Complexity of the 2009 L'Aquila earthquake causative fault system (Abruzzi Apennines, Italy) and effects on the Middle Aterno Quaternary basin arrangement

摘要: Abstract An Mw 6.1, devastating earthquake, on April 6, 2009, struck the Middle Aterno Valley (Abruzzi Apennines, Italy) due to activation of a poorly known normal fault system. Structural analysis population and investigation relationships with Quaternary continental deposits through integrated field laboratory techniques were conducted in order reconstruct long-term, tectono-sedimentary evolution basin hypothesize size segment. A polyphasic is characterized by conjugate, ∼E-W ∼N S-striking system, during early stage development, dip-slip, NW-striking system later phase. The old conjugate controlled generation largest sedimentary traps area responsible for horst graben structures within basin. During Early Pleistocene E-W N S reactivated dip-slip kinematics. This gave rise intra-basin bedrock highs significant syn-tectonic deposition, causing variable thickness hiatuses infill. Subsequently, since end Pleistocene, inception several NW-strands linked into longer splays their activity migrated toward leading segment affecting Paganica-San Demetrio basin: alignment. findings from this work constrain are consistent subsurface geometry inferred previous geophysical investigations. Notably, two major elements faults likely act as transfer nearby stepping active systems or form boundaries, geometric complexities, that limit overall length 19 ± 3 km. resulting coherent extent 6 2009 L'Aquila earthquake causative fault. positive match between geologic long-term coseismic images seismogenic highlights comprehensive reconstruction deformation history offers unique contribution understanding seismic potential.