The use of subionospheric VLF/LF propagation as the means to study ionospheric perturbations associated with earthquakes

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.