View source for Earth:Eruption of Mount Vesuvius in 79 AD

{{short description|Eruption of a stratovolcano in southern Italy during the Roman Empire}}
{{Infobox eruption
 | name = Eruption of Mount Vesuvius in 79 AD
 | date = {{circa|October}}, 79 AD
 | volcano = [[Earth:Mount Vesuvius|Mount Vesuvius]]
 | type = Plinian, [[Earth:Peléan eruption|Peléan]]
 | location = [[Earth:Campanian volcanic arc|Campania]], Italy
 | coordinates = {{coord|40|49|N|14|26|E|display=inline, title}}
 | VEI = 5
 | map = 
 | map_caption =
 | impact = Buried the Roman settlements of Pompeii, [[Religion:Herculaneum|Herculaneum]], Oplontis, and Stabiae.
 | image = Destruction of Pompeii and Herculaneum.jpg 
 | caption = ''The Destruction of Pompeii and Herculaneum'' ({{circa}}&nbsp;1821) by John Martin
|deaths=1,500–3,500, possibly up to 16,000<ref>{{cite web |title=3 – Vesuvius in 79 AD Ranks Way Down the List of History's Deadliest Eruptions |url=https://historycollection.com/7-things-didnt-know-tragic-town-pompeii-volcanic-eruption-destroyed/3/ |website=History Collection |date=August 7, 2017 |access-date=22 November 2020}}</ref>{{NoteTag|The number of confirmed deaths is currently 1,500, with that many bodies having been found thus far.}}}}

Of the many eruptions of [[Earth:Mount Vesuvius|Mount Vesuvius]], a major [[Earth:Stratovolcano|stratovolcano]] in southern Italy, the best-known (including in European history<ref>{{Cite journal |last=Martin |first=Stephanie C. |date=2020-05-01 |title=Past eruptions and future predictions: Analyzing ancient responses to Mount Vesuvius for use in modern risk management |url=https://www.sciencedirect.com/science/article/pii/S0377027319305384 |journal=Journal of Volcanology and Geothermal Research |language=en |volume=396 |pages=106851 |doi=10.1016/j.jvolgeores.2020.106851 |bibcode=2020JVGR..39606851M |s2cid=216194471 |issn=0377-0273}}</ref><ref>{{cite conference|first1=Sebastian|last1=Vogel|first2=Domenico|last2=Esposito|first3=Florian|last3=Seiler|first4=Michael|last4=Märker|title=Analysing the Rural Landscape around Pompeii before the Eruption of Somma-Vesuvius in AD 79|conference=Landscape Archaeology Conference (LAC 2012)|journal=ETopoi, Journal for Ancient Studies|volume=Special Volume 3|year=2012|pages=377–382|url=https://refubium.fu-berlin.de/bitstream/handle/fub188/18956/163.pdf}}</ref>) is its eruption in 79 AD, which was one of the deadliest.<ref name=BBCportents/>

In autumn of 79 AD, Mount Vesuvius violently spewed forth a [[Earth:Eruption column|cloud]] of super-heated tephra and [[Physics:Volcanic gas|gases]] to a height of {{convert|33|km|mi|abbr=on}}, ejecting [[Earth:Lava|molten rock]], pulverized [[Earth:Pumice|pumice]] and [[Earth:Volcanic ash|hot ash]] at 1.5&nbsp;million tons per second, ultimately releasing 100,000 times the [[Physics:Thermal energy|thermal energy]] of the atomic bombings of Hiroshima and Nagasaki.<ref name=sciencepompeii>{{cite magazine|url=http://www.time.com/time/magazine/article/0,9171,865531,00.html|archive-url=https://web.archive.org/web/20081214131422/http://www.time.com/time/magazine/article/0,9171,865531,00.html|url-status=dead|archive-date=December 14, 2008|title=Science: Man of Pompeii|magazine={{wipe|Time (magazine)}}|date=October 15, 1956|access-date=February 4, 2011}}</ref><ref>{{Cite web |last=Daley |first=Jason |date=10 October 2018 |title=Mount Vesuvius Boiled Its Victims' Blood and Caused Their Skulls to Explode |url=https://www.smithsonianmag.com/smart-news/mount-vesuvius-boiled-its-victims-blood-and-caused-their-skulls-explode-180970504/ |url-status=live |archive-url=https://web.archive.org/web/20181010213447/https://www.smithsonianmag.com/smart-news/mount-vesuvius-boiled-its-victims-blood-and-caused-their-skulls-explode-180970504/ |archive-date=10 October 2018 |access-date=15 August 2022 |website=Smithsonian Magazine}}</ref> The event gives its name to the Vesuvian type of volcanic eruption, characterised by columns of hot gases and ash reaching the [[Earth:Stratosphere|stratosphere]], although the event also included pyroclastic flows associated with Pelean eruptions.

The event destroyed several Roman towns and settlements in the area. Pompeii and [[Religion:Herculaneum|Herculaneum]], obliterated and buried underneath massive [[Earth:Pyroclastic surge|pyroclastic surge]]s and [[Earth:Tuff|ashfall deposits]], are the most famous examples.<ref name=BBCportents>{{cite web|title=Pompeii: Portents of Disaster |url=https://www.bbc.co.uk/history/ancient/romans/pompeii_portents_01.shtml|website=BBC History |author=Andrew Wallace-Hadrill|date=October 15, 2010|access-date=February 4, 2011}}</ref><ref name=sciencepompeii/> Archaeological excavations have revealed much of the towns and the lives of the inhabitants leading to the area becoming the Vesuvius National Park and a UNESCO World Heritage Site.

