The eastern slope of the southern Adriatic basin: a case study of submarine landslide characterization and tsunamigenic potential assessment

The southern Adriatic basin is the current foredeep of the Albanide fold-and-thrust belt that runs along the eastern boundary of the Adriatic basin and partly owes its remarkable water depth, deeper than 1,000 m, to the Mesozoic palaeogeography of the region. The eastern slope of the southern Adriatic basin is characterized by a thick stack of sedimentary prograding units, fed by sediments coming from the adjacent fold-and-thrust belt, which is still seismically active (e.g. 1979 Montenegro, M = 6.8). This slope presents extensive evidence of large-scale mass wasting throughout its Quaternary evolution and appears as a destructive slope system affected by progressive retreat. A submarine slide located along the eastern slope of the southern Adriatic basin has been recently characterized with good detail. The slide is of relatively small volume (0.031 km3) and shows a limited displacement, without major internal disruption. The small volume of the landslide combined with its relatively large water depth (headscarp at about 560 m and deposit at 700 m) result in a limited tsunamigenic potential, that has been assessed numerically by means of a Lagrangian block model as regards the slide motion and through a shallow-water finite-difference code for the tsunami waves propagation. Despite the almost negligible tsunami effects, the studied landslide can be taken as a lower case limit for other events along the scarp, and the observed features concerning the generated wave and its impact on the coast can be considered valid also for bigger events.