On May 3 at 17:51 and 22:14, Florentines felt the first tremors in this latest spate of seismic activity. And just when we thought the fault had settled around Impruneta, a town 15 kilometres due south of Florence, another 3.7 flutter set our walls shaking on May 12 at 23:12. But just how great is the earthquake risk in Tuscany?
To date, the seismic activity in Chianti near Florence hasn’t resulted in any damage to persons or property, but it is nevertheless causing concern among those who live near the epicentre. After the tremor on May 12, the single emergency number 112 received approximately 350 calls from citizens expressing their worry at the event.
“Reassuring residents is not an easy task for administrations as the unknown quantity, i.e. how the earth movements could evolve, is far from resolved,” commented Riccardo Martelli, president of Tuscany’s professional association of geologists. “All we can do is trust the data that we currently have, which tell us that phenomena such as this recent seismic activity can occur locally. While recently they have not caused damage, in the past, higher magnitudes caused some buildings to collapse and even resulted in loss of life around Grassina and Lappeggi.”
Indeed, this isn’t the first time that the Chianti area has experienced seismic activity. A similar “swarm” occurred in December 2014 and January 2015, with a peak of 4.1 on the Richter scale on December 19 at 11:36. As Francesco Grigoli, seismologist at the University of Pisa explained in an interview to Corriere della Sera, “earthquake swarms lack a ‘main tremor’ and can last for several weeks before slowly dissipating… only in fewer than ten per cent of cases is the swarm followed (or can set off) an earthquake of a higher magnitude, which is what occurred with the 6.1 quake in L’Aquila in 2009.”
For the sake of historical truth, we should remember that the Mugello lies to the north of Florence, a seismic area that gave rise to two sizeable earthquakes, one measuring 5.5 in 1895 and another more destructive event just after 5pm on June 29, 1919 at 6.4.
“The epicentre was in Vicchio, which saw many houses destroyed and resulted in many injuries and approximately 40 deaths… In nearby villages, almost all the low-built houses, where fortunately only a few people live, were completely razed to the ground.”
Corriere della Sera, July 1, 1919
So, how should we (and the authorities) react to the current earthquake swarm near Florence?
To date, the seismic activity in Chianti near Florence hasn’t resulted in any damage to persons or property, but it is nevertheless causing concern among those who live near the epicentre.
More can be done to improve the antiseismic standard of Italy’s buildings, since recent earthquake proofing has tended to focus on isolated interventions as opposed to scheduled adjustments. Martelli continues: “In 2020, Tuscany’s professional association of geologists pushed the Italian Senate for an amendment to the Sismabonus legislation in order to introduce the possibility of financing the seismic vulnerability analysis of buildings. This measure would allow planned activities to secure buildings over the next few years as most of the edifices around us are not in line with the current legislation. That’s what we call prevention when faced with a phenomenon that continues to make us vulnerable.”
Mayor Nardella’s administration has called for similar measures given the recent spasm of more than 210 tremors in ten days. “Since 2016, we have conducted a static and seismic analysis of the city’s schools to the tune of approximately 500,000 euro and we’ve spent 19 million bringing 21 schools up to code. This summer, we have also planned another 25 anti-seismic improvements on our schools, worth eight million euro.” In his latest Facebook post, the first citizen also reassures that Fiorentina’s football stadium, the Mandela Arena events arena, and the Costoli and Bellariva have all passed seismic stability testing, in addition to checks of the city’s subsoil to understand how earth movements could potentially affect the built areas. However, a recent article in Corriere della Sera pointed out that seismic assessment of buildings is a lengthy process, which means that checks of certain edifices like Palazzo Vecchio are ongoing.
Out of an abundance of caution, the authorities have published advice on what to do before, during and after an earthquake. We also recommend checking out the Io Non Rischio website.
Florence city council has also signposted the 21 “safe” waiting areas in the event of an earthquake: piazzale Michelangelo, piazza d’Azeglio, piazza Santissima Annunziata, piazza Libertà, piazza Isolotto, piazza Pitti, piazza Tasso, piazza Bartali, piazza Pier Vettori, piazza Leopoldo; the car parks by the Costoli pool, in Trespiano, via Senese, viale Nenni Ipercoop, Meyer and via Palazzeschi; the gardens by Esselunga Le Romite, via dei Bassi, via Sardegna, and the via Perfetti Ricasoli playground; Careggi.