A Report from the RIKEN International Frontier Research Project on Earthquakes (IFREQ)

Abstract

ABSTRACT1 Earthquake Prediction Research Center, Tokai University, Shizuoka, Japan * Corresponding author address: Prof. S. Uyeda, Earthquake Prediction Research Center, Tokai University, Shimizu Orido, Shizuoka, Japan; Mitigation of seismic hazards requires integration of science and human action, namely the science of earthquakes, anti-seismic engineering and socio-political measures. In this paper, we will be primarily examining the problem of saving human life from earthquakes. Loss of human life from earthquakes is caused overwhelmingly by the collapse of houses and buildings within less than a few minutes of the main shocks. When structural damage is reduced, most other seismic hazards will also be reduced. On top of that, if short-term prediction could be made, casualties would be further reduced dramatically. We review the state of the art in short-term prediction, in particular recent progress in approaches using electromagnetic phenomena.The RIKEN International Frontier Research Project on Earthquakes (IFREQ) has demonstrated the existence of pre-seismic ultra-low frequency (ULF) geo-electric potential changes, a claim that has long been made by the Greek VAN group. In addition, IFREQ has been able to verify the precursory signatures of ULF geomagnetic variations. A review is also made for another promising method using pre-seismic over-the-horizon transmission of VHF (~100MHz) FM radio waves. Thus, the reinforcement of existing structures and enhancement of short-term prediction research are the two keys for seismic hazard mitigation.

ULF Geomagnetic Changes Associated with Large Earthquakes

“…16 is the global summary of the investigation on the pre-seismic ULF magnetic changes, showing the empirical relationship between M of EQ and epicentral distance of ULF stations. Pre-seismic ULF emissions would be detected for M > 4.5 EQs which roughly satisfy 0.025R < M -4.5, where R is epicentral distance (Uyeda 2003;Hattori et al 2004a). …”

“…Electromagnetic phenomena are now considered a promising candidate for short-term prediction of large earthquakes (e.g., Hayakawa and Fujinawa 1994, Hayakawa 1999. Research stimulated by Japan's two earthquake Frontier Projects [International Frontier Research on Earthquakes by the Institute of Physical and Chemical Research, hereafter known as RIKEN (Uyeda 2003) and Earthquake Remote Sensing Frontier by the National Space Development Agency of Japan, hereafter known as NASDA (Hayakawa 2001)], has led to an accumulation of observational reports on earthquake-related electromagnetic studies in a very wide frequency range all over the world.…”

Influence of Lightning on the Observation of Seismic Electromagnetic Wave Anomalies

“…After the 1995 Hyogo-ken Nanbu earthquake, RIKEN initiated the International Frontier Research Program on Earthquakes in October, 1996. This program was aimed at basic research for earthquake prediction by utilizing electromagnetic methods (e.g., earth current) (Uyeda et al , 2004Nagao et al 2000). Our observation system was adopted in this program and several observation systems were installed in the Tokai and Kanto regions.…”

Preminary Results of the iSTEP Program on Integrated Search for Taiwan Earthquake Precursors

“…Although seismic waves are the most obvious manifestation, earthquakes may be accompanied or preceded by signals of a different nature -electric, electromagnetic, or luminous -that may help forecasting impending seismic activity (Uyeda 2004;Freund 2000). After the disastrous 1995 Kobe earthquake in Japan, the Science and Technology Agency of Japan called for the "Earthquake Integrated Frontier Research" project.…”

“…After the disastrous 1995 Kobe earthquake in Japan, the Science and Technology Agency of Japan called for the "Earthquake Integrated Frontier Research" project. It started in 1996 to study extensively the whole spectrum of seismo-phenomena taking place in the atmosphere and ionosphere/magnetosphere and then to investigate energy transfer from the lithosphere to the atmosphere and ionosphere/magnetosphere (Uyeda 2004). We analyzed ionospheric foF2 and found three clear precursors appearing about 1, 3, and 4 days prior to the Chi-Chi earthquake.…”