地震情報をどう生かすか

抄録

Disaster information systems have been drastically improved since the Great Hanshin-Awaji (Kobe) Earthquake occurred on January 17, 1995.
For example, the seismic intensity scales of the Japan Meteorological Agency were revised, and a new information system (commentary information and observation information) related to the Tokai Earthquake was introduced. Moreover, the Earthquake Investigation Research Promotion Headquarters of the Government which was established after the Great Hanshin-Awaji Earthquake, began to announce evaluations of aftershocks of major earthquakes and long-term evaluations of active faults in terms of probability.
When such information is disseminated to emergency organizations and general citizens, how should emergency organizations and general citizens interpret and respond to it. For instance, if an announcement that the probability of an aftershock of magnitude 6 is 20 % is disseminated, they will wonder whether that is high, and whether or not they should take countermeasures. It is necessary when Government organizations announce the probability of an aftershock that they comment on the degree of danger and the proper response to the expected aftershock.
Active fault activities were also more closely studied after the Great Hanshin-Awaji Earthquake. The Government selected 98 main active faults, and began research on their histories and possible future activities. As well as aftershocks, the results of predictions are announced in terms of probability over a 30-years. But the probability is low because active faults move once in 2000 or 3000 years. Therefore, announcing such results is likely to make inhabitants feel relieved. We must study how to disseminate such information for disaster mitigation.