Great Achievement of Japan on Seismic Hazard and Prediction in the Last Three Decades

Japanese seismologists were active in almost every aspect of seismological research during the last three decades. The recent researches in Japan (as of 1993) are summarized in Special Issue of Journal of Physics of the Earth (Vol. 43, Nos. 3-5, 1995). Special Issues of Zisin (J. Seism. Soc. Japan), Vol. 44 (1991) and Vol. 50 (1998) carrying 30 and 24 review papers and several other review papers in the same journal during the 1990s are also useful to evaluate recent seismological researches in Japan, but these are written in Japanese. In recent years, more than 300 papers have been presented at every meeting of the Seismological Society of Japan held twice a year. I only cite some of the research objectives for which Japanese seismologists have made significant achievements.

Urgent Earthquake Bulletin service

Distribution of Japan Railway’s Alarm Seismometers*

* Courtesy of Dr. Y. Nakamura

1. Dense telemetered seismic networks including the cable type OBS stations.

2. Dense networks of digital strong motion seismographs.

Area Mail system sends signals quicker

than the earthquake can move.

3. Quick determination of source parameters and early warning system.

4. Broadband seismic networks in the western Pacific area.

OceanNet buoy

5. Recurrence patterns of earthquakes from active faults, marine terraces, tsunami deposits, historical   earthquakes, etc.

6. Earthquake sequences, seismicity patterns, and probability of earthquake occurrence.

7. Earthquake triggering by stress changes by tides, earthquake dislocations, etc.

8. Earthquake precursors in geochemical, hydrological, geodetic, electrical, and seismic  data.

9. Simulation of strong ground motion waveforms.