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Discussion Starter · #1 · (Edited)
Campi Flegrei (Phlegraean Fields)

The Phlegraean Fields (aka Campi Flegrei, that means "burning fields") it's the site of one of the largest supervolcanoes in relatively recent times.
Erupting 200 cubic kilometres of magma 39.000 years ago, and still active,
it is one of the potential candidates for a supervolcanic event in 2012 that could potentially destroy all Europe.



The Phlegraean Fields, also known as Campi Flegrei, (from Greek φλέγος, burning), is a large 13 kilometres (8.1 mi) wide caldera
situated to the west of Naples, Italy. It was declared a regional park in 2003. Lying mostly underwater, the area comprises 24 craters and volcanic edifices.
Hydrothermal activity can be observed at Lucrino, Agnano and the town of Pozzuoli. There are also effusive gaseous manifestations in the Solfatara crater,
which is known as the mythological home of the Roman god of fire, Vulcan. The area also features bradyseismic phenomena,
which are most evident at the Macellum of Pozzuoli which in the 18th century was mis-identified as a Temple of Serapis,
as geologists puzzled over bands of boreholes (Gastrochaenolites) left by marine Lithophaga molluscs on three standing marble columns,
showing that the level of the site in relation to sea level had varied. This area is monitored by the Vesuvius Observatory.



Geological phases

Three geological phases or periods are recognised and distinguished.

The First Phlegraean Period. It is thought that the eruption of the Archiflegreo volcano occurred about 39.28 ± 0.11 ka.
The dating of the Campanian Ignimbrite (CI) eruption to ~37,000 calendar years B.P. draws attention to the coincidence of this volcanic catastrophe
and the suite of coeval, Late Pleistocene biocultural changes that occurred within and outside the Mediterranean region.
These included the Middle to Upper Paleolithic cultural transition and the replacement of Neanderthal populations by anatomically modern Homo sapiens,
a subject of sustained debate. No less than 150 km3 of magma were extruded in the CI eruption, the signal of which can be detected in Greenland ice cores.
As widespread discontinuities in archaeological sequences are observed at or following the CI event, a significant interference with ongoing human processes
in Mediterranean Europe is hypothesized. Abstract (older estimate ~37,000 years ago),
erupting about 200 cubic kilometres (48 cu mi) of magma (500 cubic kilometres (120 cu mi) bulk volume) to produce the Campanian Ignimbrite.
New research led by Liubov Vitalievna Golovanova and Vladimir Borisovich Doronichev of the ANO Laboratory of Prehistory in St. Petersburg, Russia,
supports the hypothesis that these eruptions drove Neanderthals to extinction and cleared the way for modern humans to thrive in Europe and Asia.
The area is characterised by banks of piperno and pipernoid grey tuff at Camaldoli hill, like in the northern and western ridge of Mount Cumae;
other referable deep products are those found at Monte di Procida, recognizable in the cliffs of its coast.

The Second Phlegraean Period. Between the 35,000-10,500 years ago, it is characterized by the yellow tuff that constitutes the rests of an immense
underwater volcano (having a diameter of ca. 15 kilometres (9.3 mi) and Pozzuoli to its center) Approximately 12,000 years ago
the last major eruption occurred, forming a smaller caldera inside the main one, centered on the town of Pozzuoli.
This event produced the Neopolitan yellow tuff, referring to the characteristic yellow rocks there.

The Third Phlegraean Period. Dated between 8,000 – 500 years ago, it is characterized by white pozzolana,
the material that forms the majority of volcanos in Flegrei Fields. Broadly speaking, it can be said there was an initial activity to the south-west in the zone
of Bacoli and Baiae (10.000-8.000 years ago); an intermediate activity in an area centred between Pozzuoli,
Spaccata Mountain and Agnano (8.000-3.900 years ago); and a more recent activity, moved towards the west to form Lake Avernus
and Monte Nuovo (New Mountain) (3,800–500 years ago).

The caldera, which now is essentially at ground level, is accessible on foot. It contains a large number of fumaroles, from which steam can be seen issuing,
and over 150 pools of boiling mud at last count. Several subsidiary cones and tuff craters lie within the caldera. One of these craters is filled by Lake Avernus.
In 1538, an eight-day eruption in the area deposited enough material to create a new hill, Monte Nuovo.
It has risen about 2 metres (7 ft) from ground level since 1970.
 

