If there is a place in the world where the breath of the Earth can be seen and heard and even smelled, this is the crater of the Campi Flegrei where the perennial boiling of the volcanic activity of the subsoil has always erupted fumaroles on the surface and caused earthquakes, generally of low magnitude. magnitude, which are frightening today.
Last night the operations room of the INGV Vesuvian Observatory calculated around 150 tremors in 6 hours at a depth of 3 kilometres, and the strongest of the last 40 years, of magnitude 4.4, was also felt at 8.10pm in Naples. In Pozzuoli and Bagnoli the Civil Protection set up tent cities for the 35 families displaced from buildings at risk and for those who did not return home, and many spent the night in the car.
But the shocks are a constant. In 2023 alone there were over 5,000 tremors indicating changes in sea level in the Gulf of Pozzuoli and ground lifting indicated as “slightly accelerating”.
On the entire planet, the Campi Flegrei have only one “twin”, only one area with similar characteristics, and it is the super-volcano area of the Yellowstone national park, with two vast magma chambers, nothing to do with the 19 active craters on the outskirts of Naples concentrated in less than 100 square km in the caldera with an almost circular shape, with a radius of about 4 km from Pozzuoli. However, two huge differences make the underground panorama just west of Naples unique and much more risky.
The first difference is the presence of Vesuvius, the active volcano overlooking the area, and the volcanism present under the island of Ischia right in front of Pozzuoli. The second difference is a fact of reality: if the two Yellowstone calderas under Montana, Idaho and Wyoming exploded, they would only cause damage by modifying the wild lands of the West with the immense uncontaminated landscapes of the National Park which covers approximately 9,000 square km in top of the volcanic formation, with its breathtaking canyons, large rivers, immense lush forests, many hot springs and active geysers with the famous Old Faithful, and obviously on the hundreds of animal species, including bears, wolves, bison, elk and antelope.
But it would not affect humans, infrastructure and buildings.
On the contrary, the Phlegraean area is densely inhabited by around 550,000 people, has been hyper-urbanized in defiance of both natural laws and those of the State, and plastically represents that dose of Italian fatalism supported by an illegal building system unique in the world which made it possible, in total ignorance of the minimum prevention criteria and scientific warnings, to create conditions of great risk precisely on the surfaces of the active craters “plugged” by anthills of buildings, shopping centers and infrastructures.
In short, the caldera is under the homes and under the feet of those who live in this mythological area, unique in the world and the most monitored in the world by the Vesuvian Observatory and the National Institute of Geophysics and Volcanology, with some of the most advanced monitoring networks, with satellite systems and ultra-sophisticated sensors that detect in real time physical-chemical parameters and every variation in temperature and gas emission between Solfatara, Pisciarelli and Agnano and in the Gulf of Pozzuoli.
What history tells us about our “Kingdom of Fire” is that the two major eruptions date back to 39,000 and 15,000 years ago. Since then, 3 periods of intense eruptive activity have alternated with centuries or millennia of rest, with the last one ending 3780 years ago. But on 29 September 1538, a minor eruption interrupted 300 years of quiescence, forming with the eruptions, between the end of September and the beginning of October, the cone of Monte Nuovo, the youngest volcanic apparatus in Europe, not far from the caldera of Lake Averno which boils today and whose ancient name indicates, not by chance, an area “without birds” due to the gases released, and it is still no coincidence that the lake was feared and narrated as the“Entrance to the Underworld”.
However, the Campi Flegrei have become one of the landscapes of fragile Italy, in this case volcanic, undervalued, underestimated and removed. They should teach us forgetful Italians that on our peninsula we have several volcanic systems, fortunately for us extinct for over 10,000 years, such as Amiata, Vulsini, Cimini, Vico, Sabatini, Pontine Islands, Roccamonfina, Vulture.
But we also have volcanoes in a long phase of rest such as Colli Albani, Ischia, Vesuvius, Salina, Lipari, Vulcano, Pantelleria, the Ferdinandea island under the Sicilian sea, the Marsili which in the depths between the Gulf of Naples and the Aeolian Islands is the largest of the continent, and the Campi Flegrei falls into this category. And that 2 volcanoes such as Stromboli and Etna are always active. Italian volcanism has been a history of eruptions for two thousand years, thanks to the writings of Pliny the Elder, the scholarly encyclopedic who died in the eruption of Pompeii, a fascinated scholar of that event, to Geography by Strabo who already detailed the expelled products and the eruptive phases and the dangers, reporting news of eruptions including submarine ones.
