Looking for surface faulting ancestors of the l'Aquila April 6, 2009 event: preliminary paleoseismological data and seismic hazard implications

Abstract

The occurrence of the Mw 6.3, April 6, 2009 earthquake has highlighted how critical is the knowledge of the location and of the characteristics of the active faults in a seismic region. This is true not only as a contribution to the seismic hazard assessment but also for the local planning of residential areas, plants and infrastructures. The 2009 earthquake occurred on the Paganica normal fault (PF hereinafter) and produced 3 km-long, maximum 0.1 m-high surface ruptures along its central section, as well as secondary slip along nearby tectonic structures and secondary effects such as liquefaction and landslides over a wide area.We will show the preliminary results from the analysis of a “special” site where an amazing “coseismic” trench, caved by the overpressure produced by the broken pipe of an aqueduct, provided the exposure of a 30-m wide fault zone of the PF, as well as from other cuts crossing the most recent scarp of the PF