R. Azzaro (CNR-GNDT c/o Istituto Internazionale di Vulcanologia, piazza Roma 2, 95123 Catania, Italy)

E. Vittori, L. Ferreli, A. M. Michetti, L. Serva (CNR/GNDT c/o ANPA, via Vitaliano Brancati 48, 00144 Roma, Italy)

Fault capability is the high probability of significant surface displacement in the near future generally, but not necessarily, associated to earthquakes. This concept is more useful to hazard analysis than the generic definition of fault activity. The Pernicana fault is located in the north-eastern flank of Mt. Etna, bordering to the north the most mobile sector of the volcano affected by flank instability processes. Its kinematics is dip to oblique normal along the uppermost segments near the NE Rift zone. To a lower altitude, the fault presents left-lateral motion. Earthquakes of low magnitude (< =4.2) but high intensity with associated surface faulting (due to shallow focal depths) occur in the western sector of the fault whereas in the eastern one, downhill near the coast, aseismic creep seems to dominate. The case of this fault is effectual to illustrate the damage expectable from capable faulting, because of its continuous and high rate of slip and its location across urban areas. In fact, buildings, roads and other essential lifelines are affected by slow, left-lateral displacement determining severe damage and high risk in the near future. The Pernicana fault is only one of a set of tectonic structures in the Etnean area posing severe hazard in the densely urbanized territory north of Catania. Outside the Etna volcanic region fault capability is generally associated with high magnitude earthquakes (>= 6.5), based on historical and palaeoseismological data. This source of hazard, still poorly considered by local planners and technicians, must be taken into due account for hazard reduction programs.