Paleoseismic evidence of five magnitude 7 earthquakes on the Norcia fault system in the past 8,000 years (Central Italy)

Many large-magnitude faults (6.5≤ Mw ≤7.2) of the Italian Apennines are characterized by multi-century return times, so historical sources may have missed their last earthquake or other predecessors. Hence, even in Italy, where seismic catalogs among most comprehensive and time-extensive worldwide, there is a need for complementary studies that might fill lack information enhance knowledge concerning recurrence times destructive earthquakes. As paleoseismology discipline can do this, this study, we present results collected five new trenches opened along 33-km-long Norcia fault system (central Apennines) where, addition to historically known 1703 (Mw 6.9), uncovered indications four Holocene predecessor, with time 1,825 ± 420 years. Considering also paleoseismic already published on nearby Mt Vettore (2016 6.6), guess now hazard region could be assessed more robustly.