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Discussion Starter · #3 · (Edited)
Piscina Mirabilis (Bacoli)
Descensio ad Inferos

The Piscina Mirabilis was a freshwater cistern on the Bacoli cliff at the western end of the Gulf of Naples, southern Italy.
One of the largest freshwater cisterns built by the ancient Romans,
it was situated there in order to provide the Roman western imperial fleet at Portus Julius with drinking water.


Piscina Mirabilis by Chiara Giangrande, on Flickr

The cistern was dug entirely out of the tuff cliff face and was 15 metres high/deep (ca. 49 feet),
72 metres long (ca. 236 feet), and 25 metres wide (ca. 82 feet). The capacity/volume was 12,600 cubic metres (ca. 445,000 cubic feet).
It was supported by vaulted ceilings and 48 pillars.
It was supplied with water from the main Roman acqueduct, the Aqua Augusta, that brought water from sources in Serino near Avellino,
100 kilometres distant, to Naples.

The ancient cistern is in private hands but parts of it may still be visited.


grey&green by AgoInUnPagliaio_NeedleInAhaystack, on Flickr


Emptiness by FedeSK8, on Flickr


Archeoarchipnosi by nikoletto, on Flickr


Prospettive, Piscina Mirabilis by fabbiomenna...in Tridentum, on Flickr


ops.. by kindaska, on Flickr


Piscina mirabilis (Miseno - Italy) by Daniele Pollice, on Flickr
 

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Discussion Starter · #4 ·
Antro della Sibilla (Cuma)
The Cave of the Sibyl

Cumae is perhaps most famous as the seat of the Cumaean Sibyl. Her sanctuary is now open to the public.
In Roman mythology, there is an entrance to the underworld located at Avernus, a crater lake near Cumae,
and was the route Aeneas used to descend to the Underworld.


CUMA00 by ivomolli, on Flickr

The Temple of Zeus at Cumae was transformed into a Christian basilica at the end of the fourth century.
At Cumae was set a widely influential Christian work of the second century, The Shepherd of Hermas said by
its author to have been inspired by way of visions.
The colony was built on a large rise, the seaward side of which was used as a bunker and gun emplacement
by the Germans during World War II.


L'antro da fuori. by Metius, on Flickr


sibilla cumana by Shamballah, on Flickr


Nam Sibyllam quidem Cumis ego ipse oculis meis... by Metius, on Flickr
 

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Discussion Starter · #5 ·
Solfatara Caldera (Pozzuoli)
The Burning Fields

Solfatara is a shallow volcanic crater at Pozzuoli, near Naples, part of the Campi Flegrei volcanic area. It is a dormant volcano, which still emits
jets of steam with sulfurous fumes. The name comes from the Latin, Sulpha terra, "land of sulfur", or "sulfur earth".


VOLCANO SOLFATARA / BOCCA GRANDE * DSCF3035 by JAMES MARSHALL D, on Flickr

It was formed around 4000 years ago and last erupted in 1198 with what was probably a phreatic eruption - an explosive steam-driven eruption
caused when groundwater interacts with magma.
The crater floor is a popular tourist attraction, as it has many fumaroles and mud pools. The area is well known for its bradyseism.
The vapours have been used for medical purposes since Roman times.
This volcano is where the thermoacidophilic archaeon Sulfolobus solfataricus was first isolated.
The archaeon is named for the volcano, as most species of the genus Sulfolobus are named for the area where they are first isolated.
In 305, this is the location where the patron of Pozzuoli, Saint Proculus, and patron of Naples, Saint Januarius were beheaded.


Solfatara (Pozzuoli) by russoroby52, on Flickr


Pozzuoli Solfatara - 3 by Julia Janßen, on Flickr


Solfatara by live-is-a-curse, on Flickr


Ma... by Maxime Bermond, on Flickr


maybe the hell by kikkavodka, on Flickr
 

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Discussion Starter · #9 ·
Flavian Amphitheater (Pozzuoli)

The Flavian Amphitheater (Anfiteatro flaviano puteolano), located in Pozzuoli, is the third largest Roman amphitheater in Italy.
Only the Roman Colosseum and the Capuan Amphitheater are larger. It was likely built by the same architects
who previously constructed the Roman Colosseum. The name Flavian Amphitheater is primarily associated with the Roman Colosseum.