The total population of both cities was over 20,000.<ref>{{cite journal|title=Pompeii|first=Amedeo |last=Maiuri|journal=Scientific American|volume=198|number=4|date=April 1958|page=70|jstor=24940972 |bibcode=1958SciAm.198d..68M |doi=10.1038/scientificamerican0458-68}}</ref><ref>{{cite book|last=Maiuri |first=Amedeo|title=Herculaneum|location=Italy|publisher=Instituto Poligrafico Dello Stato, Libreria Dello Stato|year=1977|page=13}}</ref> The remains of over 1,500 people have been found at Pompeii and Herculaneum so far, although the total death toll from the eruption remains unknown.

==Precursor earthquakes==
[[Image:Karl Brullov - The Last Day of Pompeii - Google Art Project.jpg|thumb|''The Last Day of Pompeii''. Painting by Karl Brullov, 1830–1833]]
A major earthquake<ref>{{cite web|url=https://emidius.mi.ingv.it/CPTI04/down.php?file=CPTI04.pdf|title=Catalogo Parametrico dei Terrimoti Italiani|publisher=Istituto Nazionale di Geofisica e Vulcanologia|year=2004}}</ref> caused widespread destruction around the Bay of Naples, particularly to Pompeii, on February 5, 62 AD.<ref>{{Cite book |last=Martini |first=Kirk |title=Patterns of Reconstruction at Pompeii |date=September 1998 |publisher=Pompeii Forum Project, Institute for Advanced Technology in the Humanities (IATH), University of Virginia |chapter=Chapter 2: Identifying Potential Damage Events |chapter-url=http://www2.iath.virginia.edu/struct/pompeii/patterns/sec-02.html }}</ref> Some of the damage had still not been repaired when the volcano erupted in 79 AD.<ref name=VisitingPompeii>{{cite journal | url = http://www.archaeology.co.uk/cwa-2/world-features/visiting-pompeii.htm | last = Jones | first = Rick | title = Visiting Pompeii – AD 79 – Vesuvius explodes | journal = Current Archeology | date = 28 September 2007 | access-date = 20 June 2017 | archive-url = https://web.archive.org/web/20120308100010/http://www.archaeology.co.uk/cwa-2/world-features/visiting-pompeii.htm | archive-date = March 8, 2012 | url-status = dead }}</ref>

Another smaller earthquake took place in 64 AD; it was recorded by Suetonius in his biography of [[Biography:Nero|Nero]],<ref>{{cite book|chapter-url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Suetonius/12Caesars/Nero*.html#20 |title=The Life of Nero |last=Suetonius |first=C. Tranquillus |series= The Lives of the Caesars |chapter=20 |publisher=Loeb Classical Library, William P. Thayer |year=1914|orig-year=121}}</ref> and by Tacitus in ''Annales'' because it took place while Nero was in Naples performing for the first time in a public theater.<ref>{{cite book| first=Publius Cornelius | last=Tacitus | author-link=Tacitus | date=1864–1877 | orig-year=117 | title=The Annals | publisher=Modern Library, The Internet Sacred Text Archive | chapter=Book 15.22 | chapter-url=http://www.sacred-texts.com/cla/tac/a15020.htm}}</ref> Suetonius recorded that the emperor continued singing through the earthquake until he had finished his song, while Tacitus wrote that the theater collapsed shortly after being evacuated.

Minor earthquakes were reported in the four days before the 79 AD eruption, but the warnings were not recognized. The inhabitants of the area surrounding Mount Vesuvius had been accustomed to minor tremors in the region; [[Biography:Pliny the Younger|Pliny the Younger]] wrote that they "were not particularly alarming because they are frequent in Campania".<ref name="plinyletter"/>

==Nature of the eruption==
Reconstructions of the eruption and its effects vary considerably in the details but have the same overall features. The eruption lasted for two days.{{cn|date = January 2024}} [[Biography:Pliny the Younger|Pliny the Younger]], author of the only surviving written testimony, described the morning before the eruption as normal; however, he was staying at Misenum {{convert|29|km}} from the volcano across the Bay of Naples, and may not have noticed the early signs of the eruption.{{says who|date = January 2024}}{{cn|date = January 2024}} During the next two days, he did not have any opportunity to talk to people who had witnessed the eruption from Pompeii or Herculaneum,{{says who|date = January 2024}} and Pompeii is never mentioned in his letter.{{cn|date = January 2024}}

Around 1:00&nbsp;p.m., Mount Vesuvius erupted violently, spewing up a high-altitude column from which ash and pumice began to fall, blanketing the area.{{cn|date = January 2024}} Rescues and escapes occurred during this time.{{cn|date = January 2024}} At some time in the night or early the next day, pyroclastic flows in the close vicinity of the volcano began; lights seen on the mountain were interpreted as fires, and people as far away as Misenum fled for their lives.{{cn|date = January 2024}} The flows were rapid-moving, dense, and very hot, wholly or partly knocking down all structures in their path, incinerating or suffocating the remaining population and altering the landscape, including the coastline.{{cn|date = January 2024}} These were accompanied by additional tremors and a mild [[Tsunami|tsunami]] in the Bay of Naples.{{cn|date=July 2023}} One or more earthquakes at this time were strong enough to cause buildings to collapse at least in Pompeii killing the occupants.<ref>New victims from Pompeii emerge from the excavation of the House of the Chaste Lovers http://pompeiisites.org/en/comunicati/new-victims-from-pompeii-emerge-from-the-excavation-of-the-house-of-the-chaste-lovers/</ref>{{better source|date = January 2024}} By the evening of the second day, the eruption was over, leaving only haze in the atmosphere, screening sunlight.{{cn|date = January 2024}}

