. In the first row, we observed the abnormal depletion of the milk yield of cows around 3 April.…”