Traditionally, 24-25th August is the date of the deadly Mount Vesuvius eruption of 79AD. One of the worst in European history, it buried the ancient cities of Pompeii, Oplontis and Stabiae and Herculaneum.
In 79 AD, Mount Vesuvius erupted, spewing a deadly cloud of super-heated tephra and gases to a height of 33 km. Molten rock, pulverised pumice and hot ash were ejected at 1.5 million tonnes per second.
The area is now a major tourist attraction and UNESCO World Heritage Site.
Small earthquakes were felt for four days before the Vesuvius eruption of 79 AD; but locals did not recognise the warnings. The inhabitants of the surrounding area were accustomed to minor earth tremors in the region. The writer Pliny the Younger wrote, they “were not particularly alarming because they are frequent in Campania”.
The eruption lasted for two days. The morning of the first day was perceived as normal by the only eyewitness to leave a surviving document, Pliny the Younger. He was 29 kilometres away at Misenum, on the other side of the Bay of Naples.
During the next two days, he did not have any opportunity to talk to people who had witnessed the eruption from Pompeii or Herculaneum (in fact, he never mentions Pompeii in his letter.
Around 1pm, Mount Vesuvius spewed a high-altitude column from which ash and pumice began to fall, blanketing the area. Rescues and escapes occurred during this time. At some time in the night or early the next day, pyroclastic flows in the close vicinity of the volcano began.
People as far away as Misenum fled for their lives.
The flows were rapid-moving and very hot, wholly or partly knocking down all structures in their path, incinerating or suffocating the remaining population and altering the landscape.
Pliny the Younger wrote an account of the eruption:
“broad flames shone out in several places from 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.”
The account of Pliny the Younger
The only surviving eyewitness account of the event consists of two letters by Pliny the Younger. He was 17 at the time of the eruption but wrote to the historian Tacitus some 25 years after the event.
Seeing the first volcanic activity from Misenum, Pliny the Elder (Pliny the Younger’s uncle) launched a rescue fleet and went to the rescue of a personal friend. His nephew declined to join the party. One of Pliny the Younger’s letters relates what he could discover from witnesses of his uncle’s experiences. In a second letter, he details his own observations after the departure of his uncle.
Pliny the Younger saw an extraordinarily dense cloud rising rapidly above the mountain:
“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.”
Date of the eruption
First-century Roman sources mention Vesuvius’s destructive eruption but not the day of the eruption.
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 Pliny the Younger’s letter.
In 1990 and 2001, archaeologists discovered more remnants of autumnal fruits (such as the pomegranate), victims dressed in heavy clothing, and large earthenware storage vessels laden with wine. The lattere discovery may show the eruption was after the year’s grape harvest and wine making.
In October 2018, Italian archaeologists uncovered a charcoal inscription dated October 17 (likely to be from 79 AD) which sets the earliest possible date for the eruption. A collaborative study in 2022 has determined a date of October 24-25.
Last eruption of Vesuvius
The last eruption of Vesuvius was on 18 March 1944 and went on for several days. It destroyed three villages nearby and about 80 planes belonging to the US Army Air Forces, which were based at an airfield close to Pompeii.