Avellino eruption
Encyclopedia
The Avellino eruption of Mount Vesuvius
refers to a Plinian-type eruption that occurred in the 2nd millennium BC
and is estimated to have had a VEI
of 6. It is the source of the Avellino Pumice deposits named from the comune
of Avellino
in Campania
where they have been found extensively.
("the white pumice phase"), while a second, more intense explosion raised a column of 31 km (101,706 ft) depositing 1.25 km3 of grey pumice ("the grey pumice phase"). These pumices appearing in Apulia
n pottery can be used to establish relative chronology of pottery phases.
A 2008 study of the lithofacies
(deposits from the eruption) distinguishes three phases. Pyroclastic flow
s (PDC's) of Phases 1 and 2 were generated by "magmatic fragmentation" and had "small dispersal areas" mainly on the slopes of Vesuvius. Phase 3 was created by "phreatomagmatic
fragmentation," in which clastic fragments are driven by superheated steam from ground water mixed with the other gases released from the magma. The authors characterize Phase 3 as "the most voluminous and widespread in the whole of Somma-Vesuvius' eruptive history." Some facies a few cm thick were found 25 km (15.5 mi) from the source. The vent was 2 km (1.2 mi) west of today's center. About 50 cm (19.7 in) fell on Avellino.
. A range of 2000 BC — 1500 BC includes the great majority of estimates. Ample opportunity to obtain Carbon-14 dates from charcoal and soil buried under the deposits has existed and still exists. Sporadic Carbon dating continues, with each scientist claiming to have obtained "the latest." Consistency with previous and subsequent work remains elusive. Since a real and very precise calendar date of the eruption must have existed, variation in estimations can only be the result of limitations to the carbon-dating method, which, given a plenitude of reliably emplaced samples, can only produce a date within a window of roughly 500 years in a maximum elapsed time of roughly 4000 years or 1/8 (12.5%).
According to Giardino, estimations fall into two ranges: 1880-1680 BC and 1684-1535 BC. He prefers the earlier, tagging it as "the end of the Early Bronze Age."
A study published in 1990 by Vogel and others suggested that the Avellino Eruption was responsible in part for the climatic disturbances of the 1620s BC
. The latter were verified by "tree-ring series" and "ice-core layers." The authors had just obtained carbon dates of 3360±40 BP
, or 1617-1703 calibrated BC. They were suggesting a coincidence of a number of eruptions, such as the Santorini
explosion, that destroyed Minoan
civilization. The hypothesis remains unverifiable a generation later, due to the overall imprecision of the dates.
settlements. The remarkably well-preserved remains of one were discovered in May 2001 at Croce del Papa
near Nola
by Italian archaeologists, with hut
s, pot
s, livestock
and even the footprint
s of animals and people, as well as skeletons. The residents had hastily abandoned the village, leaving it to be buried under pumice
and ash in much the same way that Pompeii was later preserved.
Mount Vesuvius
Mount Vesuvius is a stratovolcano in the Gulf of Naples, Italy, about east of Naples and a short distance from the shore. It is the only volcano on the European mainland to have erupted within the last hundred years, although it is not currently erupting...
refers to a Plinian-type eruption that occurred in the 2nd millennium BC
2nd millennium BC
The 2nd millennium BC marks the transition from the Middle to the Late Bronze Age.Its first half is dominated by the Middle Kingdom of Egypt and Babylonia. The alphabet develops. Indo-Iranian migration onto the Iranian plateau and onto the Indian subcontinent propagates the use of the chariot...
and is estimated to have had a VEI
Volcanic Explosivity Index
The Volcanic Explosivity Index was devised by Chris Newhall of the U.S. Geological Survey and Stephen Self at the University of Hawaii in 1982 to provide a relative measure of the explosiveness of volcanic eruptions....
of 6. It is the source of the Avellino Pumice deposits named from the comune
Comune
In Italy, the comune is the basic administrative division, and may be properly approximated in casual speech by the English word township or municipality.-Importance and function:...
of Avellino
Avellino
Avellino is a town and comune, capital of the province of Avellino in the Campania region of southern Italy. It is situated in a plain surrounded by mountains 42 km north-east of Naples and is an important hub on the road from Salerno to Benevento.-History:Before the Roman conquest, the...
in Campania
Campania
Campania is a region in southern Italy. The region has a population of around 5.8 million people, making it the second-most-populous region of Italy; its total area of 13,590 km² makes it the most densely populated region in the country...
where they have been found extensively.
Characteristics of the eruption
"Assessment of volcanological factors" in one scientific study reconstruct a minimum eruption time of 3 hours in which an initial explosion raised a column of 23 km (75,459.3 ft) and deposited about 0.32 km3 of white pumicePumice
Pumice is a textural term for a volcanic rock that is a solidified frothy lava typically created when super-heated, highly pressurized rock is violently ejected from a volcano. It can be formed when lava and water are mixed. This unusual formation is due to the simultaneous actions of rapid...
("the white pumice phase"), while a second, more intense explosion raised a column of 31 km (101,706 ft) depositing 1.25 km3 of grey pumice ("the grey pumice phase"). These pumices appearing in Apulia
Apulia
Apulia is a region in Southern Italy bordering the Adriatic Sea in the east, the Ionian Sea to the southeast, and the Strait of Òtranto and Gulf of Taranto in the south. Its most southern portion, known as Salento peninsula, forms a high heel on the "boot" of Italy. The region comprises , and...
n pottery can be used to establish relative chronology of pottery phases.
