Lake Bolsena
| Lake Bolsena | |
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| Lago di Bolsena(Italian) | |
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  Lake Bolsena  Lake Bolsena | |
| Location | Province of Viterbo,Central Italy |
| Coordinates | 42°36′N11°56′E/ 42.600°N 11.933°E |
| Type | crater lake |
| Primary inflows | None |
| Primary outflows | Marta |
| Catchment area | 159.5 km2(61.6 sq mi)[1] |
| Basincountries | Italy |
| Max. length | 13 km (8.1 mi)[2] |
| Max. width | 11 km (6.8 mi) |
| Surface area | 113.5 km2(43.8 sq mi)[1] |
| Average depth | 81 m (266 ft) |
| Max. depth | 151 m (495 ft) |
| Water volume | 9.2 km3(3.2×1011cu ft) |
| Residence time | 120 years[3] |
| Surface elevation | 305 m (1,001 ft) |
| Islands | 2 (Bisentina,Martana) |
| Settlements | seearticle |
| References | seearticle |
Lake Bolsena(Italian:Lago di Bolsena) is a lake ofvolcanicorigin in the northern part of theprovince of ViterbocalledAlto Lazio( "Upper Latium" ) orTusciain centralItaly.It is the largest volcanic lake in Europe.[4]Roman historic records indicate activity of theVulsinivolcano occurred as recently as 104 BC; it has been dormant since then. The two islands in the southern part of the lake were formed by underwater eruptions following the collapse that created the depression.
The lake is supplied entirely from the aquifer, rainfall and runoff, with one outlet at the southern end. A sewage treatment plant filters most of the raw sewage from the surrounding communities. Constructed in 1996, it features pipelines transporting the sewage from every major community around the lake to the treatment plant on the Marta River; that is, no effluents enter the lake.[5]Fertilizers are a second source of contamination. However, the chemical content of the lake is monitored at several stations around it.
The lake has a long historic tradition. The Romans called itLacus Volsinii,adapting theEtruscanname,Velzna,of the last Etruscan city to hold out against Rome, which was translocated after 264 BC, and its original location today has not been securely identified. The lake is bordered on one side by a modernized version of the Roman consular roadVia Cassia.In addition to the historic sites of all periods, Lake Bolsena is currently surrounded by numerous tourist establishments, largely for camping, agrotourism and bed and breakfasts.
One third of the lake was donated to theCatholic churchby the noble family Alberici of Orvieto. In recognition of the donation, the Alberici family was honored with a ceremony three times a year performed by theBishop of Orvieto.
Geography[edit]
 | This sectionneeds additional citations forverification.(August 2023) |
The lake has an oval shape typical ofcraterlakes. The long axis of theellipseis aligned in a north–south direction. The bottom is roughly conical, reaching a maximum depth at a point in the middle. The entire lake is surrounded by hills on the flanks and summits of which are the comuni. The watershed was home to 22,000 permanent residents in 2004, and 35,000 in the summer season.[5]
Elevations on the north of the lake are the highest, with a maximum of 702 m (2,303 ft). As the lake is at 305 m (1,001 ft), no hill is more than 397 m (1,302 ft) higher than it. On the northern rim of the caldera isSan Lorenzo Nuovo( "New Saint Lawrence" ), which was moved from an older site (a hypothetical San Lorenzo Vecchio, "Old Saint Lawrence" ) further down the slope to avoidmalaria.The northern shore of the lake once featured marshes, breeding grounds for the mosquitos that carry the disease. Currently it is agricultural. At the site of old San Lorenzo areEtruscanantiquities. To the north of San Lorenzo Nuovo and the caldera rim isAcquapendente.
The hills to the east are 600 m (2,000 ft) to 650 m (2,130 ft).Bolsenaextends upward on the northeast shore, withOrvieto14 km (8.7 mi) further to the northeast, at the edge of the volcanic region. On the southeast of the lake isMontefiasconeat an elevation of 633 m (2,077 ft), up on the ridge of Montefiascone caldera. To the south of the lake isMarta,on the right bank of the Marta River, sole effluent of the lake. The shore there is straight and developed. Elevations are within 100 m (330 ft) of the lake. Next to Marta areValentanoandCapodimonte,the latter being built on and around nearly the only headland on the lake, which forms a protective harbor. About 15 km (9.3 mi) to the south areTuscaniaandViterbo,the latter being the regional capital.
FromValentanonorth is the Latera caldera, a shallow crater perhaps half the size of Lake Bolsena, withLake Mezzano(usually too small for the map) at the western end. On its north rim isLatera.The floor of the caldera is mainly agricultural although the uncultivable rocky lava flows have been left forested. Although the hills on the west side of Lake Bolsena are only slightly higher than those on the south, the terrain is somewhat too rough for settlement. Fields extend as far as they can into v-shaped valleys and there is no flat shore.