Pliny the Younger wrote:

<blockquote>broad flames shone out in several places from [[Earth:Mount Vesuvius|Mount Vesuvius]], which the darkness of the night contributed to render still brighter and clearer... It was now day everywhere else, but there a deeper darkness prevailed than in the thickest night.<ref name=PYLXV/>{{primary source inline|date = January 2024}}</blockquote>

=== Stratigraphic studies ===
[[File:Mt Vesuvius 79 AD eruption.svg|upright=1.35|right|thumb|Pompeii and Herculaneum, as well as other cities affected by the eruption of Mount Vesuvius. The black cloud represents the general distribution of ash, pumice and cinders. Modern coast lines are shown; Pliny the Younger was at Misenum.]]

Sigurðsson, Cashdollar, and Sparks undertook a detailed stratigraphic study of ash layers based on excavations and surveys, published in 1982. They concluded that the eruption unfolded in two phases, Vesuvian and Pelean, which alternated six times.<ref>{{cite journal|first1=Haraldur |last1=Sigurðsson |first2=Stanford |last2=Cashdollar |first3=R. Stephen J. |last3=Sparks |s2cid=11714919 |title=The Eruption of Vesuvius in A. D. 79: Reconstruction from Historical and Volcanological Evidence |journal=American Journal of Archaeology |volume=86 |date=January 1982|pages=39–51 |issue=1 |doi=10.2307/504292 |jstor=504292 }}</ref>

A first [[Earth:Plinian eruption|Plinian phase]] projected a column of volcanic debris and hot gases between {{convert|15|km|mi|0|abbr=on}} and {{convert|30|km|mi|abbr=on}} into the [[Earth:Stratosphere|stratosphere]]. This phase lasted 18 to 20 hours and spread pumice and ashes, forming a {{convert|2.8|m|ft|0|abbr=on}} layer to the south, towards Pompeii. An earthquake caused buildings in Pompeii to collapse at this time.<ref>New victims from Pompeii emerge from the excavation of the House of the Chaste Lovers http://pompeiisites.org/en/comunicati/new-victims-from-pompeii-emerge-from-the-excavation-of-the-house-of-the-chaste-lovers/</ref>

The following Pelean phase produced [[Earth:Pyroclastic surge|pyroclastic surge]]s of molten rock and hot gases that reached as far as Misenum, to the west. Concentrated to the south and southeast, two pyroclastic surges engulfed Pompeii with a {{convert|1.8|m|ft|0|adj=mid|-deep}} layer, burning and asphyxiating any living beings who had remained behind. [[Religion:Herculaneum|Herculaneum]], Pompeii, and Oplontis received the brunt of the surges and were buried in fine pyroclastic deposits, pulverized pumice and lava fragments up to {{convert|20|m|ft|-1|abbr=on}} deep. Surges 4 and 5 are believed to have destroyed and buried Pompeii.<ref>{{harvnb|Sigurðsson|Carey|2002|pp=42–43}}.</ref> Surges are identified in the deposits by dune and cross-bedding formations, which are not produced by fallout.

The eruption is considered primarily [[Earth:Phreatomagmatic eruption|phreatomagmatic]], i.e. a blast driven by energy from escaping steam produced by seawater seeping into the deep-seated faults and interacting with hot magma.

====Timing of explosions====
In an article published in 2002, Sigurðsson and Casey concluded that an early explosion produced a column of ash and pumice which rained on Pompeii to the southeast but not on Herculaneum, which was upwind.<ref>{{harvnb|Sigurðsson|2002}}</ref> Subsequently, the cloud collapsed as the gases densified and lost their capability to support their solid contents.

The authors suggest that the first ash falls are to be interpreted as early-morning, low-volume explosions not seen from Misenum, causing Rectina to send her messenger on a ride of several hours around the Bay of Naples, then passable, providing an answer to the paradox of how the messenger might miraculously appear at Pliny's villa so shortly after a distant eruption that would have prevented him.

===Magnetic studies===
[[File:Wnętrze krateru Wezuwiusz.jpg|thumb|upright|Inside the crater of Vesuvius]]
A 2006 study by Zanella, Gurioli, Pareschi, and Lanza used the magnetic characteristics of over 200&nbsp;samples of lithic, roof-tile, and plaster fragments collected from pyroclastic deposits in and around Pompeii to estimate the equilibrium temperatures of the {{nowrap|deposits.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=5}}.</ref>}} The deposits were placed by pyroclastic density currents (PDCs) resulting from the collapses of the Plinian column. The authors argue that fragments over {{convert|2|–|5|cm|abbr=on|sigfig=1}} were not in the current long enough to acquire its temperature, which would have been much higher. Therefore, they distinguish between the depositional temperatures, which they estimated, and the emplacement temperatures, which in some cases, based on the cooling characteristics of some types and fragment sizes of rocks they believed they also could estimate. The final figures are considered to be those of the rocks in the current just before deposition.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=6}}.</ref>

All crystal rock contains some iron or iron compounds, rendering it [[Physics:Ferromagnetic|ferromagnetic]], as do Roman roof tiles and plaster. These materials may acquire a residual field from several sources. When individual molecules, which are [[Physics:Magnetic dipole|magnetic dipole]]s, are held in alignment by being bound in a [[Earth:Crystal|crystal]]line structure, the small fields reinforce each other to form the rock's residual field.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=10}}.</ref> Heating the material adds [[Physics:Internal energy|internal energy]] to it. At the Curie temperature, the vibration of the molecules is sufficient to disrupt the alignment; the material loses its residual magnetism and assumes whatever [[Physics:Magnetic field|magnetic field]] might be applied to it only for the duration of the application. The authors term this phenomenon unblocking. Residual magnetism is considered to "block out" non-residual fields.

