Are you prepared? Volcanic risk at the Phlegrean Fields

Phlegraean Fields are an active volcano

The Phlegraean Fields is a vast active volcanic area with a structure called a "caldera," that is, a lowered area with an almost circular shape that was formed by large explosive eruptions. The caldera of the Phlegraean Fields extends from Monte di Procida to Posillipo and also includes an underwater part in the Gulf of Pozzuoli. Within the caldera, more than 70 eruptions have occurred over the past 15,000 years, forming volcanic buildings, craters and volcanic lakes that are still visible, such as Astroni, Solfatara and Lake Averno. The last eruption, in 1538, was preceded by a ground uplift that reached 19 meters in two years and gave rise to the volcano Monte Nuovo. Since then, the caldera has been quiescent, "dormant," but now shows signs of activity such as seismicity, fumaroles, and ground deformation.

In particular, the Phlegraean Fields are characterized by the phenomenon of bradyseism, that is a slow lifting and lowering of the soil. The last bradyseismic crises occurred in 1969-1972 and 1982-1984 with a considerable lifting of the ground and hundreds of earthquakes that led to the removal of the population of the Rione Terra di Pozzuoli.

Since 2006 the soil lifting reached a new phase and in 16 years rose by one meter causing many earthquakes.

Since 2012, the variations of some parameters monitored by th NGV Vesuvius observatory (seismicity,changes in the geochemical composition of the Fumarola ans soil gas and soil uplift) led to the need to raise the alert to the yellow level and the activation of the operational phase of attention.

What could happen in case of an eruption?
In the past, the volcanic activity of the Phlegraean Fields has been mainly characterized by explosive eruptions. This type of eruption, and the following phenomena, could also be expected in the future:

  • formation of an eruptive column of gases and shreds of incandescent lava, high up to tens of kilometres;
  • falling of large volcanic material in the area closest to the eruptive mouth, and also of ash and lapilli up to ten kilometers away, along the wind direction;
  • pyroclastic flows (avalanches of gas, ash and volcanic fragments) generated by the collapse of the eruptive column. These flows have high speeds and temperatures and can flow for several kilometres;
  • phreatic explosions, particular explosive phenomena that occur mainly in areas with intense hydrothermal activity, such as that of Solfatara/Pisciarelli;
  • flooding of depressed areas, due to abundant rainfall generated by the water steam released during the eruption and the accumulation of volcanic ash that makes the soil impermeable.

Can eruption in the Phlegraean Fields be expected?

Phlegraean Fields are among the most monitored volcanoes in the world because eruptions are often preceded by “precursor” phenomena (earthquakes, soil deformations, changes in composition and temperature of fumaroles, etc.).

The monitoring of these phenomena is fundamental to determine the state of activity of the volcano, the alert level, and also for the implementation of the measures provided for in the Civil Protection Plan. However, the present scientific knowledge does not allow to predict with certainty when, how and where the next eruption will occur, also because of the peculiarities of the caldera. Also, it is not possible to predict the duration of the eruption.

How does the warning work?

The alert system provides specific “alert levels” describing the state of activity of the volcano, based on the parameters of monitoring and any ongoing phenomena. The green alert level corresponds to the ordinary activity of the volcano while the yellow, orange and red alert levels represent increasing stages of unbalance of the volcano towards a possible eruption. The duration of each alert level can be extremely variable.

The alert levels are declared by the Department of Civil Protection, in conjunction with the regional civil protection. A possible change in level is assessed on the basis of the indications provided by the Vesuvian Observatory of the National Institute of Geophysics and Volcanology and the opinion of the National Commission for the Forecasting and Prevention of Major Risks.

Actions to be implemented by the National Civil Protection Service are defined in the operational phases (attention phase, pre-alarm and alarm) provided for in the civil protection plans. The President of the Council of Ministers declares the pre-alarm and the alarm phase.

What does the civil protection plan provide for?
For the red zone, the only preventive measure is to remove the population before the eruption begins. People can decide whether to find accommodation outside the risk zones or to benefit from accommodation offered by the State in the Autonomous Region or Province twinned with their Municipality.

For the yellow zone, the removal of the population will be assessed on the basis of the current event, the direction of the winds and the extent of the eruption.

The Plan for volcanic risk at the Phlegraean Fields is set at national level, therefore it must be drawn up by the entire National Service of Civil Protection starting from the Civil Protection Department, the Campania Region, the Prefecture of Naples, the Municipalities of the red zone, the Regions and twinned autonomous Provinces.

