SEGJ Technical Conference

A Ultrahigh Density Questionnaire Seismic Intensity Survey and ground vibration characteristics by microtremor observations in the central area of Maesawa Town of Oshu City, Iwate Prefecture, of the 2011 off the Pacific coast of Tohoku Earthquake and the aftershock occurred at April 7

Abstract To clarify the vibration characteristics in the central area of Maesawa District, Oshu City of Iwate Prefecture, the survey of seismic intensity was done using questionnaires for both the 2011 off the Pacific coast of Tohoku Earthquake and the aftershock occurred at April 7, 2011. However, in the area many houses were damaged by the aftershock. JMA reported that the seismic intensities at the observation site of Maesawa Town of Oshu City were 6 weak for the main shock and same for the aftershock. And, microtremor observations were done at 28 points where seismic intensity were estimated, using a three-component seismometer. Averaged amplitudes, predominant periods and H/V spectra of observed microtremors were examined.