Spent about 6 month in Naples and visited Camp Flegrei several times. Given the population density of the area, an eruption could be . . . bad.
Almost 500 years ago, Italy's Campi Flegrei supervolcano erupted, spewing molten rock and thick plumes of smoke into the atmosphere for eight days straight, and literally forming a new mountain from the chunks of Earth it drew from below.
Now, researchers are warning that this vast, fiery cauldron could be ready to blow once more, with pressure building up over the past 67 years showing no signs of easing up. And just to put that into perspective, this supervolcano is responsible for one of the biggest eruptions on the planet.
"By studying how the ground is cracking and moving at Campi Flegrei, we think it may be approaching a critical stage where further unrest will increase the possibility of an eruption, and it's imperative that the authorities are prepared for this," says Christopher Kilburn from the University College London Hazard Centre.
You might picture a supervolcano as just like a regular volcano, only super-sized, but it's more like a giant volcano that's been flattened into the ground, leaving extensive fields of volcanic activity like we now see at Yellowstone.
Campi Flegrei (or "burning fields" in Italian) covers an area of 100 square kilometres (38 square miles) just west of Naples, with a massive 12-km-wide (7.4-mile) caldera at its centre. It boasts 24 craters and large volcanic edifices, mostly hidden under the Mediterranean Sea.
In recent times, Campi Flegrei has had two major eruptions - 35,000 years ago and 12,000 years ago - and a smaller eruption in 1538.
It's all relative though, because that "smaller" eruption lasted for eight days straight, and spewed so much material into the surrounding area, it formed a whole new mountain, Monte Nuovo.
Campi Flegrei (also referred to as Phlegrean Fields) is a volcano located in southern Italy, immediately north-west of the city of Naples. The structure is not that of a more classical stratovolcano (a more or less regular cone surmounted by a volcanic crater), instead that of a large, 12x15 km caldera, this being a vast depression originated by a structural collapse following one or more large-scale volcanic eruptions. The Campi Flegrei caldera has been largely filled by volcanic products from eruptions originated after the caldera formation, so that the general appearance to-date is that of a generally flat area punctuated by several post-caldera volcanic craters.
The last eruption occurred in 1538, and was among the smallest recorded in the eruptive history of Campi Flegrei. This eruption interrupted a period of quiescence of more than 3,000 years, and in about one week it originated the Monte Nuovo (= “New Mountain”) cone, about 130 m high. Since then, the activity at Phlegraean Fields has been mainly characterized by bradyseism (slow upward or downward motion of the caldera floor), and fumarolic activity mainly located in the Solfatara crater.
Since the 1950s the Campi Flegrei volcano is in a state of unrest, characterized by discrete (months to years) periods of caldera floor up-rise accompanied by seismic swarms and shortly followed by significant changes in the composition and flow of fumaroles. The latest crisis occurred in 1983, when about 40,000 people were evacuated from the town of Pozzuoli. During last ten years there have been several minor uplift phases, each accompanied by seismic swarms, and a general intensification of the fumarolic outflow that overall contribute to substantial concern for a possible reappraisal of the volcanic activity in the area.