Stromboli is an active insular volcano located in the Southern Tyrrhenian Sea, known for its persistent volcanic activity. Its northern submarine flank is characterized by two main shore-connected channels, with the head located at water depths less than 10 m and maximum distance of 100 m from the coast. In this study, we show the morphological evolution of these channels between 2021 and 2024 through the integrated analysis of repeated multibeam surveys and seafloor videos. The main seafloor changes are observed between May 2022 and March 2023 and related to the occurrence of retrogressive slope failures at the channel heads. These slope failures have been favoured by a rapid accumulation of volcaniclastic material transported by longshore currents. This high sediment supply has been, in turn, related to the interplay among increased eruptive activity along the NW flank of Stromboli, with several pyroclastic and lava flows reaching the sea, the occurrence of flash-flood events in the NE part of Stromboli Island and sea storms from westerly directions. The latter, mostly occurring during the autumn and winter seasons, can be considered one of the most plausible triggering mechanisms for the observed slope failures. The comparison of multibeam and seafloor videos shows a different evolution between the two shore-connected channels, mainly related to their different slope gradients and to the morphological confinement of sediment gravity flows. The formation and/or reworking (upslope migration) of upper-flow regime bedforms occur with slope gradients less than 13 degrees, while seafloor erosion dominates the evolution of the steeper and more confined part of the channels. These results highlight the importance of monitoring the shallow-water sector of active volcanic islands to better constrain the complex relationship between eruptive and sedimentary dynamics. Our observations also provide insights for the interpretation of channels and associated bedforms in the stratigraphic record of modern and ancient shallow-water volcaniclastic settings.
Active sedimentary dynamics and evolution of upper-flow regime bedforms in a shore-connected channel: A case-study from Stromboli volcano / Petronelli, D., Romagnoli, C., Pierdomenico, M., Saviano, S., Chiocci, F.L., Casalbore, D.. - In: MARINE GEOLOGY. - ISSN 0025-3227. - 498:(2026). [10.1016/j.margeo.2026.107794]
Active sedimentary dynamics and evolution of upper-flow regime bedforms in a shore-connected channel: A case-study from Stromboli volcano
Petronelli D.Primo
Writing – Original Draft Preparation
;Chiocci F. L.Funding Acquisition
;Casalbore D.
Writing – Original Draft Preparation
2026
Abstract
Stromboli is an active insular volcano located in the Southern Tyrrhenian Sea, known for its persistent volcanic activity. Its northern submarine flank is characterized by two main shore-connected channels, with the head located at water depths less than 10 m and maximum distance of 100 m from the coast. In this study, we show the morphological evolution of these channels between 2021 and 2024 through the integrated analysis of repeated multibeam surveys and seafloor videos. The main seafloor changes are observed between May 2022 and March 2023 and related to the occurrence of retrogressive slope failures at the channel heads. These slope failures have been favoured by a rapid accumulation of volcaniclastic material transported by longshore currents. This high sediment supply has been, in turn, related to the interplay among increased eruptive activity along the NW flank of Stromboli, with several pyroclastic and lava flows reaching the sea, the occurrence of flash-flood events in the NE part of Stromboli Island and sea storms from westerly directions. The latter, mostly occurring during the autumn and winter seasons, can be considered one of the most plausible triggering mechanisms for the observed slope failures. The comparison of multibeam and seafloor videos shows a different evolution between the two shore-connected channels, mainly related to their different slope gradients and to the morphological confinement of sediment gravity flows. The formation and/or reworking (upslope migration) of upper-flow regime bedforms occur with slope gradients less than 13 degrees, while seafloor erosion dominates the evolution of the steeper and more confined part of the channels. These results highlight the importance of monitoring the shallow-water sector of active volcanic islands to better constrain the complex relationship between eruptive and sedimentary dynamics. Our observations also provide insights for the interpretation of channels and associated bedforms in the stratigraphic record of modern and ancient shallow-water volcaniclastic settings.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
