2007 AGU Fall Meeting in San Francisco

Disaster Mitigation by Quick Response Against Strong Earthquake Motion

Yutaka Nakamura
System and Data Research, Co., Ltd.

The concept of EEW, earthquake early warning, was reported on San Francisco Daily Evening Bulletin on 3rd November 1868 by Dr. Cooper first for San Francisco area. According to him this idea was triggered by a failure of earthquake prediction. It is impressive that the thinking way is same as present. In 1982 more than 100 years later, the warning system for Tohoku Shinkansen realized the Cooper's idea for the first time on the world. After that, SAS for Mexico City started operating in 1991, and UrEDAS for Tokaido Shinkansen, an evolutional P-wave detection/warning system, began to operate in 1992. The UrEDAS technology is based on new concepts and methods to realize a real time system for estimating the earthquake parameters as magnitude, location and depth. In Japan at 1992, a new information service using UrEDAS technology had been prepared, but it was not born due to objection of JMA, Japan Meteorological Agency. By the same JMA, an information service, so called "Kinkyu Jishin Sokuho", will be broadcasted in nation wide from the first of October 2007. This implies that our UrEDAS Information Service plan has been correct, and it is my pleasure. However, it shall be rare case in Japan that JMA's information will reach faster than arriving of M7 class or less earthquake at the possible damaged areas, because it takes a time relatively long for processing and transmitting. Only for M8 class earthquakes of which the occurrence probability is about once in ten years in Japan, it is possible to receive the information before arriving of strong shaking in a possible damaged area far from the epicenter. JMA should popularize "Kinkyu Jishin Sokuho" after understandable explanation of these facts. I'm afraid that it will mislead people to broadcast a film on an evacuation training in unbelievable condition which is assuming an earthquake of seismic intensity 7 (corresponding to MMI scale XII) arriving 20 seconds later. Anyway, we can rely only on the onsite alarm in focal area. Accurate and quick earthquake information just after shaking is more useful than the late early warning. And I hope public organizations to make best effort that they can announce the earthquake information not only for main shock but also aftershocks, because these information is quite important for the quick response.

SESSION: S13 - Earthquake Early Warning: Design and Application Around the World


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