[1] The Malta Escarpment represents the dominant morphological feature offshore eastern Sicily, linking the deep Ionian basin to the east with the Hyblean carbonate platform to the west. Interpretation of purposely acquired multichannel seismic data allows division of the Malta Escarpment into two portions characterized by different tectonic structures. Along the segment south of Siracusa the Malta Escarpment is not affected by recent faulting and appears as a steep surface that flattens out toward the Ionian basin. A recent deformation, characterized by a broad area of uplift, occurs 20-30 km east from the slope, along a NNW-SSE trend. The segment of the Malta Escarpment extending north of Siracusa, on the other hand, is characterized by the presence of NNW-SSE, east dipping recent extensional faults and related sedimentary basins. The observed structural features support the occurrence of a lithospheric tear between the Ionian oceanic basin and the Hyblean plateau.Citation: Argnani, A., and C. Bonazzi (2005), Malta Escarpment fault zone offshore eastern Sicily: Pliocene-Quaternary tectonic evolution based on new multichannel seismic data, Tectonics, 24, TC4009,

South-eastern Sicily has been affected by large historical earthquakes, including the 11 January 1693 earthquake, considered the largest magnitude earthquake in the history of Italy (<i>M</i>_w = 7.4). This earthquake was accompanied by a large tsunami (tsunami magnitude 2.3 in the Murty-Loomis scale adopted in the Italian tsunami catalogue by Tinti et al., 2004), suggesting a source in the near offshore. The fault system of the eastern Sicily slope is characterised by NNW–SSE-trending east-dipping extensional faults active in the Quaternary. The geometry of a fault that appears currently active has been derived from the interpretation of seismic data, and has been used for modelling the tsunamigenic source. Synthetic tide-gauge records from modelling this fault source indicate that the first tsunami wave polarity is negative (sea retreat) in almost all the coastal nodes of eastern Sicily, in agreement with historical observations. The outcomes of the numerical simulations also indicate that the coastal stretch running from Catania to Siracusa suffered the strongest tsunami impact, and that the highest tsunami waves occurred in Augusta, aslo in agreement with the historical accounts. A large-size submarine slide (almost 5 km³) has also been identified along the slope, affecting the footwall of the active fault. Modelling indicates that this slide gives non-negligible tsunami signals along the coast; though not enough to match the historical observations for the 1693 tsunami event. The earthquake alone or a combination of earthquake faulting and slide can possibly account for the large run up waves reported for the 11 January 1693 event

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