How do I know which areas are at risk?
The red zone encompasses the area exposed to pyroclastic flows which, due to their high temperatures and speed, represent the most dangerous phenomenon for people. The red zone includes the municipalities of Pozzuoli, Bacoli, Monte di Procida and Quarto; part of the municipalities of Giugliano in Campania and Marano in Naples; some districts of Naples: Soccavo, Pianura, Bagnoli, Fuorigrotta and part of the districts of San Ferdinando, Posillipo, Chiaia, Arenella, Vomero, Chiaiano and Montecalvario.

The yellow area includes the area exposed to the danger of lapilli and volcanic ash fallout. The yellow zone includes the municipalities of Villaricca, Calvizzano, Marano di Napoli, Mugnano di Napoli, Melito di Napoli, Casavatore and 24 districts of the Municipality of Naples: Arenella, Avvocata, Barra, Chiaia, Chiaiano, Mercato, Miano, Montecalvario, Pendino, Piscinola, Poggioreale, Porto, San Carlo all’Arena, San Ferdinando, San Giovanni a Teduccio, San Giuseppe, San Lorenzo, San Pietro a Patierno, Scampia, Secondigliano, Stella, Vicaria, Vomero and Zona Industriale.

In what consists the removal from the red zone?
In the pre-alarm phase, people wishing to leave the red zone can do it independently, moving to an alternative accommodation  (second home, to relatives or friends, rented house)part receiving a financial contribution from the State.

In the alarm phase, the population can decide whether to move by their own means, notifying their municipality, following the routes provided by the plan and according to the timetable established, or by means made available by the State. It is possible to decide whether to move to an alternative accommodation chosen independently, receiving a financial contribution from the State, or to benefit from the accommodation offered in the region or autonomous twinned province.

Those who decide to leave with the means made available by the State, are required to go to the waiting area identified by the Municipal Civil Protection Plan, either independently or with the shuttles organized by their municipality. From here, the transfer to the meeting area outside the red zone will take place with the buses of the Campania Region while the transfer to the Region or twinned Autonomous Province will be provided by the means of transport identified by the planning (train, bus, ship). Details regarding the transfer and reception to the population will be defined in the Plans of the individual Regions and Autonomous Provinces.

What do you need to know?

  • If you live, work or stay in the Phlegrean Fields territory, check if your area is in the red or yellow zone.
  • Eruptions can be preceded by earthquakes: keep in mind the rules of conduct on
  • Volcanic gases released by the caldera, in certain concentrations, can be very dangerous to human health and animals. Some of these gases are odorless, tasteless and colorless and therefore cannot be perceived.
  • The only safeguard for the population living in the red zone is the evacuation before the beginning of the eruption. Buildings would not offer safe shelter.
  • The operations of removal of the population last three days (72 hours) from the start of the operational phase of alarm.
  • The activation of the operational alarm phase won't be necessarily followed by a volcanic eruption. However, access to the area remains forbidden until the civil protection authorities provide different indications.
  • In the event of an eruption, the yellow area is exposed to lapilli and volcanic ash fallout. The evacuation of the population from this area will be assessed on the basis of the event in progress, wind direction and the magnitude of the eruption. Over-accumulation of ash could cause the collapse of the roofs.
  • It will not be possible to know immediately if and when people can come back to their houses after moving away during the "alarm phase". Keep up to date with the information provided by the civil protection authorities.

What to do?

With simple actions,yoy can help to better respond to an emergency:

  • Ask your Municipality about the Civil Protection Plan to find out which are the removal routes and the waiting areas: otherwise, demand its predisposition to know how to behave.
  • If you or one of your relatives need special assistance (people with disabilities, elderly people), inform your municipality and make sure that specific measures are provided for in the Civil Protection Plan.
  • Keep up to date and follow the instructions of the civil protection authorities (Municipality, Regional Civil Protection Department, National Civil Protection Department) via radio, television, press, internet, social media and toll-free numbers (Department's Contact Center and Regional Operational Room).
  • Volcanic eruptions are often preceded by earthquakes. For this reason, please check that your home is safe and adopt all the necessary measures to avoid situations that may represent a danger.
  • Avoid using basement and semi-basement rooms for living. working, recreational activities. In particular, do not use them for sleeping and do not allow access to them by unaccompanied children.
  • Always ventilate spaces before accessing them (especially rooms that have been closed for a long time or basements such as cellars and garages). 
  • Participate in exercises and information meetings on volcanic risk organized on your territory.


Share your knowledge with your family, your schoolmates and your colleagues: each of us should contribute to the dissemination of information on volcanic risk.

