The Phlegraean Fields (Italian: Campi Flegrei, Italian: [ˈkampi fleˈɡrɛːi]; Neapolitan: Campe Flegree) is a large caldera volcano west of Naples, Italy.[a] It is part of the Campanian volcanic arc, which includes Mount Vesuvius, about 9 km (6 miles) east of Naples. The Phlegraean Fields is monitored by the Vesuvius Observatory.[6] It was declared a regional park in 2003.
Phlegraean Fields | |
---|---|
Highest point | |
Elevation | 458 m (1,503 ft)[1] |
Coordinates | 40°49′37″N 14°08′20″E / 40.827°N 14.139°E / 40.827; 14.139[1] |
Naming | |
Native name | Campi Flegrei (Italian) |
Geography | |
Location | Metropolitan City of Naples, Campania, Italy |
Geology | |
Age of rock | 40,000 years |
Mountain type | Caldera[1] |
Volcanic arc/belt | Campanian volcanic arc |
Last eruption | 29 September to 6 October 1538[1] |
The area of the caldera consists of 24 craters and volcanic edifices; most of them lie under the Gulf of Naples. There are effusive gaseous manifestations in the Solfatara crater, which was believed in ancient Rome to be the home of Vulcan, the god of fire.[7] The area features bradyseismic phenomena, which are most evident at the Macellum of Pozzuoli (misidentified as a temple of Serapis): bands of boreholes left by marine molluscs on marble columns show that the level of the site in relation to sea level has varied. Hydrothermal activity can still be observed at Lucrino, Agnano and the town of Pozzuoli.
At present, the Phlegraean Fields area comprises the Naples districts of Agnano and Fuorigrotta, the area of Pozzuoli, Bacoli, Monte di Procida, Quarto, the Phlegraean Islands (Ischia, Procida and Vivara).[citation needed]
The Solfatara crater is accessible on foot and contains many steam-emitting fumaroles and over 150 pools (at the last count) of boiling mud. Several subsidiary cones and tuff craters, one filled by Lake Avernus, lie within the caldera.
The magma underlying the Phlegraean Fields produces lavas of varying composition but generally rich in potassium. Trachyte is the most common eruptive product, unusually alkali-rich in some cases. Peralkaline phonolitic trachyte and latite have also been produced, and there is rare trachybasalt.[8]
Three geological phases or periods are recognised and distinguished.[9]
Volcanic deposits indicative of eruption have been dated by argon at 315,000, 205,000, 157,000 and 18,000 years ago.[citation needed]
In 1538, an eight-day eruption in the area deposited enough material to create a new hill, Monte Nuovo. It has risen about 2 m (7 ft) from ground level since 1970.
The volcanic island of Ischia suffered three destructive earthquakes in 1828, 1881, and the most destructive one in 1883, with a magnitude of 4.2–5.2 and causing catastrophic shaking assigned XI (Extreme) on the MCS scale. Extreme damage was reported on the island, and over 2,000 residents perished.[18]
A 2009 journal article stated that inflation of the caldera centre near Pozzuoli might presage an eruptive event within decades.[19] In 2012 the International Continental Scientific Drilling Program planned to drill 3.5 kilometres (11,000 feet) below the earth's surface near Pompeii, in order to monitor the massive molten rock chamber below and provide early warning of any eruption. Local scientists were worried that drilling could precipitate an eruption or earthquake; programme scientists said it was no different from industrial drilling in the area. The drilling was halted in 2010, but later resumed. A Reuters article emphasized that the area could produce a "super volcano" that might kill millions.[20]
A study from the Istituto Nazionale di Geofisica e Vulcanologia reported that the volcanic unrest of the Campi Flegrei caldera from January 2012 to June 2013 was characterised by rapid ground uplift of about 11 cm (4 in), with a peak rate of about 3 cm (1 in) per month during December 2012. It added that from 1985 to 2011 the dynamics of ground uplift were mostly linked to the caldera's hydrothermal system, and that this relation broke down in 2012. The driving mechanism of the ground uplift changed to periodical emplacement of magma within a flat sill-shaped magmatic reservoir about 3,000 m (9,843 ft) in depth, 500 m (1,640 ft) south from the port of Pozzuoli.[21]
In December 2016, activity became so high that an eruption was feared.[22] In May 2017 a new study by University College London and the Vesuvius Observatory published in Nature Communications concluded that an eruption might be closer than previously thought. The study found that the geographical unrest since the 1950s has a cumulative effect, causing a build-up of energy in the crust and making the volcano more susceptible to eruption.[23][24][25][26]
