2025 Volume 25 Issue 3 Pages 3_20-3_39
It is important to reveal conditions of the places where destructive ground motions occurred. To reduce the risk of earthquake damage, especially when constructing important buildings, it is crucial to select a location where high-amplitude ground motions are unlikely to occur. In this report, we investigated a difference between places occurred seismic intensity 7 and 6 upper, using distances from a seismic fault of an inland earthquake, a shear wave velocity averaged upper top 30 m (AVS30), and a geomorphological classification. As a result, we summarized the following three requirements to occur seismic intensity 7. (1) AVS30 should be equal to or less than 500 m/s, (2) RJB should be equal to or less than 2 km; additionally, both ends of the fault are extended by 2 km, and (3) the geomorphological classification should not be reclaimed land. There was little possibility that seismic intensity 7 occurs at the place where even one of these conditions did not meet. We did not confirm that there was clear dependence of moment magnitudes up to M7 class in the range of RJB of the records of the seismic intensity 6 upper and 7.
