Intermittent Slip along the Alto Tiberina Low-angle Normal Fault in
Central Italy
Abstract
The Alto Tiberina normal fault (ATF) in Central Italy is a 50 km long
crustal structure that dips at a low angle (15-20◦). Events on the fault
plane are about ten times less frequent than those located in its
shallower syn- and antithetic hanging-wall splays. To enhance ATF
catalogue and achieve a better understanding of the degree of coupling
in the fault system, we apply a template matching technique in the
2010-2014 time window. We augment by a factor 5 the detections and
decrease the completeness magnitude to negative values. Contrary to what
previously observed on ATF, we highlight intermittent seismic activity
and long-lasting clusters interacting with sequences on the shallower
splays. One of these episodes of prolonged seismic activity, detected at
the end of 2013 on a 30 km long ATF segment, suggest the ATF active role
during an aseismic transient unravelled by geodetic data.