Analysis of multi-temporal DEMs and ortophotos for monitoring the morphological evolution of the Sciara del Fuoco slope during the 2002-2003 eruption of Stromboli volcano

On 30 December 2002, after a period of anomalous volcanic activity, the Sciara del Fuoco slope situated in the north-east flank of the Stromboli Island (Aeolian volcanic arc, Italy) was affected by a major landslide which detached the lava recently accumulated since the beginning of the eruption (28 December), together with a portion of subaerial and submarine deposits; consequently Tsunami waves, several meters high, affected the coasts the island. After the event, among the monitoring activities coordinated by Italia Civil Defence Department, systematic photogrammetric surveyes were carried out. Digital photogrammetry technique was used to rapidly process the collected data, thus obtaining high resolution Digital Elevation Models and corresponding ortophotos. The comparison of the data collected before the eruption and those acquired on 5th January 2003 concurred to define the geometry and to estimate the mass volumes involved in the slope failure of the Sciara del Fuoco subaerial portion. The following 13 photogrammetric surveys, from January to September 2003, made it possible to monitor the continuous and relevant morphological changes induced both by the lava flow and the evolution of the instability phenomena. The method adopted for the analysis of the acquired data and the results obtained (estimates of eroded and accumulated volumes, mean lava effusion rates, landslide features) are described in the paper