The offshore margin of Mt. Etna has been shaped by Middle Pleistocene to Holocene shortening and extension and, more recently, by gravity-related sliding of the volcanic edifice. These processes have acted contemporaneously although the gravitational component largely prevails over the tectonic one. In order to investigate this issue, we focused on the main role of active tectonics along the south-eastern offshore of Mt. Etna by means of marine high-resolution seismic data. Seismic profiles revealed post-220 ka sedimentary deposits unconformably overlaying the Lower-Middle Pleistocene Etnean clayey substratum and volcanics of the Basal Tholeiitic phase and the Timpe phase. Offshore Aci Trezza-Catania, the architecture of the sedimentary deposits reflects syn-tectonic deposition occurred into “piggy-back” basin setting. Shortening rate was estimated at ~0.5 mm/a since ~220 ka. Asymmetric folding also involves post Last Glacial Maximum deposits, evidencing that compressional deformation is still active. In the continental slope, a belt of normal faults offset the Lower-Middle Pleistocene Etnean clayey substratum and younger deposits, also producing seafloor ruptures. Thrust and fold structures can be related to the recent migration of the Sicilian chain front, while extensional faults are interpreted as part of a major tectonic boundary located in the Ionian offshore of Sicily.

Volcanic‐intrusive complexes often formed along lateral slab edges as a consequence of subduction‐induced mantle flow. We investigate this process in the southern Tyrrhenian Sea by integrating multibeam bathymetry, seismic‐reflection data, regional magnetic anomalies data, and seismological data. The interpretation of the data highlights the presence of magmatic intrusions that locally reach the seafloor forming volcanic edifices. Chimneys, lava flows, and laccoliths are observed beneath and surrounding the volcanoes. The emplacement and cooling of the magma occurred during the Brunhes Chron. The volcanoes are not active even if the hydrothermal activity occurs. The volcanic‐intrusive complex can be subdivided in a western domain (Diamante and Enotrio seamounts) where strike‐slip transpressional faults deform the volcanic edifices and an eastern domain (Ovidio volcanic seamounts) characterized by flat‐topped volcanic edifices. The flat‐topped morphology is the result of the interplay between volcanism, erosion, sedimentation, and sea‐level change. The Ovidio volcanic seamounts formed in an area that experienced at least 60 m of subsidence. Magnetic signatures over the northern side of the Ovidio and Diamante seamounts highlight the presence of a deep‐rooted, magnetized feeding system remnant. Volcanic edifices extend above a magma feeding system, characterized by low Vp/Vs ratios. The Diamante‐Enotrio‐Ovidio volcanic‐intrusive complex formed as a consequence of the ascent of subduction‐induced mantle flow originated in the northern‐western edge of the retreating Ionian slab. We speculate that the magma ascent was controlled by a strike‐slip deformation belt, which accommodated the bulk of the shear strain resulting from the formation of a roughly E‐W trending, Subduction‐Transform Edges Propagator fault.

Using seismic reflection profiles and bathymetric data, we analyzed the stratigraphy and tectonics of the Paola Basin, providing information on the dynamic of the forearc of the Tyrrhenian‐Ionian subduction system. The Paola Basin is a NNW‐SSE trending syncline, bounded by the Coastal Chain to the east and the Paola Anticline to the west. It hosts up to 5.2 km thick Plio‐Quaternary deposits, most of them supplied from Apenninic/Sila entry points and transported by longshore currents. The total subsidence reaches a value of ∼5 km. The sedimentary load varies from 60% to 75% of the total subsidence. The Pliocene to Lower Pleistocene sedimentary infill of the syncline displays a strata growth geometry consistent with a continuous rotation of the eastern limb of the Paola Anticline. Crustal folding can explain both the tectonic subsidence of the Paola Basin and the uplift of the Paola Anticline. To the east of the basin, Late Pliocene to Early Pleistocene growth of the central sector of the Coastal Chain led to the definition of the Paola and Crati basins, previously connected in a larger proto basin. The trench‐parallel component of the plate movement was accommodated by a strike‐slip zone, with associated releasing and restraining bends coinciding with the Paola Anticline. The bathymetric expression of the strike‐slip zone consists of structural highs and depressions that overall form the Paola Ridge. Since the Middle Pleistocene, the growth of the Paola Anticline and Paola Basin came to an end and extensional tectonics controlled the evolution of the forearc region.