Site response using coda-wave techniques: Applications to short period data from central and southern Italy

The method of coda waves was applied to two different sets of data for the evaluation of the relative site response.The first set of data consists of low magnitude earthquakes with closely spaced locations, recorded at a small aperture array of velocimeters located in the Abruzzo region, central Italy. The second set of data is composed of events with epicentral distance ranging from 20 to 300 km, recorded at a seismological network with an aperture of about 100 km located in the Puglia region, southern Italy.Results show that the coda wave method furnishes stable estimates of the site effect. An amplification, relative to an arbitrary site, of a factor of about 2 occurs in the 1.7–6 Hz frequency band for two stations of the Abruzzo network, while an amplification factor of about 0.5 occurs in the whole frequency band (1–24 Hz) for one of the stations of the Puglia network. This station is located in an area which is correlated with a low macroseismic intensity anomaly.