Progradational sequences offshore the Volturno River mouth and their implications for marine geohazards

Progradational sequences are geological settings that may favor geohazards, rather than risks themselves. This is true for the prograding deposits offshore the Volturno River mouth and the surrounding shelf areas, located in the eastern Tyrrhenian margin. Based on the integration of multichannel seismic profiles of the VidePI Project with single-channel Sparker profiles recorded by the National Research Council of Italy, thick prograding seismo-stratigraphic units have been studied in detail, aimed at identifying the related marine geohazards. Despite the lack of significant slide scars and slide deposits, seismo-stratigraphic evidence has shown that creeping occurred in the upper seismo-stratigraphic units, rather than sediment liquefaction. The core difference is that creeping is an imperceptibly slow, gravity-driven movement of solid soil, while sediment liquefaction is a rapid, shock-induced transformation of wet sediment into a liquid-like state. Due to the lack of significant earthquakes in the area, controlling a possible sediment liquefaction, we suggest that creep is prevalent, as controlled by shallow gas pockets, representing a significant marine geohazard in the area. Onshore, the integration with literature data shows that rapid coastal erosion and a landward shift of the coastline occurred simultaneously. During the Holocene, the area was significantly impacted by human interventions that have conditioned the marine geohazards of this region. This study represents a valuable foundation for future tasks and planning and management of coastal and marine environments in this region.