Etna - Eruption 2008-2009
On May 13, 2008 on Etna begins a phase characterized by eruptive activity rather intense. A fracture opens at an altitude of 2800 m, at the eastern base of the northeast crater. This is a Strombolian volcanic activity with the emission of well-fed lava flows, which flow into the Valle del Bove.
Forerunner phenomena. The opening of the fracture is preceded by an intense seismic swarm that registers about 230 very superficial shocks in the Valle del Leone area, near the crater area. The strongest of these shocks is a magnitude of 3.9. The most energetic events are felt by the population of the towns of Milo, Randazzo and S.Alfio.
Activation of Cfc-rv and alert procedures. The initial phases of the eruptive episodes are accompanied by the formation of columns of ash, whose fallout affects the towns located on the north-eastern side of the volcano, until you reach the city of Milazzo. The Central Functional Centre for Volcanic Risk - Cfc-rv immediately contacts the heads of the monitoring centres for an initial evaluation of the phenomena in progress. At the same time, alert procedures are activated.
Acquisition of radar satellite images of the Cosmo-SkyMed constellation. On May 14, 2008, dense cloud cover made the use of surveillance cameras and traditional optical satellite sensors (AVHRR, MSG and MODIS) to identify the position of the eruptive fracture ineffective. The procedures for the near-real-time acquisition of high-resolution radar satellite images of the Cosmo-SkyMed constellation, developed within the framework of the projects of the Italian-Asian Space Agency, are then activated. The comparison with an image of the same area taken a few months before allows to identify with absolute precision the position of the eruptive fracture and the side affected by the subsequent effusive activity.
Procedures for the definition of hazard scenarios. Subsequently, procedures are tested for the definition of hazard scenarios resulting from the placement of lava flows through the use of the simulation model MAGFLOW, developed as part of the projects planned for the three-year period 2007-2009 between the Civil Protection Department and the National Institute of Geophysics and Volcanology-Ingv.
In July 2009, the eruptive activity to the fracture at the base of the southeast crater ends. The activity returns to focus on the summit crater mouths.