Permalink : http://hdl.handle.net/2115/44474

JaLCDOI : 10.14943/gbhu.73.195

Nonlinear site response was observed at TKCH 07 in Toyokoro and HKD 109 in Urakawa during the mainshock（Mj 8.0）and the largest aftershock（Mj 7.1）of the 2003 Tokachi-oki Earthqua ke． At TKCH 07, peak ground acceleration（PGA）was smaller than PGA at the other strong motion station in Toyokoro. At HKD 109, the accelerogram shows a characteristic spiky waveform. Due to this spiky wave, large PGA was observed compared to the other stations in Urakawa, although PGA at HKD 109 was smaller than PGA at JMA Urakawa station during the main shock and smaller aftershocks.