A [[Earth:Rock (geology)|rock]] is a mixture of minerals, each with its own Curie temperature; the authors, therefore, looked for a [[Spectrum|spectrum]] of temperatures rather than a single temperature. In the ideal sample, the PDC did not raise the temperature of the fragment beyond the highest blocking temperature. Some constituent materials retained the magnetism the Earth's field imposed when the item was formed. The temperature was raised above the lowest blocking temperature; therefore, some minerals on recooling acquired the magnetism of the Earth as it was in 79 AD. The broad field of the sample was the vector sum of the fields of the high-blocking material and the low-blocking material.

This type of sample made it possible to estimate the low unblocking temperature. Using special equipment that measured field direction and strength at various temperatures, the experimenters raised the temperature of the sample in increments of {{nowrap|{{convert|40|C-change|sigfig=1}}}} from {{convert|100|C|F|sigfig=2}} until it reached the low unblocking temperature.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=8}}.</ref> Deprived of one of its components, the overall field changed direction. A plot of direction at each increment identified the increment at which the sample's resultant magnetism had formed.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|pp=9–10}}.</ref> That was considered the equilibrium temperature of the deposit. Considering the data for all the surge deposits arrived at a surge deposit estimate. The authors discovered that the city of Pompeii was a relatively cool spot within a much hotter field, which they attributed to the interaction of the surge with the "fabric" of the city.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=1}}.</ref>

The investigators reconstruct the sequence of volcanic events as follows:

* On the first day of the eruption, a fall of white pumice containing clastic fragments of up to {{convert|3|cm|in|sigfig=1}} fell for several hours.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=3}}.</ref> It heated the roof tiles to {{convert|120|–|140|C|sigfig=2}}.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=12}}.</ref> This period would have been the last opportunity to escape. Subsequently, a second column deposited a grey pumice with clastics up to {{convert|10|cm|in|abbr=on|sigfig=1}}, temperature unsampled, but presumed to be higher, for 18 hours. These two falls were the Plinian phase. The collapse of the edges of these clouds generated the first dilute PDCs, which must have been devastating to Herculaneum, but did not enter Pompeii.
* Early in the second morning, the grey cloud began to collapse to a greater degree. Two major surges struck and destroyed Pompeii. Herculaneum and all its population no longer existed. The emplacement temperature range of the first surge was {{convert|180|–|220|C|sigfig=2}}, minimum temperatures; of the second, {{convert|220|–|260|C|sigfig=2}}. The depositional temperature of the first was {{convert|140|–|300|C|sigfig=2}}. Upstream and downstream of the flow it was {{convert|300|–|360|C|sigfig=2}}.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=13}}.</ref>

The variable temperature of the first surge was due to interaction with the buildings. Any population remaining in structural refuges could not have escaped, as gases of incinerating temperatures surrounded the city. The lowest temperatures were in rooms under collapsed roofs. These were as low as {{convert|100|C|sigfig=3}}, the boiling point of water.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=14}}.</ref> The authors suggest that elements of the bottom of the flow were decoupled from the main flow by topographic irregularities and made cooler by introducing turbulent ambient air. In the second surge, the irregularities were gone, and the city was as hot as the surrounding environment.

During the last surge, which was very dilute, an additional {{convert|1|metre|ft}} of deposits fell over the region.<ref>{{harvnb|Zanella|Gurioli|Pareschi|Lanza|2007|p=15}}.</ref>

==The Two Plinys==
[[Image:Pompeii&Vesuvius.JPG|thumb|Pompeii, with Vesuvius towering in the background]]

The only surviving eyewitness account of the event consists of two letters by [[Biography:Pliny the Younger|Pliny the Younger]], who was 17 at the time of the eruption,<ref>His 18th year by Roman reckoning, as they counted the first 12 months as the first year</ref> written to the historian Tacitus some 25 years after the event.<ref>Delphi Complete Works of Pliny the Younger, Volume 28 of Delphi Ancient Classics</ref><ref>{{cite book|author= C. Plinii Caecilii Secundi|title= Epistularum|chapter= Liber Sextus; 16 & 20|chapter-url=http://www.thelatinlibrary.com/pliny.ep6.html|publisher= The Latin Library}}</ref> Observing the first volcanic activity from Misenum across the Bay of Naples from the volcano, approximately {{convert|29|km}} away, Pliny the Elder (Pliny the Younger's uncle) launched a rescue fleet and went himself to the rescue of a personal friend. His nephew declined to join the party. One of the nephew's letters relates what he could discover from witnesses of his uncle's experiences.<ref name=Pliny1>{{cite book|author=Pliny the Younger|editor-first=Charles W.|editor-last=Eliot|year=1909|chapter=LXV. To Tacitus |series=The Harvard Classics|title=Vol. IX, Part 4: Letters|location=New York|publisher=Bartleby |chapter-url=http://www.bartleby.com/9/4/1065.html}}</ref> In a second letter, the younger Pliny details his own observations after the departure of his uncle.<ref name=Pliny2>{{cite book|author=Pliny the Younger|editor-first=Charles W.|editor-last=Eliot|year=1909|chapter=LXVI. To Cornelius Tacitus|series=The Harvard Classics |title=Vol. IX, Part 4: Letters|location=New York |publisher=Bartleby |chapter-url=http://www.bartleby.com/9/4/1066.html}}</ref>

