Stability of the submarine slope of the Tiber River delta

On the very gentle slope of the Tiber River prodelta. high resolution seismics depicted seat1oor undulations and a wavy pattem of near-surface reflectors over an area of about l00 km2. These features appear to be deformed according to listric surfaces thus suggesting the instability of a wedge of sediments up to 30 m thick. Physical and mechanical characterization of the prodelta soft muddy sediments was carried out on gravity cores aligned on a transect parallel to the slope. The quantitative assessment cf stability conditions was performed by means of stability analyses which have taken into account the effect of active sedimentation and of dynamic loading induced by sea waves and earthquakes.