Large amplitude variations recorded by an on-fault seismological station during the L’Aquila earthquakes: evidence for a complex fault-induced site effect

Abstract

This study is focused on amplification effects observed at an on-fault station, FAGN, near L’Aquila. The difference in amplitude, compared to nearby stations, is extremely large for some particular events and neigligible for others of the same seismic sequence. FAGN is located on the S. Demetrio fault (Vezzani and Ghisetti, 1998) and the presence of the fault zone beneath the station could play a role on the observed amplifications (Davis et al., 2000; Cultrera et al., 2003; Karabulut and Bouchon, 2007). The fault-guided propagation effect is investigated through numerical modeling and analytical solutions by Ben-Zion and Aki (1990) and Ben-Zion (1998).