The 1-D and 2-D Seismic Modeling of Deep Quaternary Basin (Downtown L'Aquila, Central Italy)

Abstract

We compare the results of one-dimensional (1-D) and two-dimensional (2-D) modeling of the up-to-date geological section of downtown L'Aquila. The section transects a 300-m-deep Quaternary graben assumed as a “deep basin.” It is placed in the southern zone of downtown L'Aquila and is mainly filled up by silt and clay. The northern zone of downtown L'Aquila is conversely characterized by stiff rock (breccia superposed onto limestone). The study's aim is to validate this upgraded subsoil model and to investigate possible 2-D seismic effects. Considering both the experimental and simulated data, all the sites exhibit a clear resonance frequency (F0:0.4–0.6 Hz), and its amplitude (A0) decreases northward. The linear modeling is in good agreement with experimental data, confirming the subsoil model. In the southern zone, the A0 of the 2-D transfer function is higher than the A0 of the 1-D transfer function, which can be attributed to a bidimensional deep basin effect.