えびの,吉松町における地盤の震動特性の調査(I)

Abstract

The observation of earthquakes and seismic prospecting were carried out in the damaged areaby Ebino Earthquakes in March, 1968. The method to estimate the vibrational characteristics ofthe ground and earthquake motions at the basic layer were investigated. The spectra of incidentwaves to basic layer were computed on the basis of those at the surface by use of inverse filters. In-verse filters were respectively estimated on the basis of actually measured S waves' distribution andassumed depth of the basic layer. The incident waves were t~omputed by use of simultaneouslyobserved seismograms at more than two places, 0.1-2.0 km apart from each other. In order thatthe amplitude spectra of incident waves coincide at those observation points, the geological struc-ture in respect to S waves and the basic layer must be appropriately assumed. This procedure wasmade by computer program.