Amphitheatrum Flavium by abibrooks, on Flickr

It was begun under the reign of the emperor Vespasian and probably finished under the reign of his son Titus. The arena can hold up to 20,000 spectators.
The interior is mostly intact and one can still see parts of gears which were used to lift cages up to the arena floor.
In 305, the arena was the setting for the persecutions of the patron of Pozzuoli, Saint Proculus, and the patron saint of Naples, Saint Januarius.
After surviving being thrown to the wild beasts in the arena, the two were beheaded at the nearby Solfatara.
The elliptical structure measures 147 x 117 meters (482 x 384 feet), with the arena floor measuring 72.22 x 42.33 meters (237 x 139 feet).
The amphitheater can be visited by taking line number 2 of the Naples, Italy subway, and getting off at the Pozzuoli stop.
The Flavian Amphitheater is the second of two Roman amphitheaters built in Pozzuoli. The smaller and older amphitheater (Anfiteatro minore)
has been almost totally destroyed by the construction of the Rome to Naples railway line. Only a dozen arches of this earlier work still exist.
This lesser amphitheater measured 130 x 95 meters (427 x 312 feet).
The site of the structure was chosen at the nearby crossing of roads from Naples, Capua and Cumae.
It was abandoned when it was partially buried by eruptions from the Solfatara volcano. It was during the medieval period that the marble used
on the exterior was stripped. This had the fortunate result of leaving the interior alone and perfectly preserved.
Excavations of the site were performed 1839 to 1845, 1880 to 1882, and finally in 1947.


IMG_2198 by yoxito, on Flickr


Amphitheatre corridors by Baba Mdogo, on Flickr


Anfiteatro Flavio, Pozzuoli, Italy by Andrew Withey, on Flickr


hypogeum by anubis333, on Flickr


Toes by InkSpot's Blot, on Flickr
 

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Discussion Starter · #10 · (Edited)
Rione Terra (Pozzuoli)

Rione Terra is the oldest part of Pozzuoli. This quarter; rising ste the sea, was the oldest rur Greek city, the acropolis,
the "castrunm" and the religious centre. It preserves consider of the street network of when a Roman colony was estabilished in Pozzuoli.
Today Rione Terra is a picturesque and quiet the ancient fortress dominates, from up high, the ferries' pier as well as the Yalta promenade.
This quarter, however, has been deserted and inaccessible since 1970 when it was very hastily evacuated
due to bradyseism that was closing in. Rione Terra has, since then, remained closed.


Panoramica Del Rione Terra, Pozzuoli by Salvatore Di Stadio, on Flickr

Bradyseism is the gradual uplift (positive bradyseism) or descent (negative bradyseism) of part of the Earth's surface caused by the filling or emptying
of an underground magma chamber and/or hydrothermal activity, particularly in volcanic calderas. It can persist for millennia in between eruptions
and each uplift event is normally accompanied by thousands of small to moderate earthquakes. The word derives from the ancient greek words "bradus",
meaning slow, and "sism" meaning movement, and was coined by Arturo Issel in 1883.


During the past 2000 years, vertical movements (bradysism) of several meters amplitude have occurred in the active volcanic caldera
of the Phlaegrean Fields and notably in the bay of Pozzuoli, near Naples (Southern Italy).
Biological sea level indicators (boring Lithophaga shells) were documented up to 7 meters above present sea level on the three marble columns
of the Roman marketplace. Fossil specimens of the coral Astroides calycularis were also found 7 meters above present sea level, in a former marine cave,
1 km east of the Roman marketplace (Rione Terra cliff).


Many building were destroyed or damaged because of the uplift of the Earth surface. Today Rione Terra is being renovating.

Also the old roman underground city is accessible.


