Il earthquake that hit Catania following the last one eruption of Etna it has made a chronic problem of Italy, that of the earth shaking, once again topical. In which areas of the country do you run the most serious dangers? The same effect caused yesterday's earthquake in Avezzano. To try to clarify this issue, we re-propose the seismic risk map in Italy created by the National Institute of Geophysics and Volcanology.
Experts have identified four areas in the country:
– Zone 1 – It is the most dangerous, where very strong earthquakes can occur.
– Zone 2 – Strong earthquakes can occur in this area.
– Zone 3 – Earthquakes can be strong, but aftershocks are rare.
– Zone 4 – It is the least dangerous area, with low seismic incidence.
Here is the image elaborated by Ingv:
At a technical level, the seismic hazard map created by Ingv is based on the prediction of the maximum acceleration of the ground after the passage of seismic waves (S) in homogeneous rigid soils, within a depth of 30 metres.
For the original map, with all numerical references, refer to Ingv site.
In detail, the towns near Catania most affected by the last earthquake were Zafferana Etnea (with the hamlet of Fleri), Acireale (with the hamlet of Pennisi), Aci Sant'Antonio, Aci Catena, Aci Bonaccorsi and Santa Venerina. The earthquake was also felt in Taormina, in the Syracuse area and in the Ragusa area.
Among the tremors of December 26, the strongest, the one that arrived at 3.19 in the night, recorded a magnitude of 4.8 and a hypocenter just 1,2 km deep. There were several material damages, but luckily no casualties. 10 people were injured, all slightly.
According to Ingv surveys, the earthquake had its hypocenter just 1 km deep and its epicenter near the towns of Viagrande and Trecastagni.
Etna has recorded a further surge in the values of the tremors of its internal magma ducts, a sign of the presence of great 'energy' and moving magma that pushes against the walls of the volcanic edifice.
