 Fluctuations in the MT signal may be able to predict the onset of seismic events.Stationary MT monitoring systems have been installed in Japan since April 1996, providing a continuous recording of MT signals at the Wakuya Station (previously at the Mizusawa Geodetic Observatory) and the Esashi Station of the Geographical Survey Institute of Japan (GSIJ).These stations measure fluctuations in the Earth's electromagnetic field that correspond with seismic activity.