New morphobathymetric and seismostratigraphic results on the north-western Ischia offshore (Naples Bay, Southern Tyrrhenian sea, Italy) and the emplacement of submarine slides in a volcanic setting

New morphobathymetric and seismostratigraphic results on the north-western Ischia offshore (Naples Bay, southern Tyrrhenian sea, Italy) are here discussed based on high resolution Multibeam bathymetry and Sparker seismic profiles recently collected in the frame of research programmes on marine geological mapping. An elevation versus average slope plot, highlighting where steep and flat areas occur in terms of elevation and referring to onshore Ischia volcanic edifice coupled to offshore areas, has been constructed to show main morphological features of Ischia. The Ischia island includes different morphological ranges, including the Ischia outcropping volcanic edifice, the continental shelf, the upper continental slope and the lower continental slope merging into the TYrrhenian bathyal plain. Large-scale volcanic avalanches occurring in the north-western Ischia offshore have been identified and described based on seismic interpretation. Seismic and morpho-bathymetric evidences provide new insights into the tectono-sedimentary evolution of the Ischia volcanic offshore and its relationships to volcanic structural collapses during the Late Quaternary.