Electromagnetic phenomena associated with earthquakes: Review

Abstract

NASDA (National Space Development Agency of Japan) has just finished the Earthquake Remote Sensing Frontier Project (for which the author was the principal scientist) conducted since 1996 within the framework of the Earthquake Frontier Projects by the former S.T.A. (Science and Technology Agency). Main emphasis of NASDA's Frontier Project was the complete understanding of lithosphere-atmosphere-ionosphere (LAI) coupling by making full use of different kinds of observational items and finally we would like to contribute to the short-term earthquake prediction. The most exciting finding from our Frontier project was the discovery of convincing evidence of the presence of seismo-ionospheric perturbations, which has been extensively investigated by using the subionospheric VLF/LF propagation, and several important findings have been presented, including the initial result for the Kobe earthquake and a few case studies from many data. Then, our latest result on seismo-atmospheric perturbation is presented on the basis of the reception of over-horizon FM transmitter signal. Finally, the initial and boundary condition of the LAI system (i.e., lithosphere) has been investigated by means of the measurements of ULF (ultra-low-frequency) emissions and acoustic emissions, whose latest results are summarized as well.