High-resolution controlled-source seismic tomography across the Middle Aterno basin in the epicentral area of the 2009, Mw 6.3, L’Aquila earthquake (central Apennines, Italy)

摘要: We present high-resolution Vp models of the Middle Aterno basin obtained by multi-scale non-linear controlled-source tomography.Seismic data have been collected along four dense wide-aperture profiles, that run SW-NE for a total length ~6 km in hangingwall Paganica-S. Demetrio Fault, source 6th April 2009 (Mw 6.3) L'Aquila normal-faulting earthquake. Seismic tomography expands knowledge with high spatial resolution and depth penetration (>300 m), illuminating Meso-Cenozoic substratum corresponds to high-Vp regions (Vp>3500-4000 m/s).Low (1500-2000 m/s) lacustrine sediments (Early Pleistocene age) are imaged only SW sector basin, where they up 200 m thick lie below coarse fluvial alluvial fan deposits. The overall infill consists Early Holocene between Paganica Fault Bazzano ridge, reaching 3000 m/s oldest conglomeratic bodies. has an articulated topography. main depocenter, ~350 deep, is south ridge. Remarkably, this depocenter overlying body match area maximum coseismic subsidence observed after In area, images unravel large steps related two unreported SW-dipping buried strands, synthetic ~250 associated vertical throw. This finding important implications on long-term history system, whose displacement previously underestimated. An additional offset complex Quaternary extensional structure should therefore be considered.