=== Pliny the Younger ===
{{Further|Biography:Pliny the Younger}}
Pliny the Younger saw an extraordinarily dense cloud rising rapidly above the mountain:<ref name=Pliny1/>{{blockquote|the appearance of which I cannot give you a more exact description of than by likening it to that of a pine-tree, for it shot up to a great height in the form of a very tall trunk, which spread itself out at the top into a sort of branches. [...] it appeared sometimes bright and sometimes dark and spotted, according as it was either more or less impregnated with earth and cinders.}}

These events and a request by messenger for an evacuation by sea prompted the elder Pliny to order rescue operations in which he sailed away to participate. His nephew attempted to resume a normal life, continuing to study and bathe, but that night a tremor woke him and his mother, prompting them to abandon the house for the courtyard. At another tremor at dawn, the population abandoned the village. After a third tremor, "the sea seemed to roll back upon itself, and to be driven from its banks", which is evidence of a [[Tsunami|tsunami]]. There is, however, no evidence of extensive damage from wave action.

A black cloud obscured the early light through which shone flashes, which Pliny likens to sheet lightning, but more extensive. The cloud obscured Point Misenum near at hand and the island of Capraia (Capri) across the bay. Fearing for their lives, the population began calling each other and moving back from the coast along the road. Pliny's mother requested him to abandon her and save his own life, as she was too fleshy and aged to go further, but seizing her hand, he led her away as best he could. A rain of ash fell. Pliny needed to shake off the ash periodically to avoid being buried. Later that same day, the ash stopped falling, and the sun shone weakly through the cloud, encouraging Pliny and his mother to return home and wait for news of Pliny the Elder. The letter compares the ash to a blanket of snow. The earthquake and tsunami damage at that location were not severe enough to prevent continued use of the home.

=== Pliny the Elder ===

Pliny's uncle, Pliny the Elder, was in command of the Roman fleet at Misenum and had meanwhile decided to investigate the phenomenon at close hand in a light vessel. As the ship was preparing to leave the area, a messenger came from his friend Rectina (wife of Bassus<ref>{{cite web|title=Gallery: Pompeii|date=2019-07-03|access-date=October 18, 2020|url=https://kosmossociety.chs.harvard.edu/?p=21780}}</ref>) living on the coast near the foot of the volcano, explaining that her party could only get away by sea and asking for rescue.<ref name=PYLXV>{{cite book|author=Pliny the Younger|editor-first=Charles W. |editor-last=Eliot|year=1909|chapter=LXV. To Tacitus |title=Vol. IX, Part 4: Letters|series=The Harvard Classics|location=New York|publisher=Bartleby |chapter-url=http://www.bartleby.com/9/4/1065.html}}</ref> Pliny ordered the immediate launching of the fleet galleys to the evacuation of the coast. He continued in his light ship to the rescue of Rectina's party.<ref name=PYLXV/>

He set off across the bay but encountered thick showers of hot cinders, lumps of pumice, and pieces of rock in the shallows on the other side. Advised by the helmsman to turn back, he stated "Fortune favors the brave" and ordered him to continue to Stabiae (about {{convert|4.5|km|abbr=on|disp=or}} from Pompeii), where Pomponianus was.<ref name=PYLXV/> Pomponianus had already loaded a ship with possessions and was preparing to leave, but the same onshore wind that brought Pliny's ship to the location had prevented anyone from leaving.<ref name=PYLXV/>

Pliny and his party saw flames coming from several parts of the mountain, which Pliny and his friends attributed to burning villages. After staying overnight, the party was driven from the building by its violent shaking.<ref name=PYLXV/> They woke Pliny, who had been napping and snoring loudly. They elected to take to the fields with pillows tied to their heads to protect them from rockfall. They approached the beach again, but the wind had not changed. Pliny sat down on a sail spread for him and could not rise, even with assistance. His friends then departed, escaping ultimately by land.<ref>{{cite web |url=http://volcanology.geol.ucsb.edu/pliny.htm | author = Richard V. Fisher and volunteers | title = Derivation of the name "Plinian" | publisher = The Volcano Information Center, Department of Geological Sciences, [[Organization:University of California, Santa Barbara|University of California, Santa Barbara]] | access-date = May 15, 2010}}</ref> Very likely, he had collapsed and died, the most popular explanation for why his friends abandoned him, although Suetonius offers an alternative story of his ordering a slave to kill him to avoid the pain of incineration. How the slave would have escaped remains a mystery. There is no mention of such an event in his nephew's letters.

