Microwave interferometric sensors as a tool for space and time analysis of active volcano deformations: The Stromboli case

A Ground Based SAR Interferometer (GB-InSAR) was installed at Stromboli volcano (Italy) in February 2003 to continuously monitor the behaviour of the morphological depression known as Sciara del Fuoco, SdF, with alerting purposes. This was decided as a consequence of the collapse of a large landslide from the NW slope of the SdF and the subsequent tsunami occurred on December 2002. The GB-In SAR system, working at Ku band, was set up on the stable right flank of the SdF; it has been continuously working and during this last five years has permitted to follow the temporal and spatial evolution of the mass movement in the SdF and the crater. Interferometric maps have permitted to assess the deformation field over a large portion of the target area and to characterize different processes. The system allowed to observe in particular two main events occurred on 5 April 2003 (a major explosion) and on 27 February 2007 (beginning of the effusive phase) respectively. The potential of the use of DInSAR from satellite platforms working at C band to understand the dynamic of the whole volcano has been also investigated. Different images acquired from the ERS2, RADARSAT and ENVISAT satellites before and after the 2003 collapse of the landslide, and before and after the 2007 event, have been interferometrically processed as well. Notwithstanding the restricted number of available images, the ground deformation occurred on the island due to the volcanic activity has been obtained with spatial and temporal characteristics complementary to those ones provided by GB-InSAR.