On March 2, 1970, following the tremors caused by the phenomenon of Bradyseism, the authorities announced the first state of alarm and ordered the immediate evacuation of the Rione Terra.
The inhabitants of the heart of Pozzuoli were forced to leave their serious damaged or collapsed homes, and were transported to other areas, in the so-called public housing. In just two days the Rione Terra assumed the appearance of a ghost town. In a moment, the citizens were ripped away from the walls where they had built an entire life and that used to call home. Far from their affections and their everyday life, they had to build a new life.
The Rione Terra passed in a flash from a popular neighbourhood to the ground of no one, suffering years of complete abandonment, raped by the jackals who disfigured the memory with continuous looting and acts of vandalism. The works of art were lost and what remained in the rubble was taken away.
Bradyseism: a volcanic phenomenon
The term Bradyseism indicates a particular natural event related to volcanic activity in a specific area. This phenomenon is characterized by a gradual variation of the soil level (about 1 cm per year) which can be defined in two ways: negative (or descending) if it involves a lowering of the soil, or positive (or ascending) if, instead, it involves an elevation of the soil. The effect of bradyseism is evident along the seashore, through the progressive emergence or submersion of buildings, coasts and territories.
The Phlegraean Bradyseism
The phenomenon of bradyseism often occurs and especially in the area of the Phlegraean Fields, particularly in the Gulf of Pozzuoli.
In the area between Capo Miseno and Baiae up to Posillipo, the movements of bradyseism are repeated cyclically. There were three phases in the historical evolution of Phlegraean bradyseism: a first descending phase (from the 2nd century B.C. to the 9th century B.C.), followed by an ascending phase (from the 10th to the 16th century B.C.) and finally a third phase, the last, which still had descending character (from the 17th century until 1970).
Between 1970 and 1972, the phenomenon of Phlegraean bradyseism was reversed. From negative it has turned into positive leading to an overall uplift of about 160 cm. In the port of Pozzuoli, where the effects are more evident, the elevation was at least 90 cm, while the coast was up 20 cm.
The beaches widened, the piers and the docks rose up, and the connection that existed between the famous Temple of Serapis and the sea, QUI turned out practically useless.
At the same time there was an intense activity of the volcano Solfatara with fumaroles and puffs of smoke more extensive and intense.
The area of the Rione Terra was evacuated due to an excessive increase in damage and the inhabitants of the area were transported to the areas of Miliscola, Licola, Qualiano, Camaldoli and finally the district of Toiano.
The Paroxysm phenomenon
Bradyseism is characterized by moments in which the phenomenon intensifies taking the name of Paroxysm. The most important one happened in 1538 when a mountain was suddenly born on the coast of Pozzuoli: Monte Nuovo.
In the period between 1983 and 1984 the phenomenon assumed a rhythm of 3 mm per day causing an overall raising of 180 cm, in the area there were numerous earthquakes (up to 500 per day) of varying intensity with epicenter, between the center of Pozzuoli and Quarto.
All this was caused by a magmatic intrusion that alerted the whole community, in fact on August 24 of the same year, an emergency plan was implemented.
On September 5, 1983, Pozzuoli was struck by a fifth degree earthquake that was felt in all the Phlegrean coast, in the inland areas, up to Quarto and Pianura, Posillipo, and Vomero.
Curiosities about the Phlegraean Bradyseism
The English naturalist Charles Lyell, who visited the Phlegraean area, was incredibly impressed by the evidence of variations in sea level found on the columns of the temple of Pozzuoli. He considered this case as such a striking example that he used the image of the columns of the temple as a figure on the title page of his book Principles of Geology, published in 1832 and which is considered the first modern book of geology.
Historical measurements and in modern times
In the past the phenomenon of bradyseism in Pozzuoli was measured with special instruments: the columns of the Temple of Serapis (the ancient Macellum) in Pozzuoli, that until 1983 were partially submerged by the sea. Today, on the other hand, they stand above sea level and have characteristic holes dug by molluscs (Lithophaga lithophaga commonly called date shell or date mussel) up to a height of 6.30 m.
This attests without a doubt that it was the maximum bradyseism submersion suffered by the Phlegraean Fields in medieval times, however it is good not to be fooled: the water present today in the Temple of Serapis is due to a thermal spring below (called Cantarello) and to meteoric precipitation.
In modern times, however, it is possible to obtain extremely precise measurements through satellite surveys. These satellites calculate the data compared to fixed points (in the form of coated metal pyramids), located in the various affected areas throughout the Gulf of Pozzuoli. The most recent surveys made with GPS by NIGV showed a tendency to raising that had an acceleration from June to August 2012 and from the beginning of December 2012, with a total raising from January 2012 of about 9.5 cm.
Possible causes of Bradyseism
The bradyseism causes are not yet clear. An old theory looked for the causes in magmatic waves that, as they passed, would lead to the characteristic variation of the level of the Earth’s crust where it was thinner.
More recently, instead, it was argued that the phenomenon was due to changes in the volume of a magma chamber near the surface, however a rise of magma either solidifies, or leads to a volcanic eruption, never descending again to the starting level, so this theory is not acceptable.
Currently, variations in the temperature of the groundwater are identified as the cause of bradyseism: increases or decreases in temperature would cause greater or lower pressure of water vapor in the subsoil with consequent deformations of the surface crust.
Bradyseism in the rest of the world
In 2010, in Rabaul within four months preceeding a major eruption, bradyseism caused a rise of the caldera of about 4 cm.
In Sierra Nevada, on the other hand, the caldera of the Long Valley in California, has suffered a rise of the earth’s crust of about 80 cm between 1979 and 2000 as a result of underground volcanic activity. This increase is related to the terminal phase of magma chamber activity.
The rebirth project of the Rione Terra
In January 1992, the Campania Region began the first restoration works of the Rione Terra, that were however opposed and slowed down by the continuous arrests due also and above all to the mismanagement of the area.
Despite, to date, most of the buildings have been renovated, the Rione Terra is still crossed by cranes and workers that make it a curious tourist attraction. The only building frequented is the Palazzo Migliaresi, that houses the seat of the Municipality of Pozzuoli, opened in 2016. The visitors, attracted by its history and its sad vicissitudes, walk around curious to observe this strange open yard overlooking the sea.
By 2022 Rione Terra will become, according to the project of the Municipality of Pozzuoli, a tourist site with hotels and luxury residences. To date, with the project of Puteoli Sacra the Rione Terra is coming back to life. The Duomo Temple was reopened to tourists, better known as the Cathedral of Saint Procolus Martyr, the Museum and the Diocesan hypogea.
Puteoli Sacra, a project of historical and personal rebirth
Twenty-four young people at risk of social exclusion, coming from the penal area, will be the direct protagonists of the rebirth of the Rione Terra as a tourist site. A project of social integration and enhancement of cultural sites.