An adventure that begins in the seventeenth-century Basilica of Santa Maria Maggiore della Pietrasanta, in the heart of Naples, and continues into the bowels of the city following a path that takes the visitor on a journey through the geological history of the Neapolitan territory. This and much more in the exhibition Naples – History, Art, Volcanoes curated by the Vesuvius Observatory of the National Institute of Geophysics and Volcanology (INGV-OV). To find out the details, we interviewed the INGV volcanologist Mauro Antonio Di Vito who, through his story, leads us into the fascinating world of the Neapolitan subsoil.
What proposals did you come up with for the exhibition? What can you see and which audience are you targeting?
The museum set up in the Basilica of Santa Maria Maggiore della Pietrasanta is an exhibition of the cultural, historical and volcanological stratigraphy of the city of Naples. At the beginning of the itinerary, 15 Gouaches from the 15.000th and 25th centuries from the Vesuvius Observatory collection are on display. Subject of the paintings, the eruptions of Vesuvius in past centuries, when it was in a state of semi-persistent activity, with spectacular eruptions. These works represent precious documents, as they faithfully show what the volcano was like in the past, the position of the eruptive vents, the height that the lava fountains reached and where the flows flowed. Continuing, the visitor will come across a mega screen which displays, thanks to a system replicating the one present in the OV Surveillance Room, the epicenters of the earthquakes in the Neapolitan volcanic areas. Although in the popular imagination when one thinks of the volcano the thought turns to Vesuvius, there are two other active volcanoes in the area: Campi Flegrei and Ischia. It is precisely through this screen that the signals of the "breath" of the three volcanoes can be observed. Continuing the route it is possible to observe the stratigraphic sequence of the products of the prehistoric eruptions of Vesuvius and Campi Flegrei, up to an enormous cavity excavated in the Neapolitan yellow tuff. This material is the product of an eruptive activity dating back to XNUMX years ago which constitutes the backbone of the Neapolitan capital, below which many underground cavities have been excavated which characterize the subsoil of the city. A synthetic but rigorous film on the eruption that produced this famous rock is projected onto a wall of Neapolitan yellow tuff. Obviously this is a fantastic reconstruction, based however on scientific data. The descent continues and soon a new route will start, about XNUMX meters deep, dug into the tuff. Here it will be possible to observe beautiful buildings: cisterns, aqueducts from the Roman era, stairs carved into the tuff and much more. Here you can also see the marks left by man since he began to build these cavities, some of which date back to the Greek era. In the cavity there are also traces of use during the last war, when these places were shelters during the bombings. This is only part of the exhibition, which is aimed at the whole family. I'll tell you an amusing detail: the "story" is told by an "imaginary" character, Pietro, a volcanologist who explains the characteristics of the rocks and the dynamics of the eruptions to his friend Strella, an erudite bat who lives in underground cavities. A playful way to rigorously represent the peculiarities of the route. Furthermore, the story was illustrated by the Italian School of Comix and will be distributed shortly.
Are there other access points in the city of Naples where it is possible to see the stratifications produced by the eruptions?
The tuff extraction operations largely involved the subsoil of the city and there are many buildings that have underground cavities, often used as cisterns or cellars as they are characterized by high humidity and constant temperatures. An access point, not very deep but particularly significant, is within Castelnuovo (Maschio Angioino), where it is possible to observe the stratification of the last 7.000 – 8.000 years of eruptions, both of Vesuvius and Campi Flegrei. Then there are the excavations of San Lorenzo, the Bourbon Tunnel, very beautiful and very complex, and many other cavities. What differentiates the itinerary of the Naples – History, Art, Volcanoes exhibition, however, is the scientific treatment of what it is possible to see, it is its uniqueness.
Returning to the itinerary of the exhibition, what are the eruptions that have left the most evident signs?
They are two in particular. The first is that of Agnano Monte Spina, a Plinian eruption that took place in the Campi Flegrei about 4.500 years ago. The event affected an area already inhabited in the Neolithic by many communities who devoted themselves to agriculture and pastoralism: the products of the eruptions buried the signs of these activities, including traces of cultivation, villages, fences and actual roads .
Then there is the Plinian eruption of the Pomici di Avellino, which took place at Vesuvius in the Early Bronze Age, about 4.000 years ago. This was also a major impact event that covered thousands of square kilometers with its deposits. At that time the area around Vesuvius was widely used and the deposition of the ashes from the eruption has preserved numerous traces of the presence of the communities that lived in a very fertile area. The study of the eruption deposits has also allowed us to detect the presence of traces of an extensive migration, during the eruption, of the populations that survived the eruption, who migrated with their flocks and herds towards the North.
What is the relationship that binds the population of Campania to its volcanoes today?
I have always found a very deep relationship with "the volcano" in Vesuvius and also in Neapolitans, used to seeing Vesuvius. It is a very suggestive volcanic edifice, covered in vegetation in spring and snow in winter, which unfortunately has given many problems in the past. It is not only the most evident volcano, it is also the one that produced the last eruption, a medium-low scale event which dates back to 1944. A strong relationship is also that of the population with Campi Flegrei and Ischia, but in a different way. This is because in the collective memory there are no memories of the last eruptive events which in the Campi Flegrei date back to 1538, while Ischia saw its last eruption in 1302. In the Campi Flegrei, however, other phenomena are well known to the population such as the deformation of the soil and seismicity. Furthermore, the awareness of living with active volcanoes is increasing more and more, also thanks to the information that is periodically provided by INGV precisely on the state of activity of these volcanoes and on the potential risks associated with eruptions.