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.