COMPARISONS WITH SITE AMPLIFICATIONS AND S-WAVE IMPEDANCE OF THE UPPERMOST SURFACE LAYER AT SOMA CITY

Abstract

 During an earthquake occurred at off coast Fukushima in March 16, 2022, damages have occurred especially in Soma port and north area of Matsukawaura. We observed aftershock motions at several sites in Soma city in order to evaluate site amplifications where damages have occurred. It is found that almost all the sites show peak frequencies around 0.6 Hz and that the damaged sites show large peak amplitudes. It is also found that peak amplitude values have good relations with S-wave impedance values of the uppermost surface layer.