The earth “that burns” of the Flegrei was mythologized by pre-Roman peoples as the area inhabited by terrifying snakes and dragons, then by the conquering Greeks and the Romans with the presence of the god of fire Vulcan or Hephaestus. Legends and interpretations have transformed it into the magical-sacral crossroads of Volcanoes or Burning Fields Forum, passed down as the location of furious battles between gods. One of these was fought by Atlas, brother of Prometheus and Menoetius, allies of the Titans and Cronus, against the gods of Olympus, and Zeus struck down Menoetius with a thunderbolt, locking him up under the caldera, and condemning Atlas to carry the sky on his his shoulders. Another narrates the assault on the sky of the gods attempted by the 24 Giants, another fantastic battle that seems like a cinematic blockbuster, which Homer placed in the Phlegraean Fields with Zeus still victorious who imprisoned them all under the calderas.
A stone’s throw from here was the cave of the Cumaean Sibyl, the mother of all Italian prophetesses, the priestess of Apollo of the Romans. It was the time when the area was the kingdom of the thermal waters of Campania Felix, much exploited with the “Nero’s stoves”, the monumental thermal baths between Pozzuoli, Agnano and Lucrino with the smoking craters next to them. Paradise places between Miseno the most important military Portus Julius of the Imperium, Nuceria, Stabia, Oplontis current Torre Annunziata, Herculaneum which took the name of the demigod hero Hercules, Pompeii, Neapolis and Baia capital ofOtium of the Roman aristocracy. Everything lasted until the eruption of Vesuvius, ours Ground Zero which imprinted the date of August 24, 79 forever in the history of humanity.
Today in Pozzuoli you can still admire the phenomenon of bradyseism, which between Capo Miseno, Baia and Posillipo causes the ground to lower and rise by approximately one centimeter per year. It rises and falls on the push of magmatic gases and subsurface fluids that rise inside the magma chamber at about 4 kilometers deep.
The Roman temple of Serapis, brought to light in August 1952, is a measure of telluric changes in the soil. It was once located right in the center of the Pozzuoli market dedicated to Serapis, and on the columns of the Serapeum the variations in the water are indicated, even notable in different periods of crisis.
The market and port of Pozzuoli, in fact, were below sea level for long periods, and since 1950 there have been even rapid uplifts such as from 1969 to 1972 for 1.70 meters or from 1982 to 1984 for 1.87 meters when 40,000 people were evacuated due to the over ten thousand small tremors and the 2 meter swelling.
From 1984 the descent of about 93 centimeters began until 2006 and, since then, new slow but continuous rises have been recorded. Today the ground level is 13 centimeters higher than in 1984, and rising by 15 millimeters per month. As it rises, it accumulates stresses which are discharged onto the rocks which release energy and when they end up fracturing, they generate small earthquakes.
What awaits us? As Mauro Antonio Di Vito, leading expert on the caldera and director of the Vesuvian Observatory of the National Institute of Geophysics and Volcanology, always reminds us, the cause of the uplift is the strong rise of fluids concentrated in the Solfatara-Pisciarelli area, linked to the push towards the upper one generated by fluids or magmatic melts that are generated at depths between 6-8 km below the Campi Flegrei. The volcanic eruption, for INGV, remains a relatively low hypothesis. As long as the caldera rises, seismicity will be able to manifest itself both with stronger events and with swarms. But the real issue for the immediate future is understanding whether the crust fractures. It is not possible to make predictions at the moment.
Science monitors the caldera to the millimetre, and the Civil Protection led by Fabrizio Curcio has been on zero-alert alert for some time. He must manage the infinite problems of the possible phases of the “during” he was born in “After” a possible crisis. The preventive evacuation plans must be able to set in motion an unprecedented emergency machine, both in the most exposed areas of the 7 Municipalities of the red zone – Pozzuoli, Bacoli, Monte di Procida, Quarto and part of Giugliano, Marano and Naples -, both in the areas of yellow area. Twinning will have to work with the rest of Italy which will have to welcome displaced families: Pozzuoli in Lombardy, Bacoli in Umbria and Marche, Monte di Procida in Abruzzo and Molise. With unknowns especially on the escape routes, the only possible defense measure.
Time will be everything. The overall estimated time to move away from the red zone, once the alarm has been triggered, will be 72 hours. The roads will have to be cleared and 6 confluence areas ready for “assisted transport”: Naples central station and maritime station at the port; Afragola, railway station, Giugliano, Don Diana institute, Aversa railway station, Villa Literno railway station. This presupposes perfect coordination and all the deadlines to be respected, the dissemination of the plan as widely as possible, training and preparation and the knowledge to know what to do and how to react.
Very old problems. In the “Naturales Questiones”, Lucio Anneo Seneca posed this problem as the main one for his contemporaries: “Since the cause of our fear is ignorance, isn’t it worth knowing so that we no longer fear? How much better it is to dedicate yourself completely to this with all of yourself! And no more worthy topic could be found…”.
