The eruption of AD 79 and its impact on Pompeii and Herculaneum Flashcards
What occurred during the morning of the Mt Vesuvius eruption?
- earthquakes
- white smoke exiting from the volcano
- birds flee
What occurred during the afternoon of the Mt Vesuvius eruption?
- early afternoon earthquakes became stronger and pumice fell from sky knocking off tiles off roofs
- midday town was covered in as and huge grey clouds of smoke
- evening buildings are on fire and collapsing before the whole sky turns grey
What occurred during the late morning of the day after the Mt Vesuvius eruption?
- The town is completely buried
- The sky begins to clear
What occurred during the early morning of the day after the Mt Vesuvius eruption?
- some buildings were buried
- pyroclastic surges
- everything is covered in ash and the sky is completely grey
What is a pyroclastic surge?
a low-density, turbulent cloud of hot ash and drock that billows over the terrain, barely touching the ground. Up to speeds of 300km/h and with temperatures of more than 100*
What is pyroclastic flow?
a hotter, dryer and denser avalanche of ground-hugging molten rock, pumice and toxic gases that are heated to 400*, travelling at speeds of 20-50 km/h.
What is Tephra?
material of all types and sizes that is ejected into and deposited from the air
what type of explosion what Mt Vesuvius?
A plinian explosion
What settlements were completely burried?
Pomepii. Herculaneum, Stabiae, and Oplontis
How do we know what the eruption was like?
- Pliny the youngers letters
- human remains at both H and P
- compared findings of other eruptions
who reconstructed the eruption events and how many phases are there?
- vocalanologist Haraldur Sigurdsson
- 2 phases: Plinian and Nuee ardente
what happened in the Plinian Phase?
- Pumice and ash were expelled to form an eruption column reaching 33km above the volcano.
- occurred for about 18 hours as it was blown by wind onto nearby areas
(P for pumice)
What happened in the Nuree ardente phase?
- pyroclastic surge
- pyroclastic flow (not Pompeii)
what was the eruption at Stabaie like? and where is it from MV?
1
- ash and pumice covered the town, so heavy it covered doorways
- Dawn the 2nd day was as dark as night
- tremors that increased in frequency and strength
2
- 17km SE of MV
where is Herculaneum from MV?
7km west of MV between two streams
what was the eruption at Herculaneum like?
- did not experience ash and pumice but felt earthquakes and tremors
- pyroclastic surge 5 mins after column collapse
- buildings toppled, stoneworks moved
- waterfront boiled drastically
- people sheltering were killed by asphyxiation
how deep was Herculaneum buried?
buried under 23m of material
where is Pompeii in terms of MV?
9km east of MV
what was the eruption at Pompeii like?
- explosion may have been visible
- 12 hours of ash and pumice rain (people started to escape)
- if they reached Herculaneum gate, many would have died from asphyxiation
- temp of 400* and toxic gases
- toppled buildings and buried
how accurate is the timetable of the eruption?
- Sigurdsson matched results on stratigraphical deposits with Pliny the younger account
- times are expressed as estimates only
What were the causes of death at Pomepii?
- 394 found in pumice from building collapse or asphyxiation
- 653 found dead from thermal shock
Causes of death at Herculaneum?
- only 30 bodies were found in the city
- around 300 died at the boat house as a result of the intense heat or p. surges.
why did people at Herculaneum flee to the boathouse?
- a form of shelter
- tremors came before the eruption
- boats as a way to escape
what connection does Pliny the Younger have to MV?
- 17 years old staying with uncle nearby
- wrote a description of eruption to Tacitus 25 years after event
Why can Pliny the youngers letters be seen as questionable?
- wrote 25 years afterwards
- fail to mention date or year
- exaggerate the role of Pliny the elder
When is the traditional date of the eruption?
24th August AD 79
