Vol.2 No.3 2009

Research paper : Evaluation of earthquake occurrence from active faults (T. Yoshioka)−183−Synthesiology - English edition Vol.2 No.3 (2009) prediction using other models had not met the demand of society, but in long-terms, the researches that address the mechanism of earthquakes are mandatory to increase the accuracy of prediction. Please state the relationship to these models objectively.On the other hand, for the issue of contributing to society through the mitigation of earthquake hazards a simple and general model is very effective, even if it includes the case with low prediction reliability. The author has exemplified it by the publication of the Rupture Probability Map of Major Active Faults in Japan. The response of society should be described more clearly as a demonstration of its efficacy.Answer (Toshikazu Yoshioka)In the Cascade Earthquake Model, the unique regularity is not taken into account for the co-movement of multiple behavioral segments. They can act together completely randomly. However, we did investigate through numerical simulation assuming that there may be some factor in the co-movement. I added some explanation.For the numerical simulation of dynamic rupture, the Active Fault Research Center investigated the co-movement of multiple fault rupture by dynamic rupture simulation, where various fault geometries were assumed. However, in this paper, the emphasis was placed on the use of the Cascade Model to explain the cyclic fault ruptures, and therefore, the description of dynamic rupture simulation was left to a citation of a reference.The Cascade Model is one of the models for cyclic fault rupture, and this model does not show the rupture process of the seismic center. Therefore, it does not conflict with the dynamic rupture model that shows the fault distribution form and the propagation of rupture using a numerical simulation, the physical model of earthquake occurrence process, or other models based on the observation/analysis of stress around the active fault and the understanding of geological structure. The models can coexist. I added in the text that the research to increase the prediction accuracy should be continued separately.On the response of society, I added the following description in the text: “As a result, the Rupture Probability Map of Major Active Faults in Japan obtained a certain degree of acclaim from the insurance industry, and we received several inquiries about using this assessment as basic data. It can be said that it is having some social impact.”


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