In the first letter to Tacitus, his nephew suggested that his death was due to the reaction of his weak lungs to a cloud of poisonous, sulphurous gas that wafted over the group.<ref name=PYLXV/> However, Stabiae was {{convert|16|km|abbr=on}} from the vent (roughly where the modern town of Castellammare di Stabia is situated), and his companions were apparently unaffected by the fumes, and so it is more likely that the corpulent Pliny died from some other cause, such as a stroke or heart attack.<ref>{{cite web |url=http://www.hort.purdue.edu/newcrop/history/lecture19/lec19.html |archive-url=https://web.archive.org/web/20120718082232/http://www.hort.purdue.edu/newcrop/history/lecture19/lec19.html |archive-date=July 18, 2012 |title=Lecture 19: Greek, Carthaginian, and Roman Agricultural Writers |website=History of Horticulture |year=2002 |first=Jules |last=Janick |publisher=Purdue University |access-date=May 15, 2010 |url-status=dead |df=mdy }}</ref> An [[Medicine:Asthma|asthma]]tic attack is also not out of the question. His body was found with no apparent injuries the next day once the plume had dispersed.{{Citation needed|date=December 2023}}

==Casualties from the eruption==
[[File:Pompeii Garden of the Fugitives 02.jpg|thumb|upright|left|The casts of some victims in the so-called "Garden of the Fugitives", Pompeii.]]

Apart from Pliny the Elder, the only other notable casualties of the eruption to be known by name were the Herodian princess Drusilla and her son Agrippa, who was born in her marriage with the procurator Antonius Felix.<ref>{{cite book |first=Flavius |last=Josephus |title=Jewish Antiquities |chapter=xx.7.2|title-link=Jewish Antiquities }} Also known to have been mentioned in a section now lost.</ref> It is also said that the poet Caesius Bassus died in the eruption.<ref>{{cite book |url=https://books.google.com/books?id=DFQlDQAAQBAJ&pg=PA252 |title=Playing the Farmer: Representations of Rural Life in Vergil's Georgics |first=Philip |last=Thibodeau |publisher=University of California Press |date=5 June 2011 |page=252 |isbn=9780520268326}}</ref>

By 2003, approximately 1,044&nbsp;casts made from impressions of bodies in the ash deposits had been recovered in and around Pompeii, with the scattered bones of another 100.<ref name="Episodes">{{cite journal | journal = Episodes | volume = 26 | date = September 2003 | title = The eruption of Vesuvius of 79 AD and its impact on human environment in Pompei | first1 = Lisetta | last1 = Giacomelli | first2 = Annamaria | last2 = Perrotta | first3 = Roberto | last3 = Scandone | first4 = Claudio | last4 = Scarpati | issue = 3 | pages = 235–238 | doi = 10.18814/epiiugs/2003/v26i3/014 | doi-access = free }}</ref> The remains of about 332 bodies have been found at Herculaneum (300 in arched vaults discovered in 1980).<ref>{{cite web | url = http://www.fieldmuseum.org/pompeii/herculaneum_2.asp | archive-url = https://web.archive.org/web/20090318012551/http://www.fieldmuseum.org/pompeii/herculaneum_2.asp | archive-date = March 18, 2009 | title = Pompeii, Stories from an eruption: Herculaneum | year = 2007 | website= The Field Museum of Natural History | location = Chicago | author = Soprintendenza archeologica di Pompei | access-date = May 12, 2010}}</ref> The total number of fatalities remains unknown.

[[Image:Ring Lady.JPG|upright|thumb|The skeleton called the "Ring Lady" unearthed in Herculaneum]]

Thirty-eight percent of the 1,044 were found in the ash fall deposits, the majority inside buildings.<ref name="Episodes" /> This differs from modern experience over the last 400 years when ashfalls have killed only around 4% of victims during explosive eruptions. This cohort was possibly sheltering in buildings when they were overcome. The remaining 62% of bodies found at Pompeii lay in the [[Earth:Pyroclastic surge|pyroclastic surge]] deposits, which probably killed them. It was initially believed that due to the state of the bodies found at Pompeii and the outline of clothes on the bodies, it was unlikely that high temperatures were a significant cause. Later studies indicated that during the fourth pyroclastic surge (the first surge to reach Pompeii), the temperature reached {{convert|300|C|F|abbr=on}}, which was enough to kill people in a fraction of a second.<ref>{{cite journal|title=Lethal Thermal Impact at Periphery of Pyroclastic Surges: Evidences at Pompeii|first1=Giuseppe|last1=Mastrolorenzo|first2=Pierpaolo|last2=Petrone|first3=Lucia|last3=Pappalardo|first4=Fabio M|last4=Guarino|journal=PLOS ONE|volume=5|issue=6|page=e11127|doi=10.1371/journal.pone.0011127|pmid=20559555|pmc=2886100|bibcode=2010PLoSO...511127M|year=2010|doi-access=free}}</ref> The contorted postures of bodies as if frozen in suspended action were not the effects of long agony, but of the [[Medicine:Cadaveric spasm|cadaveric spasm]], a consequence of heat shock on corpses.<ref>{{cite news| url = https://www.nationalgeographic.com/news/2010/11/pompeii-mount-vesuvius-science-died-instantly-heat-bodies/| archive-url = https://web.archive.org/web/20190814122015/https://www.nationalgeographic.com/news/2010/11/pompeii-mount-vesuvius-science-died-instantly-heat-bodies/| url-status = dead| archive-date = August 14, 2019| title = Pompeiians Flash-Heated to Death—'No Time to Suffocate{{'-}} | first = Maria Cristina | last = Valsecchi | newspaper = National Geographic News | date = November 2, 2010}}</ref> The heat was so intense that organs and blood were vaporised, and at least one victim's brain was [[Physics:Vitrification|vitrified]] by the temperature.<ref>{{cite journal|journal=The New England Journal of Medicine|volume=382|issue=4|pages=383–384|title=Heat-Induced Brain Vitrification from the Vesuvius Eruption in c.e. 79|doi=10.1056/NEJMc1909867|pmid=31971686|year=2020|last1=Petrone|first1=Pierpaolo|last2=Pucci|first2=Piero|last3=Niola|first3=Massimo|last4=Baxter|first4=Peter J.|last5=Fontanarosa|first5=Carolina|last6=Giordano|first6=Guido|last7=Graziano|first7=Vincenzo|last8=Sirano|first8=Francesco|last9=Amoresano|first9=Angela|display-authors=4|doi-access=free}}</ref>

