VAN Method Lacks Validity

In 1992, experts at the National Science Foundation Workshop titled "Low-Frequency Electrical Precursors to Earthquakes: Fact or Fiction?" concluded that "seismic electric signals observed in Greece are generated in the Earth, and the apparent correlation with earthquakes is promising" [Park, 1992]. On March 5 and 26,1993, strong earthquakes hit Pirgos City, Greece. Despite heavy damage, there was no loss of life because the citizens were prepared due to VAN predictions. In 1995, all of the three destructive M:6-class events were predicted and two important in­ ternational meetings on the subject were held. One was titled "A Critical Review of VAN," held jointly by the International Coun­ cil of Scientific Union's Scientific Committee for IDNDR and the Royal Society of London, of which the Proceedings is Lighthill [1996]. The other was a workshop, "Low Frequency Electromagnetic and Resistivity Precursors to Earthquakes," organized by H. F. Morrison at the University of California at Berkeley. In late 1997, when large earthquakes occurred after the 2.5-year quiescence, quite a few sci­ entists inquired about whether VAN had pre­ dicted them. The answer has been given earlier in this article. Thus interest in VAN seems to be growing steadily in the geoscience community. In Japan, signals highly suspect of being precursors have been observed [Lighthill, 1996] and we have embarked on a project to clarify the physics of crustal electromagnetic phenomena, covering a wide frequency range from DC to MHZ. The VAN method is one of the main targets of the project. Inland earth­ quakes can cause enormous devastation rela­ tive to their magnitude, especially when the epicenter is close to a major city. The electro­ magnetic methods seem to be effective for predicting this type of earthquake with a rela­ tively small number of stations, and therefore at small cost. Objective fundamental scien­ tific research on the electromagnetic phe­ nomena seems indispensable for the future.