The earthquake April 6th 2009 and the present knowledge of the active faults in the Central Apennines

The Aprii 6'h, 2009 earthquake hit a portion of the Apennines chain where severa I active Faults, with potential fa r M up to 7 earthquake" exi,t. These faults inlersect the surface as elements of va riable length, but not exceeding 20 km. The short sections show generatly an en-echelon organizotion and are port of longer fault systems le.g. Upper Aterno Valley, Campo Imperatore, Fucino systems) . These systems are interpreted as the eomplex surfaee expression of individuai fault piane, at depth. Thi, , tructu ral complexity represents an intrinsic diffieulty for the definition of a reliab le fault segmentation model for the area, and in parlicular for the estimate of geometry and magnitude of potenlial seismic sources. In this paper we diseuss the structural eomplexity and the problem, related to the definition of the seimogenic behavior of active faults in a wide area centered on !he Aprii 6~ earthquake. We firsl provide a short introduction to the neoteetonic, of the area and methodological background, thus, we deseribe the active faults thol represenls the surfoee expression of the seismic ,auree, at depth. The final part focu, on the faul!lsource re'pon,ible far the Aprii 61h earthquake and di,cuss the problem, related to the definition of the seismie behavior of the area.