Herculaneum, which was much closer to the crater, was saved from tephra falls by the wind direction but was buried under {{convert|23|m}} of material deposited by pyroclastic surges. It is likely that most, or all, of the known victims in this town, were killed by the surges, particularly given evidence of high temperatures found on the skeletons of the victims found in the arched vaults on the seashore and the existence of carbonised wood in many of the buildings. These people were concentrated in the vaults at a density as high as three per square metre and were all caught by the first surge, dying of thermal shock and partly carbonised by later and hotter surges. The vaults were most likely boathouses, as the crossbeams overhead were probably for the suspension of boats used for the earlier escape of some of the population. As only {{convert|85|m|ft}} of the coast have been excavated, more casualties may be waiting to be unearthed.

==Date of the eruption==

Vesuvius and its destructive eruption are mentioned in first-century Roman sources, but not the day of the eruption. For example, Josephus in his ''Antiquities of the Jews'' mentions that the eruption occurred "in the days of Titus Caesar."<ref name="Josephus">{{cite book |last1=Josephus |editor1-last=Whitson |editor1-first=W. |title=Antiquities of the Jews |publisher=Tufts University Perseus archive |url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0146%3Abook%3D20%3Asection%3D141}}</ref> Suetonius, a second-century historian, in his ''Life of Titus'' simply says that, "There were some dreadful disasters during his reign, such as the eruption of Mount Vesuvius in Campania."<ref name="Suetonius">{{cite book |last1=Suetonius |title=The Lives of the Twelve Caesars |url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Suetonius/12Caesars/Titus*.html |website=Penelope |publisher=University of Chicago |date=1914}}</ref>

Writing well over a century after the actual event, Roman historian Cassius Dio (as translated in the Loeb Classical Library 1925 edition) wrote that, "In Campania remarkable and frightful occurrences took place; for a great fire suddenly flared up at the very end of the summer."<ref name="Dio-section21">{{cite book |last1=Dio |title=Roman History, Book LXVI, section 21 |url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Cassius_Dio/66*.html |website=Penelope |publisher=University of Chicago |date=1925}}</ref>

For more than five centuries, until approximately 2018, articles about the eruption of Vesuvius typically stated that the eruption began on August 24 of 79 AD. This date came from a 1508 printed copy of a letter addressed by [[Biography:Pliny the Younger|Pliny the Younger]] to the Roman historian Tacitus, originally written some 25 years after the event.<ref>Delphi Complete Works of Pliny the Younger, 2014, Volume 28 of Delphi Ancient Classics</ref><ref name="plinyletter">{{cite book |last1=Pliny the Younger |title=Letters 6.16 and 6.20 |publisher=University of Arizona |edition=Penguin, translated by B. Radice, notes by A. Futrell |url=http://www.u.arizona.edu/~afutrell/404b/web%20rdgs/pliny%20on%20vesuvius.htm}}</ref> Pliny was a witness to the eruption and provided the only known eyewitness account. Over fourteen centuries of manuscript hand-copying up to the 1508 printing of his letters, the date given in Pliny's original letter may have been corrupted. Manuscript experts believe that the date originally given by Pliny was one of August 24, October 30, November 1, or November 23.<ref name="berrypompei">{{cite book |last1=Berry |first1=Joanne |title=The Complete Pompeii |date=2013 |publisher=Thames & Hudson Ltd. |location=London |isbn=978-0500290927 |page=20}}</ref> This odd scattered set of dates is due to the Romans' convention for describing calendar dates. The large majority of extant medieval manuscript copies – there are no surviving Roman copies – indicate a date corresponding to August 24. Since the discovery of the cities, this was accepted by most scholars and by nearly all books written about Pompeii and Herculaneum for the general public.

Since at least the late 18th century, a minority among archaeologists and other scientists have suggested that the eruption began ''after'' August 24, during the autumn, perhaps in October or November. In 1797 the researcher Carlo Rosini reported that excavations at Pompeii and [[Religion:Herculaneum|Herculaneum]] had uncovered traces of fruits and braziers indicative of autumn, not the summer.

More recently, in 1990 and 2001, archaeologists discovered more remnants of autumnal fruits (such as the pomegranate), the remains of victims of the eruption in heavy clothing, and large earthenware storage vessels laden with wine (at the time of their burial by Vesuvius). The wine-related discovery suggests that the eruption might have happened after the grape harvest.<ref name="journalvolcanology">{{cite journal |last= Rolandi |first= G. |author2= Paone, A. |author3= De Lascio, M. |author4= Stefani, G. |date= January 2008 |title= The 79 AD eruption of Somma: the relationship between the date of the eruption and the southeast tephra dispersion |journal= Journal of Volcanology and Geothermal Research |volume= 169 |issue= 1 |pages= 87–98 |doi= 10.1016/j.jvolgeores.2007.08.020 |bibcode= 2008JVGR..169...87R}}</ref>

