The seismographs of the INGV network detected a tremor associated with the violent explosion in the ENI depot in Calenzano, in the province of Florence, in December 9th. The accident has caused so far 4 victims, 26 injured and 1 missing. According to initial reconstructions, the accident occurred in a loading shelter due to a cloud of vapours caught fire while filling one of the tankers near a fuel storage tower. Investigations are underway to ascertain the dynamics of the disaster and the Prato prosecutor’s office has opened criminal proceedings to ascertain any responsibilities. Also noteworthy is the activation of IT-Alert to warn the population within a 5 km radius of the industrial site.
The population initially felt a strong roarsuch as to break glass windows throughout the area. The Fire Brigade only managed to put out the flames around 12pm yesterday, while a column of black smoke (due to the incomplete combustion of the hydrocarbons) could be seen even kilometers away. Do you think that the explosion was so violent that not only did windows break in the entire area, but the shock generated was also detected by the monitoring network of theNational Institute of Geophysics and Volcanologyespecially from the stations Montemurlo (MPPT, in light blue in the image below) a 13km from the industrial site e Carmignano (CRMI, in orange) a 15km.
In both cases two variations in the signal are distinctly seen:
- at 9:22:00 UTC (therefore 10:22:00 Italian) the P wavesthe first to arrive during an earthquake and produced by the explosion at the industrial plant. They are waves faster and type compressive;
- at 9.22.35 (10.22.35 Italian time) a second series of waves arrives linked to the acoustic wave of the roar.
Attention: it is fair to point out that the magnitude of the shock is still rather small and equal to 0.9, therefore a value low enough to be felt only at an instrumental level.
