The Umbria and Marche earthquake of 1997 affected part of the two regions in Central Italy in September-October 1997 and in March 1998.
The Umbria and Marche earthquake of 1997
On 26 September 1997, two seismic events of magnitude 5.7 and 6.0 struck the Colfiorito area (on the Umbria and Marche border) nine hours from each other (at 2:33 a.m. and 11:40 a.m. Italian time). The earthquake had a maximum intensity of IV on the Mercalli Scale.
The 1997 seismic sequence on the border between Umbria and Marche represented a watershed for Italian seismology. It was the first earthquake for which high-quality data were collected from ground monitoring networks and from satellites. The picture that these data provided allowed for outlining with a precision never achieved before the characteristics of the faults involved and the mechanisms that generated the Apennine earthquakes. The seismic events of the following years, those of L’Aquila in 2009 and the recent Amatrice-Norcia-Visso sequence of 2016–2017, demonstrated many of the interpretations taken from the 1997 earthquake studies, highlighting further characteristic elements. The photo gallery shows some images of the Mobile Seismic Network of the NIG (National Institute of Geophysics, later merged into the National Institute of Geophysics and Volcanology), installed in the early hours after the earthquakes of 26 September, which represented one of the most important tools for seismological research, as well as a very important information reference point for the local community affected by the earthquake in 1997.
The Shocks of 26 September 1997
On 26 September, at 2:33 a.m., there was an earthquake with intensity of VIII-IX on the Mercalli Scale, or magnitude 5.7, with epicentre in Cesi. Many houses were severely damaged by the earthquake, especially those in the municipalities of Foligno and Nocera Umbra, where about 85% of the buildings were unusable. In the morning many schools were closed, either as a precaution or because they were inaccessible. Many churches, including the Basilica of St. Francis in Assisi, suffered serious damage.
That same day, at 11:40:26, an earthquake of magnitude 6.0 and intensity IX on the Mercalli Scale, with a depth of 9.8 km and epicentre in Annifo, once again shook many towns between Umbria and Marche. This was the biggest event on record. After the two victims in the morning, eight more victims were added.
Subsequent shocks
On 14 October 1997, at 5:25 p.m., a distinct earthquake, with epicentre between Sellano and Preci, struck the earthquake zones again with a magnitude of 5.6, worsening the already very bad situation the homes were in.
After a period of continuous minor shocks, on 26 March 1998 a tremor was recorded, this time with epicentre in Gualdo Tadino, with a magnitude of 5.4. Given the great depth of the hypocentre, 45 km away, the earthquake was felt in many Italian cities. On the other hand, the depth attenuated the earthquake’s power in the areas adjacent to the epicentre, limiting the damage. The most intense tremors ended between 3 and 5 April, with magnitude 5.1 and 4.7.
On 1st November 1997, thanks to a collaboration between the army and the municipality, the first website in the world of a national civil protection emergency, www.terremoto.org, was tested at the MOC (Mixed Operational Centre) of the municipality of Foligno. Surpassing fax technology, the website made it possible for the data of temporary accommodation centres to be communicated in real time for the first time, and delegations from all over the world were able to appreciate the new emergency management tool provided by the Internet.
Damage and victims of the 1997 earthquake
The municipalities most affected by the earthquake were Foligno, Nocera Umbra, Preci, Sellano, Assisi and Spello in Umbria, as well as Fabriano, Serravalle di Chienti and Camerino in Marche.
The overnight shock of 26 September seriously damaged the buildings of Apennine towns. The one in the morning caused the collapse of some buildings or parts of them, already damaged by the previous shocks, including Giotto’s vault at the upper Basilica of St Francis in Assisi.
Damage was also reported in Marche, and in the areas closest to the border with Umbria and therefore closer to the epicentre. Many buildings showed conspicuous cracks, there were damaged roadways, and some structures were declared unusable. Significant damage was also recorded in Visso, Fabriano, Matelica, Pioraco and Fiuminata.
Four people were killed in the collapse in Assisi, including two technicians and two friars, who were checking the damage. The images of this collapse were shot by Umbria TV cameraman, Paolo Antolini, who was inside the basilica at the time along with journalist, Sofia Coletti. During the collapse, the two reporters remained unscathed and their footage were shown all around the world. The final toll was 11 dead, nearly 100 injured and at least 80,000 displaced.
There is another emblematic footage of the earthquake of 14 October 1997 showing the collapse of the lantern of Foligno City Hall, seriously damaged by previous earthquakes. Overall, the Umbria – Marche earthquake directly or indirectly caused the death of eleven people and extensive damage to monuments and works of art.
Restoration and reconstruction works
For restoration of just the vault of the Assisi basilica, the sum of approximately €35 million was needed. For the relief and aid of nearly 33,000 people, roughly €8 billion in expenditure were foreseen.
Years later, many inhabitants of the earthquake zones were still living in wooden houses.
According to data from the Umbria Region Reconstruction Observatory, as of December 2014, 97% of the population affected had returned to the houses damaged by the earthquake, with an expenditure of €5.106 billion.
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