The hills to the north loom over the lake. At their western edge areGrotte di CastroandGradoli.[6]
Geology[edit]
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Lake Bolsena is at the center of theVulsinii(or Vulsino) Volcanic District of the Roman Comagmatic Region. The lake formed when a circular area collapsed after the depletion of the underlying magmatic chamber that fed the whole volcanic district. Although it is generally known as a volcanic lake, like its southern neighborLake Braccianoit is not a crater lake nor does it occupy a caldera. The major calderas of the area are found close to the lake's rim (Latera to the west and Montefiascone to the south east).
Islands of the lake[edit]
| This sectionneeds additional citations forverification.(August 2023) |
Bisentina[edit]
With an area of 17 ha (42 acres), Bisentina is the largest island, and is accessible via a ferry service fromCapodimonte.On the island are groves ofevergreen oaks,Italian gardens, and various monuments: thechurchofSaint JamesandSaint Christopherwith itscupolabuilt by thearchitectJacopo Barozzi da Vignola;the Franciscanconvent;theRocchina,a small temple dedicated toSaint Catherine.The latter was constructed in an octagonal floorplan byAntonio da Sangallo,over an Etruscancolumbariumpreviously erected on a rocky outcrop on the lake. Another monument, thechapelof theCrucifix,containsfrescosof the fifth century. TheMalta dei Papi,a formerprisonforecclesiasticsfound guilty ofheresy,was shaped from a small cave with a trapdoor placed at a height of 20 m (66 ft). Mysterious in its creation, located under Mount Tabor, the highest point of the island, cited byDante Alighierias a life-prison. "Malta dei Papi is a deep tunnel dug into the tuff at the end of which there is an underground chamber of about 6 meters built around a well, and above which there is a circular opening used to collect water. The waterproof plaster found on its inside walls reveal that the structure was used as a cistern in Roman Times. However, its origin is probably much older than that and linked to the volcanic thermal waters that flow underneath.
Forgotten after being turned for a long time into a stage of atrocities as a prison for heretics, this chamber became subject of occultist conversation in the late 19th century in Madame Blavatsky’s theosophic society, who considered this place to be one of the secret entrances to the underground kingdom of Agarthi, "the Inaccessible".[7]
TheEtruscansand theRomansleft few traces of their stay on the island. In the 9th century it provided refuge from the incursions of theSaracens.
About 1250, it became the property of the lord of Bisenzio, who abandoned it and burned it following disagreements with the inhabitants of the island. In 1261,Urban IVreconquered it. The island was destroyed again in 1333 byLouis IV of Bavaria,accused of heresy and excommunicated by the pope. The property of theFarnesefamily from 1400 onwards, it had a period of prosperity and was visited by many popes.
In 1635, it was governed byOdoardo Farnese,duke ofCastro,who entered into conflict with the Church, resulting in the total destruction of Castro. The two islands returned to the Church's control but were soon ceded again. The princess Beatrice Spada Potenziani, wife of the duke Fieschi Ravaschieri, owned it until 2017. Where it was sold to a foundation.
Martana[edit]
Located opposite the town ofMarta,the island of Martana is reputed to have once guarded therelicsofSaint Christineto keep them from falling into the hands of thebarbarians.Later, it is said that, during the dominion of theGoths,their queenAmalasunthawas assassinated there.
The island is currently private property and no visitors are allowed.
Marta outlet[edit]
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The Marta is anemissaryof Lake Bolsena to the east of the community ofMarta,emptying into theTyrrhenian Sea.After passing through Marta,TuscaniaandTarquinia,it reaches the sea near Lido di Tarquinia. Salt pans have been constructed between its mouth and that of the Mignone river.
Comunibordering the lake[edit]
The followingcomuniare situated on the shore of Lake Bolsena:
Each has a designated length of beach for summer swimming. Some of these have facilities such as cafés, restaurants and boat rentals.
Other nearby towns areSorano,Pitigliano,AcquapendenteandOrvieto,withOnanoto the northwest.
See also[edit]
Notes[edit]
- ^abMosello, Arisci & Bruni (2004),p. 1.
- ^Washington (1906),p. 3.
- ^Mosello, Arisci & Bruni (2004),pp. 2, 9. This is the theoretical water renewal time.
- ^Ferlei-Brown, Nicola (14 July 2015)."Lake Bolsena A Volcanic Miracle".Italy Magazine.
- ^abMosello, Arisci & Bruni (2004),p. 2.
- ^Washington (1906),pp. 3–4.
- ^Isola Bisentina website.Accessed 9 August 2023.
Bibliography[edit]
- Mosello, Rosario; Arisci, Silvia; Bruni, Piero (2004)."Lake Bolsena (Central Italy): an updating study on its water chemistry"(PDF).Journal of Limnology.63(1): 1–12.doi:10.4081/jlimnol.2004.1.Archived fromthe original(PDF)on 20 May 2005.
- Washington, Henry Stephens (1906).The Roman Comagmatic Region.Washington D. C.: Carnegie Institution of Washington.
External links[edit]
- "The Lake of Bolsena".lagodibolsena.org. Archived fromthe originalon 19 September 2009.Retrieved28 April2009.
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