Abstract
To understand site effects within Hiroshima prefecture, predominant periods of the ground in the linear condition and during the 2001 Geiyo earthquake were estimated from microtremors and seismic motion at site of K-NET, KiK-net and Seismic Intensity Information Network. Conclusions were obtained as follows:(1) the H/V spectra were able to estimate the predominant period of the ground stably,(2) although predominant periods at most sites were shorter than 0.4s, those at several sites in sedimentary basins in southern region were longer than 0.6s, and (3) strong nonlinear behavior of the ground occurred at many sites during the main shock.
