AStrombolian eruptive and effusive activity at the New Southeast Crater, taken from Zafferana Etnea (April 24, 2012). On the right, the bell tower of the mother church of Santa Maria della Provvidenza (photo by Marco Neri). In the Spring of 2012, the eruptive episodes of an explosive-Strombolian nature, even violent, produced by Etna were numerous .
During situations of crisis or volcanic emergency, the activities carried out by the Institute, and in particular those of the volcanological observatories, intensify. The increase in activities and personnel involved depends on the level of activity observed or expected at the volcano and follows the procedures and protocols in place at the Observatories and provided for by the agreements in force with the National Civil Protection Department (DPC) and other authorities of regional and territorial civil protection.
In these particular periods, the activities focus on the organization and implementation of interventions to enhance the permanent monitoring and observation systems through the deployment of mobile stations (eg seismic, geodetic and/or multi-parameter stations with the integration of microphones infrasonic and radiometers), possibly also in collaboration with the operational groups foreseen in the event of a seismic emergency. The analysis and interpretation of instrumental data and campaign observations collected are enhanced, also for the purpose of preparing appropriate expected scenarios or hazard assessments. At the same time, communication and information activities towards the public are also being strengthened, both through the institutional web portal and through the various social channels. Finally, in particularly serious cases, specific Crisis Units are established with the aim of supporting and strengthening the action of the volcanological Observatory of competence through contributions from other Sections of the Institute or from other institutions.
The data and observations collected by the monitoring networks, together with the hazard assessments elaborated by INGV are promptly transmitted, according to agreed procedures, to the DPC, the regional civil protection structures, the competent Prefectures and any other Competence Centers involved.
Based on this information, the Civil Protection Department defines the alert level to be assigned to the volcano. The warning system that the DPC has set up, in collaboration with INGV itself and with other Centers of Expertise, qualitatively expresses the state of activity of the volcano and its possible evolution, contemplating plausible scenarios and their relevance, on a scale local or national.
The general scheme shown below describes the levels of alert foreseen, according to the progressive removal of the volcanic system from an equilibrium condition, which ideally does not involve danger. However, it should be kept in mind that some volcanic phenomena are completely unpredictable and that therefore, even with the Green alert level, the risk should never be considered null. For more information, see the following link of the Civil Protection Department: