Morphologic resilience and depositional processes due to the rapid evolution of the submerged Sciara del Fuoco (Stromboli Island) after the December 2002 submarine slide and tsunami

In order to monitor the Stromboli submarine slope after the 30 December 2002 landslide and tsunami, repeated marine surveys were carried out offshore of Sciara del Fuoco. The morphological changes and depositional processes that brought to the gradual filling of the slide scar have been studied in detail. Thirteen surveys in a period of little more than 4 years provided a unique opportunity to reconstruct the morpho-sedimentary evolution of the submarine slope and its recovery after the mass-wasting event. The scar has been progressively filled with lava and volcanoclastic debris: ill the first month and a half, the filling rate was very high due to the entrance of lava flows into the sea and to the morphological readjustment of the slope: in the following months/years the rate dramatically decreased when the eruptive vents moved upwards and the eruption finally stopped. After 4 years (February 2007) more than 40% of the scar was, already filled. In early 2007, a new eruption Occurred and a lava delta Was Constructed in the 2002 scar. influencing the natural readjustment of the slope: therefore, Our reconstruction only encompasses the period between the 2002 and 2007 eruptions. The swath bathymetry reconstruction of geometry and volume of scar filling, during the period 2002-2007 evidenced a Punctuated and fast shift of depocenters and debris emplacement through avalanching processes. This process quickly obliterated the features produced by the 2002 tsunamigenic landslide so that a major question about the preservation potential of mass-wasting features oil active volcanic flanks emerges. (C) 2008 published by Elsevier B.V.