Geohazard assessment of submarine canyon headwalls activity along the Ionian Calabrian and Apulian margin (Ionian Sea)

The Ionian Calabrian and Apulian margins are severely incised by a dense network of submarine canyon systems, that have formed in response to ongoing km-scale uplift of Calabria over the last ca. 1Ma. Despite their young age (Pleistocene) they incise the continental shelf and slope over lengths of tens of kilometres, with thalwegs up to 2 km wide, walls higher than 200m and headwalls, that can extend over more than 50 km.

Some of the canyon headwalls are very close to the coastline and in some cases, retrogressive features are observed from morphology and sub-bottom observations, representing a potential hazard for population and coastal infrastructures. Some of the canyons are isolated, others form hierarchic systems with five or more canyons merging into dendritic (cauliflower) systems that may or may not be connected to onshore drainage networks. They exhibit different characteristics in terms of headwall geometry, profile concavity and sinuosity.

We present new information on their geomorphic attributes to gain new understanding about the dynamic and evolution of the different canyon systems in the last 1Ma. In addition, we aim at extracting information regarding the grain size and sediment type from vintage backscatter geophysical data and subbottom data, to analyse canyon headwall enlargement and their erosive activity. The overall purpose of my study is to bring new insights about the inception and evolution of the different canyon systems in relation to tectonic and sea level changes and thus be able to assess the potential geohazards that retrogressive canyon headwalls may represent today for coastal areas and infrastructures.