A 2008 study of the lithofacies
Lithofacies
Lithofacies may refer to:* A mappable subdivision of a designated stratigraphic unit, distinguished from adjacent subdivisions on the basis of lithology; a facies characterized by particular lithologic features....
(deposits from the eruption) distinguishes three phases. Pyroclastic flow
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
s (PDC's) of Phases 1 and 2 were generated by "magmatic fragmentation" and had "small dispersal areas" mainly on the slopes of Vesuvius. Phase 3 was created by "phreatomagmatic
Phreatic
The term phreatic is used in Earth sciences to refer to matters relating to ground water below the water table . The term 'phreatic surface' indicates the location where the pore water pressure is under atmospheric conditions...
fragmentation," in which clastic fragments are driven by superheated steam from ground water mixed with the other gases released from the magma. The authors characterize Phase 3 as "the most voluminous and widespread in the whole of Somma-Vesuvius' eruptive history." Some facies a few cm thick were found 25 km (15.5 mi) from the source. The vent was 2 km (1.2 mi) west of today's center. About 50 cm (19.7 in) fell on Avellino.
Date of the eruption
The date of the Avellino Eruption remains to be determined with a precision greater than about 500 years within the framework of the Early/Middle Bronze AgeBronze Age
The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...
. A range of 2000 BC — 1500 BC includes the great majority of estimates. Ample opportunity to obtain Carbon-14 dates from charcoal and soil buried under the deposits has existed and still exists. Sporadic Carbon dating continues, with each scientist claiming to have obtained "the latest." Consistency with previous and subsequent work remains elusive. Since a real and very precise calendar date of the eruption must have existed, variation in estimations can only be the result of limitations to the carbon-dating method, which, given a plenitude of reliably emplaced samples, can only produce a date within a window of roughly 500 years in a maximum elapsed time of roughly 4000 years or 1/8 (12.5%).
According to Giardino, estimations fall into two ranges: 1880-1680 BC and 1684-1535 BC. He prefers the earlier, tagging it as "the end of the Early Bronze Age."
A study published in 1990 by Vogel and others suggested that the Avellino Eruption was responsible in part for the climatic disturbances of the 1620s BC
1620s BC
-Events and trends:* 1627 BC—Beginning of a period of cooling of the world climate lasting several years, recorded in tree-rings all over the world. It might have been caused by the Minoan eruption of Thera which according to the Parian Chronicle occurred in 1627, or the Avellino eruption of Mount...
. The latter were verified by "tree-ring series" and "ice-core layers." The authors had just obtained carbon dates of 3360±40 BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...
, or 1617-1703 calibrated BC. They were suggesting a coincidence of a number of eruptions, such as the Santorini
Santorini
Santorini , officially Thira , is an island located in the southern Aegean Sea, about southeast from Greece's mainland. It is the largest island of a small, circular archipelago which bears the same name and is the remnant of a volcanic caldera...
explosion, that destroyed Minoan
Minoan civilization
The Minoan civilization was a Bronze Age civilization that arose on the island of Crete and flourished from approximately the 27th century BC to the 15th century BC. It was rediscovered at the beginning of the 20th century through the work of the British archaeologist Arthur Evans...
civilization. The hypothesis remains unverifiable a generation later, due to the overall imprecision of the dates.
The Nola bronze-age village
The eruption destroyed several Bronze AgeBronze Age
The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...
settlements. The remarkably well-preserved remains of one were discovered in May 2001 at Croce del Papa
Nola-Croce del Papa
Nola-Croce del Papa was an early Bronze age village discovered in May 2001 in the Campania region near Nola, Italy. The settlement has been described as the "first Pompeii" by archaeologists.-Discovery:...
near Nola
Nola
Nola is a city and comune of Campania, southern Italy, in the province of Naples, situated in the plain between Mount Vesuvius and the Apennines...
by Italian archaeologists, with hut
Hut
Hut may refer to:*Hut , a small and crude shelter*Hans Hut , Anabaptist leader*Hut Records, an English audio records company*Sunglass Hut International, largest American retailer of sunglasses...
s, pot
Pot
Pot commonly refers to pottery, the ceramic ware made by pottersPot may also refer to:- Containers :* Plant pot or flower pot, a container in which plants are cultivated* Cooking pot, a stove-top cooking utensil* Chamber pot, a bedside urinal...
s, livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
and even the footprint
Footprint
Footprints are the impressions or images left behind by a person walking. Hoofprints and pawprints are those left by animals with hooves or paws rather than feet, while "shoeprints" is the specific term for prints made by shoes...
s of animals and people, as well as skeletons. The residents had hastily abandoned the village, leaving it to be buried under pumice
Pumice
Pumice is a textural term for a volcanic rock that is a solidified frothy lava typically created when super-heated, highly pressurized rock is violently ejected from a volcano. It can be formed when lava and water are mixed. This unusual formation is due to the simultaneous actions of rapid...
and ash in much the same way that Pompeii was later preserved.