Keep informed about the status of volcano activity by consulting web and institutional social media (of Municipality, Regional Civil Protection Department, National Civil Protection Department), television, radio, press, toll-free numbers ( Department’s Contact Center, Regional Operational Room)

In this operational phase, the monitoring of the volcano is intensified and civil protection plans are checked.

During the attention phase, before a possible eruption, volcano activity can give rise to dangerous phenomena.

Bradyseism consists of a slow lowering and uplifting of the ground, during which earthquakes can occur. To learn how to behave in case of earthquake, read the rules of conduct at

Outgassing from the ground consists of increased emission of volcanic gases from the ground, especially in some areas. Some of these gases, in high concentrations, can be dangerous, therefore:

  • Avoid depressed areas and structures where volcanic gases can accumulate (basements, garages, empty swimming pools, water collection channels, underground tanks, wells, etc.); if you need to access them, however, reduce the time you stay there as much as possible and make sure there is someone outside who can render aid.
  • Avoid areas near volcanic gas emissions, especially during nighttime and during unfavorable weather conditions (no wind, cloudiness, fog).
  • If you notice potentially dangerous situations related to volcanic gas emissions, such as the presence of dead animals for no apparent reason, move away immediately and notify the municipality.

If you live in the red zone

  • Ask your municipality about the Civil Protection Plan to know the removal routes and waiting areas. Start thinking about whether, when the authorities provide instructions, you will move away in your car or in the vehicle that will be provided by the civil protection.
  • Also start thinking about whether you will move to another house of your property or to relatives or friends, outside the red and yellow zones, receiving financial assistance. Alternatively, you can benefit from the accommodation offered by the state, in the Region or Autonomous Province twinned with your municipality.
  • Remember to notify your municipality if you or a family member has special assistance needs for removal and alternative housing.


During this operational phase, the longest and most complex operations to be carried out in the red zone begin: relocation of people in hospitals and prisons, transfer of farm animals and securing the most important cultural assets.

If you live in the red zone
If you already want to move away at this stage, you can do so: you will receive a financial contribution from the State. In this case, be sure to inform your Municipality. If you decide to stay, be ready to leave as soon as the authorities advise you:

  • Make a list of essential things to bring with you (documents, medicines, glasses, etc.).
  • Be informed about removal routes to follow.
  • If you plan to use the means made available by the civil protection, inform your Municipality also signaling the presence of pets to organize the transport.
  • In case of not have done so yet, inform your Municipality if you or a family member have special needs for assistance.
  • If you or a family member are hospitalized in a health center, you will be transferred to another adequate health center outside the area at risk, which can be located in a region other than the one twinned with your Municipality.
  • Remember that at this stage, for safety reasons the access to the red zone will be controlled.

If you live in the yellow zone

  • Make sure you are equipped with protective masks, dust glasses, food, water, medicine, torches and ash removal tools.
  • If you or a family member have respiratory or cardiovascular disease, please consult your doctor to find out how to protect your health in case of an emergency situation.

In this operational phase, it is planned to move the population away from the red zone. The maximum estimated time for this activity is three days (72 hours). The operations are coordinated by the civil protection authorities.

If you live in the red zone

  • Go home and pack your bags. Be sure to take the essential things (documents, medicines, etc.).
  • Don't waste time saving goods and objects that you won't bring with you.
  • Before leaving the house, close doors, windows, gas, water and turn off the electrical system.
  • If you decide to leave the area autonomously, follow only the removal routes indicated in the plan and following the scheduled times. Make sure that your car has sufficient fuel.
  • If you choose to use assisted transport, get to the waiting area assigned to you by the municipal civil protection Plan, according to the timetable set by your Municipality. You can take your pet with you, according to the procedures provided by your Municipality.
  • The ban on the red zone can last for a long period of time and access to the area will be presided over by law enforcement authorities.

If you live in the yellow zone

  • Be prepared for a possible temporary relocation.

All people in the red zone either independently settled outside the risk zones or have been transferred to the twinned regions or autonomous provinces.

If you live in the yellow zone

  • In case of heavy volcanic ash fallout, on request of the civil protection authorities, you must temporarily leave your home. An accommodation will be assigned to you within your Municipality or in a Municipality within the Campania Region.
  • Before drinking water from the tap, make sure that local ordinances or notices do not forbid it; carefully rinse foods that have been in contact with volcanic ash.
  • If your residential area has not been evacuated during the volcanic ash fall, stay at home with the windows closed.
  • If you have to go out, it is recommended to wear a protective mask and dustproof glasses.
  • It is very dangerous to drive on road covered with ash. The car can be damaged and hinder emergency vehicles. Avoid the use of motorcycles.