Rione Terra by Cassandra Cumana, on Flickr


Rione Terra by Cassandra Cumana, on Flickr


rione terra di notte by raffale64, on Flickr
 

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Discussion Starter · #11 ·
Macellum (Pozzuoli)
Temple of Serapis

The Macellum of Pozzuoli was the macellum or market building of the Roman colony of Puteoli, now known as Pozzuoli.
When first excavated in the 18th century, the discovery of a statue of Serapis led to the building being mis-identified as the city's serapeum
or Temple of Serapis. A band of borings or Gastrochaenolites left by marine Lithophaga bivalve molluscs on three standing marble columns
indicated that these columns had remained upright over centuries while the site sank below sea level, then re-emerged.
This puzzling feature was the subject of debate in early geology, and eventually led to the identification of bradyseism in the area,
showing that the Earth's crust could be subject to gradual movement without destructive earthquakes.


Serapide Temple ( Macellum)(- Pozzuoli by Goldenpixel, on Flickr

More recent investigations of the vertical movements have shown that the site is near the centre of the Campi Flegrei (Phlegraean Fields) caldera
and has been subject to repeated "slow earthquakes" or bradyseism of this shallow caldera resulting in relatively slow subsidence over long periods,
drowning the ruin, punctuated by periods of relatively rapid uplift that caused it to re-emerge. After a long subsidence through Roman times,
there was a period of uplift in the Middle Ages around AD 700 to 800, then after more subsidence the land rose again from around 1500 up to
the last eruption in 1538. The land again subsided gradually, then between 1969 and 1973 the land rose by about 1.7 metres (5.6 ft).
Over the following decade there was a little subsidence, then between 1982 and 1994 there was uplift of almost 2 metres (6.6 ft).
Concerns about risks of earthquake damage and possible eruption led to temporary evacuation of the city of Pozzuoli.
Detailed measurements indicated that the caldera deformation formed a nearly circular lens centred near Pozzuoli.
Various models have been produced to find mechanisms explaining this pattern.


Pozzuoli, " Macellum " by roxanna4evernever, on Flickr


P1000857a by Marchal, on Flickr


Pozzuoli, Il Serapeo by roxanna4evernever, on Flickr
 

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Great pics of "Campi Flegrei" Pincio. One of the most scenic drives that I can remember was along the Domiziana Roadway that runs through the fields. Btw, I used to work at the NATO Base in nearby Bagnoli a few years ago. :cheers:
 

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Discussion Starter · #16 ·
http://www.volcanodiscovery.com/phl...-about-200-shocks-caused-by-bradyseismus.html

Earthquakes: seismic swarm at Campi Flegrei, about 200 shocks caused by bradyseismus

Saturday Sep 08, 2012 09:00 AM


up in the air #2 di FedeSK8, su Flickr

A new swarm of earthquakes was recorded under the Phlegean Fields near Naples yesterday (8 Sep). The quakes are related to what is called bradyseismus, a slow periodic ground inflation and deflation, which make the
land of the Phlegraean Fields rise and sink over years.
On the morning of 8 September, about 200 earthquakes of magnitude up to 1.6 were detected by the Osservatorio Vesuviano (OV). Its director, Marcello Martini, said that this phenomenon repeats periodically and is linked to the process of deformation of the Phlegraean Fields.
Earthquakes today have not surprised the experts. Small earthquake swarms were already recorded in the Campi Flegrei very recently: on August 4 last year, when the shocks were only a few tens, and between 19 and 20 April, with 21 earthquakes of magnitude 1.4 maximum.
The process of deformation of this area (which is one of what often has been described as a "supervolcano") is continuous. The ground rises and falls periodically and changes in this movement are often accompanied by small earthquakes.
For example, Martini explains, "between 1982 and 1985 began a slow decline that ended in 2005. Since then, a slow rise of the land began that is still continuing today."
"What that past experience has taught us," says the expert," is that earthquakes can occur with the lifting process. Certainly, however, the phenomenon of today still has to be studied. There is also the fact, he added, that the peaks of speed in the movement caused by bradyseismus has been reduced by 10 times compared to the maximum of 15 cm per month measured 30 years ago. At present this is not a disturbing phenomenon, but we follow it very carefully."
According to OV there is no relationship between the swarm and the drilling recently launched as part of an international project on supervolcanoes led by Italy's INGV. "The drilling - says Martini - reached only 200 meters this time, while in the past drillings were made to up to 400 m depth, and second, the drilling is in the Bagnoli area, while the swarm is concentrated in the center of the caldera in the area of ​​Pozzuoli."


Piscina Mirabilis di FedeSK8, su Flickr
 
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