The eruption of Vesuvius in 79 A.D. is known worldwide as one of the most devastating natural disasters in history.
The ‘catastrophic event that led to the destruction of Pompeii, Herculaneum, Oplonti and Stabia left an indelible mark. But also an immense heritage contained in the ancient cities buried by the violent eruption of 79 AD.
An eruption that occurred in several stages and was referred to by experts as the Plinian eruption. Referring to the letter written by Pliny the younger, addressed to his friend Tacitus, in which he describes in detail the eruption of Vesuvius in 79 AD. Observed by the latter in the villa of Miseno, 35 km from Pompeii.
The eruption of Vesuvius has been divided by experts into four different phases.
First phase of the eruption of Vesuvius in 79 AD.
The first phase of the eruption began several years earlier when Vesuvius showed the first signs of restlessness with small earthquakes.
The first seismic events began in 62 AD but were not associated with volcanic activity. Pompeiians, in fact, did not know they were at the foot of a Volcano, but thought Vesuvius was a mountain.
Before the eruption, in fact, the latter had a completely different appearance. It was tall and covered with dense vegetation, full of vines and wild animals. So its conformation had misled all the citizens living at its foot who had not realized the grave danger they were facing.
Despite the small earthquakes that plagued the Vesuvian cities, these tremors had not been interpreted as premonitions of an impending catastrophe. Probably if they had had more knowledge and awareness of the danger, they would have realized the disaster that was about to overwhelm them.
The second phase: the explosion of Vesuvius
The second phase, however, corresponds to the beginning of the eruption.
It was October 24, 79 AD, when Vesuvius exploded with unprecedented force. The volcanic plug obstructing the crater’s vent lifted and a column of gas, ash and lapilli rose into the sky, reaching frightening heights of up to 20 meters.
This is what is referred to by experts as a Plinian eruption. A ‘violent, frightening eruption, capable of rising tens of kilometers and erupting volcanic material even kilometers away with incredible force. And it is exactly the one described by Pliny the Younger in his letter.
Eruption continued with the fall of ash and lapilli, which invaded the streets and houses of the city of Pompeii, covering it under a thick layer of volcanic material more than 3 meters high.
The fall of pumice continued uninterruptedly until the following morning, when the pyroclastic flow arrived.
Third phase: the pyroclastic flow
The third phase coincided with the arrival of the fiery cloud and the heat wave of the pyroclastic flow.
After the fall of pumice, which came to a sudden halt, Pompeii was overwhelmed by the very powerful pyroclastic flow, a glowing cloud that reached temperatures of up to 400°, defined appunta by experts as pyroclastic flow.
This mass of gas, water vapor, ash and volcanic rocks moved rapidly toward the surrounding cities, burning and charring everything in its path. The heat wave associated with the burning cloud was extremely deadly, causing death and destruction on a vast scale.
Not only was Pompeii overwhelmed by the powerful pyroclastic flow, but also Herculaneum, which was initially unharmed by the falling lapilli due to its location on the slopes of Vesuvius.
The fourth phase: devastation
The inferno of fire lasted approximately four days, then everything came to a halt. This is the last phase that affected the cities of Pompeii, Herculaneum, Oplonti and Stabia.
The cities were completely buried under a mass of debris and abandoned for centuries until their archaeological discovery many centuries later.
Despite the devastation, immense tragedy and death to which the people of these ancient cities were subjected, the eruption of Vesuvius left an important legacy. For the volcanic ash preserved the buildings, streets and objects, offering valuable information today about aspects of Roman life at the time.
The same phases of the eruption can be observed in the visit to Pompeii, where there are, in some areas, the perfect stratification of the soil that demonstrates first the fall and accumulation of lapilli and then the arrival of the pyroclastic flow. On your visit to Pompeii, ask your guide to show you this particular aspect of the stratification of the soil; he will be able to guide you to discover this exceptional detail.
But the question on everyone’s mind is whether this huge tragedy could have been avoided.
Probably if Vesuvian citizens had had more knowledge about the true nature of the volcano, many would have been saved. But the streets, frescoes and houses of these ancient cities would have been equally overwhelmed and buried.