In 2007, a study of prevailing winds in Campania showed that the southeasterly debris pattern of the first-century eruption is quite consistent with an autumn event and inconsistent with an August date. During June, July, and August, the prevailing winds flow to the west – an arc between the southwest and northwest – virtually all the time.<ref name=journalvolcanology />

As [[Biography:Titus#Challenges|Emperor Titus]] of the Flavian dynasty (reigning June 24, 79 to September 13, 81) garnered victories on the battlefield (including his capture of the Temple of Jerusalem) and other honors, his administration issued coins enumerating his ever-growing accolades. Given the limited space on each coin, his achievements were stamped on the coins using an arcane encoding. Two of these coins, from early in Titus' reign, were found in a hoard recovered at Pompeii's House of the Golden Bracelet. Although the coins' minting dates are somewhat in dispute,<ref name=journalvolcanology /> a [[Finance:Numismatics|numismatic]] expert at the British Museum, Richard Abdy, concluded that the latest coin in the hoard was minted on or after June 24 (the first date of Titus' reign) and before September 1 of 79 AD. Abdy states that it is "remarkable that both coins will have taken just two months after minting to enter circulation and reach Pompeii before the disaster."<ref name="Abdy">{{cite journal |last1=Abdy |first1=Richard |title=The Last Coin in Pompeii: A Re-evaluation of the Coin Hoard from the House of the Golden Bracelet |journal=The Numismatic Chronicle |date=2013 |volume=173 |pages=79–83 |jstor=43859727 }}</ref>

In October 2018, Italian archaeologists uncovered a charcoal inscription reading "the 16th day before the calends of November," dated October 17 (of 79 AD as it was unlikely to have been a year old)<ref>{{Cite news|url=https://www.bbc.co.uk/news/world-europe-45874858|title=Pompeii's destruction date could be wrong|date=October 16, 2018|newspaper=BBC News}}</ref> which sets the earliest possible date for the eruption.<ref>{{cite web|url=https://phys.org/news/2018-10-pompeii-evidence-rewrites-vesuvius-eruption.html|title=New Pompeii evidence rewrites Vesuvius eruption history|publisher=Phys.org|date=October 16, 2018}}</ref><ref>{{cite news|title=Archaeological find changes date of Pompeii's destruction|url=https://www.theguardian.com/world/2018/oct/16/archeological-find-changes-date-of-pompeiis-destruction|newspaper=The Guardian|date=16 Oct 2018}}</ref> A collaborative study in 2022 has determined a date of October 24–25.<ref>{{cite journal|first1=DM|last1=Doronzo|first2=MA|last2=Di Vito|first3=I|last3=Arienzo|first4=M|last4=Bini|display-authors=et al.|title=The 79 CE eruption of Vesuvius: A lesson from the past and the need of a multidisciplinary approach for developments in volcanology|journal=Earth-Science Reviews|volume=231|year=2022|page=104072|doi=10.1016/j.earscirev.2022.104072|bibcode=2022ESRv..23104072D |s2cid=249349095 |doi-access=free}}</ref>

==See also==
* Buildings at Pompeii, including
** Villa Boscoreale
** Villa Poppaea
* "Pompeii" (song), a 2013 song by Bastille inspired by the eruption of Mount Vesuvius
* Villa of Agrippa Postumus

==Notes==
{{reflist|group=note}}

==References==
{{reflist|colwidth=33em}}

==Bibliography==
* {{Cite book |last=Sigurðsson |first=Haraldur |title=The Natural History of Pompeii |editor-first=Wilhelmina Mary Feemster |editor-last=Jashemski |editor2-first=Frederick Gustav |editor2-last=Meyer |contribution=Mount Vesuvius Before the Disaster |location=Cambridge, UK |publisher=The Press Syndicate of the University of Cambridge |year=2002 |pages=29–36}}
* {{Cite book | last1=Sigurðsson | first1=Haraldur | first2=Steven | last2=Carey| title=The Natural History of Pompeii | editor-first=Wilhelmina Mary Feemster | editor-last=Jashemski | editor2-first=Frederick Gustav | editor2-last=Meyer | contribution=The Eruption of Vesuvius in AD 79 | location=Cambridge UK | publisher=The Press Syndicate of the University of Cambridge | year=2002 | pages=37–64}}
* {{cite journal | first1=E. | last1=Zanella | first2=L. | last2=Gurioli | first3=M.T. | last3=Pareschi | first4=R. | last4=Lanza | title= Influences of Urban Fabric on Pyroclastic Density Currents at Pompeii (Italy): Part II: Temperature of the Deposits and Hazard Implications | journal=Journal of Geophysical Research | year=2007 |url=http://www.earth-prints.org/bitstream/2122/2370/1/1245.pdf | volume=112 | issue=112 | pages=B05214 | doi=10.1029/2006JB004775 | bibcode=2007JGRB..112.5214Z }}

==External links==
* {{cite web |url=https://sites.google.com/site/ad79eruption/ |website=AD79 Destruction and Rediscovery |title=Home}} Information on the eruption, the locations destroyed, and subsequent rediscovery.
* {{YouTube|id=dY_3ggKg0Bc|title=A Day in Pompeii - Full-length animation}} by ZERO ONE and the Melbourne Museum — animation demonstrating what it would have looked like to see the eruption's effects on the city.


{{DEFAULTSORT:Vesuvius, Mount}}
[[Category:Plinian eruptions]]
[[Category:Peléan eruptions]]

{{Sourceattribution|Eruption of Mount Vesuvius in 79 AD}}