Explosion, earthquake, and ambient noise recordings in a Pliocene sediment-filled valley: Inferences on seismic response properties by reference-and non-reference-site techniques

The explosion data were collected in June 1990, as part of a crustal refraction experiment carried out in the Monti Vulsini volcanic area. A linear array of 13 digital stations was deployed orthogonally to the eastern border of the Radicofani graben: 2 stations were set up on a bedrock outcrop, whereas the remaining 11 were deployed on soft sediments, 100 m apart, along a straight line toward the center of the valley.

Explosion, earthquake, and ambient noise recordings were collected at the eastern edge of a Pliocene sediment-filled valley, nearby the town of San Casciano dei Bagni (Tuscany, Central Italy). The anomalous amplification of amplitudes (as high as a factor of 20 between sediment and hard-rock sites) shown by classical spectral ratios were compared with results obtained by using non-reference-site techniques, like that of Nakamura (1989) and its receiver-function-like extension.