Vesuvius Erupts in 79 AD

A re-enactment of Vesuvius erupting in 79AD

A re-enactment of Vesuvius erupting in 79AD

Vesuvius is currently the only active volcano in mainland Europe, and while the volcano has been dormant since 1944, the cataclysmic eruption that started on August 24, 79 AD reminds everyone of the real danger that Vesuvius poses. For 2 days the cities of Pompeii and Herculaneum in Italy were being hit by the most famous volcanic explosion of Vesuvius, but the dates in August that have been accepted for so long are now being challenged as incorrect.

Years worth of earthquakes led up to the eruption but as the people were unaware that earthquakes and volcanic activity was linked, the people remained in their homes as seismic activity is common in that region. Vesuvius erupts about every 40 years or so and before the eruption in 79 AD, it had been a longer dormant period causing people to move to the luring cities of Pompeii and Herculaneum without considering the risks of volcanic activity. The earthquakes should have been their first warning sign, but the first sign they received was the smoke cloud rising from Vesuvius, it was too late for most people to evacuate.

When the volcano started its eruption, the people would have first seen Vesuvius emit a large plume of smoke from its top. Next, it would have been absolutely necessary to seek shelter as the ash and pumice from the plume began to rain down on Pompeii. For the next 12 hours, burning embers as large as 3 inches in diameter, would have plummeted at such great speed that it would have caused extensive damage to anyone in the elements. Herculaneum was not effected by this first event due to a wind sweeping the debris toward Pompeii. This hot ash and pumice rain continued until the morning of the 25th, when pyroclastic flows from Vesuvius began as a result of the continuing earthquakes. A pyroclastic flow is a mixture of hot, dry rock fragments that travels along the ground, and hot, toxic gases moving above the ground, both at very high speeds. The gases reached both of the cities first, instantly suffocating everyone in what would have been the first surge. Multiple surges followed that decimated the land, even reshaped the coastline.

Pyroclastic flow from Vesuvius eruption

Pyroclastic flow from Vesuvius eruption

A firsthand account of Vesuvius’ eruption survived from Pliny the Younger, a Roman administrator and poet, who watched the event from the safety of the Bay of Naples. He wrote a description of the eruption to a historian friend named Tacitus 25 years after the eruption, giving the date as “nonum kal. Septembres” meaning nine days prior to the first day of September, which would be August 24 on the Roman calendar.

This date has recently been challenged according to artifacts found at the perfectly preserved sites in Pompeii and Herculaneum.

Freshly harvested pomegranates and walnuts were found within the preserved items. Pomegranates and walnuts are autumn fruits that were not harvested in the summer months, making it unlikely that they would be available in August. Other food items were also found, such as dried dates, prunes and figs, which were harvested in the summer and dried before they became rotten. Wine fermenting jars were also found buried in the ground. September is the earliest that grapes would have been harvested and in order for the wine fermenting jars to already be buried, the grapes would have to have been harvested already and then the jars would have had to stay above ground for at least 10 days prior to burying. This was the practice of the times in fermenting grapes into wine.

The citizens of Pompeii and Herculaneum were preserved with ash when the eruption occurred and have been found during several different excavations. More and more of these sites are being uncovered and unearthed as we learn more about the deadly volcanic eruption. Since the bodies are now exposed to the elements, casts of the bodies have been made to ensure we have these rare artifacts that show every detail of their bodies, including their clothing. What can be seen upon inspection is that the people living in these two cities were wearing layers of heavy, warm clothing, a strange sight at the height of summer. Experts have concluded that October is the more likely date since the people of Pompeii and Herculaneum were wearing clothes seen more so in the winter months.

Pliny wrote the date down when he described Vesuvius to Tacitus but Roman dates were often confused during the copying process, which lead some researchers to believe that Pliny actually wrote October, not August. Another manuscript, that exists in copy form as the original has not survived, gives the date as November for the eruption. Pliny also did not write to Tacitus until 25 years after Vesuvius erupted leaving some experts to believe that he could have remembered the date wrong after such a long period of time.

The last argument for the date being incorrect is that when Vesuvius erupted in 79 AD, the deposits from the pyroclastic flow were found in a southeasterly direction. Botanical evidence was gathered at Vesuvius for 8 different eruptions, along with the gathering of wind data of a period of 20 years. What was concluded was that the wind pattern during the 79 AD eruption was consistent with the changing of the seasons from summer to autumn.

Plaster casts of the people who died in Pompeii

Plaster casts of the people who died in Pompeii

Not everyone agrees that Vesuvius erupted in the late fall though, there are still those who believe August 24th is the day the sky darkened over Pompeii and Herculaneum. A food made from a fish found commonly in summer markets was found within the sites as well. The recipes for the dish state that the fish should sit no longer than a month, which would coincide with a late August, early September date since the fish were found in July and early August.

As far as the warmer clothes that were found on the bodies, it has been suggested that this was not due to the weather but to protect their bodies against the debris. Furthermore, roughly 350 species of summer pollen was found in Pompeii, pollen that would not exist in the autumn.

While the two dates, August 24 and October 24, are only two months apart from one another, it changes the way in which Vesuvius is understood. Researchers and scientists have not been able to agree on the dates, and may never unless irrefutable evidence is discovered. Although most experts now agree on October as the eruption of Vesuvius in 79 AD, some still hold true that Pliny’s account of the event is the fact that is undeniable.