On 21 August 2017 there was a magnitude 4 earthquake on the western edge of the Campi Flegrei area.[27] Two people were killed and many more people injured in Casamicciola on the northern coast of the island of Ischia, which is south of the epicentre.[28]
The reason for the seismicity and bulging ground is not known as of 2023[update]. According to one model, called in a Scientific American article the shallow magma model, magma is pushing to break through the surface, making an explosive eruption with magma flow likely. In what has been termed the hot fluids model, steam and hot gases generated deeper underground are the cause; in this case activity could stop abruptly, or lead to a phreatic eruption of hot liquids, gases and rock fragments, rather than lava. While very dangerous, it is less so than a magma eruption. An answer to this question would help to estimate how likely this volcano, and other large volcanoes and supervolcanoes, are to erupt, and what warning signs to look out for.[29]
A February 2020 status report indicated that earth uplift around Pozzuoli continued at steady rates, with a maximum average of 0.7 cm per month since July 2017. Gas emissions and fumarole temperatures did not change significantly.[30][31] In May 2024 the ground was reported to be rising by 2 cm per month, with the rate increasing.[32]
On April 26, 2020, a moderate earthquake swarm hit Campi Flegrei caldera, with about 34 earthquakes ranging between magnitude 0 and magnitude 3.1 centred around the port city of Pozzuoli. The strongest quake in the sequence was of magnitude 3.1, the strongest at the time since the last major period of unrest and rapid uplift in 1982-1984. However, no new fumaroles were reported.[33]
Volcanic activity was reported in January 2022 to be increasing.[34] In the year to September 2023 seismic activity had intensified, particularly in the later months. On 27 September 2023, a magnitude 4.2 earthquake—the strongest in 40 years—prompted the preparation of contingency plans to evacuate up to 360,000 people in the area.[35] Despite a further 4.0 quake on 2 October, most volcanologists consider that a major eruption is not expected imminently.[36] The best-case scenario was deemed to be the activity ending, as happened after much activity on the 1980s; the worst would be an eruption like the one of 1538. A study by Italy's National Institute of Geophysics and Volcanology (INGV) and University College London (UCL) in June 2023 concluded that the volcano was edging towards "breaking point" and in an "extremely dangerous state".[37] Nello Musumeci, Italian minister for civil protection, was to ask Neapolitan local officials for an "acceleration in the drafting of exodus plans in the event of an emergency";[35] he said that evacuation would only be carried out in the event of "extreme necessity".[36] Mass evacuation plans were to be tested at the end of May 2024.[38]
Intense seismic activity continues in 2024.[39][40] On 20 May 2024, seismic activity intensified, with a swarm of 150 earthquakes in a few hours, one of magnitude 4.4 causing fear among the population of Pozzuoli and some cracks and minor damage to buildings. Schools and a prison were evacuated.[32][38]
In respect of its 18th and 19th century role in the development of geoscience, not least volcanology, this locality was included by the International Union of Geological Sciences (IUGS) in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022.[41]
Italian wine, both red and white, under the Campi Flegrei DOC appellation comes from this area. Grapes destined for DOC production must be harvested up to a maximum yield of 12 tonnes/hectare for red grape varieties, and 13 t/ha for white grape varieties. The finished wines need to be fermented to a minimum alcohol level of 11.5% for reds and 10.5% for whites. While most Campi Flegrei wines are blends, varietal wines can be made from individual varieties, provided the variety used comprises at least 90% of the blend and the wine is fermented to at least 12% alcohol for reds and 11% for whites.[42]
Red Campi Flegrei is a blend of 50–70% Piedirosso, 10–30% Aglianico and/or Sciascinoso and up to 10% of other local (both red and white) grape varieties. The whites are composed of 50–70% Falanghina, 10–30% Biancolella and/or Coda di Volpe, with up to 30% of other local white grape varieties.[42]
Campi Flegrei has had strategic and cultural importance.
Significance of Ecological Factors in the Middle to Upper Paleolithic Transition