Deep reaching versus vertically restricted Quaternary normal faults: Implications on seismic potential assessment in tectonically active regions: Lessons from the middle Aterno valley fault system, central Italy

摘要: Abstract We investigate the Middle Aterno Valley fault system (MAVF), a poorly investigated seismic gap in central Apennines, adjacent to 2009 L’Aquila earthquake epicentral area. Geological and paleoseismological analyses revealed that MAVF evolved through hanging wall splay nucleation, its main segment moving at 0.23–0.34 mm/year since Pleistocene; penultimate activation event occurred between 5388–5310 B.C. 1934–1744 B.C., last after 2036–1768 B.C. just before 1st-2nd century AD. These data define hard linkage (sensu Walsh Watterson, 1991 ; Peacock et al., 2000; 2003 , references therein) with contiguous Subequana segment, able rupture large magnitude earthquakes (up 6.8), did not about two millennia. By joint analysis of geological observations seismological acquired during 2009 sequence, we derive picture complex structural framework area comprised MAVF, Paganica (the causative fault) Gran Sasso Range. This sector is affected by dense array few-km long, closely regularly spaced Quaternary normal strands, are considered as branches northern segment. Our reveals these structures downdip confined decollement represented presently inactive thrust sheet above front limiting their seismogenic potential. study highlights advantage combining field high resolution fully unravel setting regions where subsequent tectonic phases took place interference plays key role influencing seismotectonic context; this has also inevitably implications for accurately assessing hazard such structurally regions.