Solfatara ( it, Solfatara di Pozzuoli) is a shallow

volcanic crater A volcanic crater is an approximately circular depression in the ground caused by Volcano, volcanic activity. It is typically a bowl-shaped feature containing one or more vents. During Types of volcanic eruptions, volcanic eruptions, molten magm ...

Pozzuoli Pozzuoli (; ; ) is a city and ''comune'' of the Metropolitan City of Naples, in the Italian region of Campania. It is the main city of the Phlegrean Peninsula. History Pozzuoli began as the Greek colony of ''Dicaearchia'' ( el, Δικα ...

, near

Naples Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adminis ...

, part of the

Phlegraean Fields The Phlegraean Fields ( it, Campi Flegrei ; nap, Campe Flegree, from Ancient Greek 'to burn') is a large region of supervolcanic calderas situated to the west of Naples, Italy. It was declared a regional park in 2003. The area of the calde ...

( it, Campi Flegrei) volcanic area. It is a

dormant volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

, which still emits jets of

steam Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization ...

with

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

ous fumes. The name comes from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

, ''Sulpha terra'', "land of

", or "sulfur earth". 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 Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

interacts with

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

. The crater floor was a popular tourist attraction until 2017, as it has many

fumaroles A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...

and

mud pools A mudpot, or mud pool, is a sort of acidic hot spring, or fumarole, with limited water. It usually takes the form of a pool of bubbling mud. The acid and microorganisms decompose surrounding rock into clay and mud. Description The mud of a mud ...

. The area is well known for its

bradyseism 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 or hydrothermal activity, particularly in volcanic calderas. ...

. The vapours had been used for medical purposes since Roman times. Solfatara crater.jpg, Panoramic view of the crater towards the southeast Mud pool in Solfatara crater.jpg, Close-up view of a mud pool Medium fumarole in Solfatara crater.jpg, Medium size fumarole in Solfatara Fumarole in Solfatara crater (close up).jpg, Biggest fumarole in Solfatara This volcano is where the

thermoacidophilic A thermoacidophile is an extremophilic microorganism that is both thermophilic and acidophilic; i.e., it can grow under conditions of high temperature and low pH. The large majority of thermoacidophiles are archaea (particularly the Thermoproteot ...

archaeon Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebact ...

Sulfolobus solfataricus ''Saccharolobus solfataricus'' is a species of thermophilic archaeon. It was transferred from the genus ''Sulfolobus'' to the new genus ''Saccharolobus'' with the description of Saccharolobus caldissimus in 2018. It was first isolated and disco ...

'' 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. Saint Proculus (the

patron saint A patron saint, patroness saint, patron hallow or heavenly protector is a saint who in Catholicism, Anglicanism, or Eastern Orthodoxy is regarded as the heavenly advocate of a nation, place, craft, activity, class, clan, family, or perso ...

of Pozzuoli) and

Saint Januarius Januarius ( ; la, Ianuarius; Neapolitan language, Neapolitan and it, Gennaro), also known as , was Roman Catholic Archdiocese of Benevento, Bishop of Benevento and is a Christian martyrs, martyr and saint of the Catholic Church and the Eastern ...

(the patron saint of Naples) were beheaded at Solfatara in 305. In 2017, three people—an 11-year-old boy and his parents—died, when they fell into a chasm. Initial rumors that claimed that the boy had entered an off-limits area of the crater were declared false by an eyewitness who had watched the scene unfold from her balcony. According to the eyewitness, the family were on the official walking path, when the 11-year-old slipped into the unsecured chasm. His parents died in an attempt to save him. The only survivor was the boy's 7-year-old brother.

References

* Campanian volcanic arc Volcanoes of Italy Landforms of Campania Phlegraean Fields {{Campania-geo-stub