5:15 PM - 6:30 PM
[MIS34-P77] Characteristics of earthquake ground motions in the Kumamoto City, using the aftershock observation data of the 2016 Kumamoto Earthquake
Keywords:Aftershock observation, 2016 Kumamoto earthquake, Kumamoto City
Accelerations at 6 stations for an earthquake occurred at Aso were variety in the phase and the amplitude at the southern site was larger by a factor of 2 than one at the northern site. The earthquake ground motion at the southern site were amplified by a factor of 3 for a period of 0.5 second and by a factor of 2 for a period of 1 second, comparing to the earthquake ground motion at the northern site. The various levels of ground motions from small to large earthquakes, including the earthquake (Mj 7.3) occurred on 4/16/1:25, were recorded at 2 stations in the southern sites. In those velocity responses, the dominant period of 0.8 and 1.2 seconds were appeared at velocity response of 0.1 cm/s and 30 cm/s, respectively. In case of the large earthquake (Mj7.3), the nonlinearity of soft-soil was suggested by the dominant period of 2.2 seconds at velocity response of 120 cm/s. The earthquake records at 2 southern sites which are 600m far had a large difference for a period of 1 to 2 seconds. In the future, we will investigate the characteristics of earthquake ground motions at those 2 sites.