トルコにおける地震被害の発生と減災に関する研究 : 2.震度分布予測・評価式の構成

抄録

This paper introduces two approaches for deriving empirical equations of seismic intensity distribution law. The first one is a rough estimation of spatial intensity distribution. The extension of area with a given intensity was evaluated by means of the least squares method using the Turkish earthquake data in recent 50 years. It was found that earthquake magnitude is the most influential factor, except for the time-dependent field determination criterion of intensity and that seismic intensity attenuates with distances more rapidly in Turkey than in western United States and in Japan. Brief examination of isoseismal configuration shows that isoseismals of higher intensities are more elongated in shape and that the fault length approximately corresponds to the major axis of intensity VIII or IX. The second approach is more precise evaluation of seismic intensity from site to site at short-to-moderate epicentral distances. Based upon an advanced model considering seismic source parameters such as fault configuration, size and slip displacement, isoseismals of the 7 recent earthquakes (M_s>__-6.0) with maximum intensity of VIII or IX were studied and a better empirical equation was obtained.