Submarine geohazard assessment based on regional seafloor mapping. Example from the Italian Project MAGIC (Marine Geohazards along the Italian Coasts).

Recent developments in seafloor imaging and mapping techniques greatly improved our capability of identifying marine geohazards affecting the continental margins. Geological processes ranging from volcanic activity to active faulting, from slope instability to bedform migration, are well documented on Italian continental margins and are potential geohazards for human settlements and infrastructures on the coast and offshore. A number of geomorphic features can be detected by high-resolution multibeam imaging and regarded as geohazard indicators the most common include slide scarps and deposits, canyon headscarps and steep erosional canyon flanks, fault-related seafloor relief, mud volcanoes, pockmarks, gravity flow deposits, erosional scours and bedforms indicating sediment mobility at different temporal/spatial scale. We discuss some of the most frequent problems dealing with reconnaissance, interpretation and cartographic representation of geohazardrelated submarine geomorphic features, with special reference to the National Mapping Project MAGIC (Marine Geohazards along the Italian Coasts).