Local site amplifications in the town of Fabriano are determined from the data collected during the 1997 Umbria-Marche earthquake sequence. We have used a variant of the inversion technique proposed by Andrews  to simultaneously determine the local site amplification, the value of Q and the source spectra from observed waveform spectra. In an attempt to produce estimates of the site amplification as free as possible from the particular source-receiver geometry, we have extended the calculation of the spectral ratios to the coda. We have found that the estimates obtained from the coda window do not differ significantly from those obtained from the S—wave windows. Overall, the observed local site amplifications in Fabriano display a pattern of amplification which is sometime difficult to explain in terms of the mapped near surface geology.
Local site ampli …
AUTORI: Michelini A., Govoni A. RIG ANNO: 2000 NUMERO: 2 Numero di pagina: 118