Geohazard Features of the Ionian Calabrian Margin

Here we present a detailed description of different geomorphic features to complement the Maps of Geohazard Features of the Ionian Calabrian Margin produced by the Magic project (Marine Geohazard along Italian Coasts). Some of the most striking features we imaged are sources of widespread and recurrent geohazards. These include multiple coastal landslides, failure scars along open slopes, shelf-indenting retrogressive canyon headwalls and active fluid venting structures, that we investigated by integrating regional high-resolution multibeam sonar and sub-bottom profiling data. The main triggers and predisposing factors for the marine geohazards that we identify in our study area include frequent seismic activity, the rapid uplift of the margin since 1 Ma and the presence of Messinian evaporites at depth. Large-scale gravity-driven movements and the incipient retrogressive canyon headwalls are of particular concern, as they are located just a few hundred meters from the coast, where critical infrastructures and densely populated urban centers are situated, and also where high-resolution geophysical data are often lacking. Overall, our study provides a key reference for more detailed follow-up studies to foster a better understanding of marine geohazard occurrences. The insights provided are critical for planning monitoring programs and for the protection of coastal settlements and marine infrastructures along the Calabrian Ionian margin.