THE ERUPTION
At the time of the eruption of Mount Vesuvius in 79 AD, the Romans were caught completely unprepared. This is evident through the eye-witness account of Pliny the Younger, who recorded the event and other's reactions in great detail. From Pliny's first letter it is obvious that nobody knew of the approaching eruption, not even the educated Romans. For example, Pliny the Elder was an esteemed and knowledgeable member of society, and his first reaction to the event was to get closer. Alarm would not have been the response for many Romans, as many stayed in their houses hoping to wait it out. Pliny the Elder and his associates seemed to have no idea of the catastrophic event that was to take place.
Scientists today know that there were may warning signs prior to the eruption. This includes the major earthquake of 63 AD, and many seismic shocks afterwards, although nobody related these tremors to volcanic activity. Research shows that the longer the waiting period for Vesuvius, the larger the eruption will be. Before the eruption of 79 AD, Vesuvius had had a particularly long period where it lay dormant, which evidently resulted in a very destructive event.
The first century Romans seemed unconcerned by these earthquakes, and there is evidence that they had a constant cycle of repair work after each tremor. For example, buildings have been found with layers of plaster on them, and a trench was dug in the middle of the street, suggesting the Romans water supply had been cut off and they were using an alternative method.
This explains why many inhabitants of Pompeii and Herculaneum decided against fleeing. They were accustomed to waiting out the earthquakes and then persistently repairing any damage inflicted upon their town. The day of the eruption, 24th of August, 79 AD would have begun as normal. The population would have gone about their business as usual, whether it was work, baths, or shopping at the forum, all the while blissfully unaware that Vesuvius was about to erupt.
The eruption lasted for over 24 hours. Firstly, in the morning, small clouds were seen coming from Vesuvius. There had been earthquakes for many days before this, but the Romans were not alarmed. This continued until roughly 1pm, when Vesuvius suddenly erupted, spewing out a tall cloud of rock and gas, shaped like a pine tree, into the sky. This cloud rises up to 14km high in 30 minutes and spreads southwards to cause darkness in Pompeii.
As the cloud rises higher into the sky in the afternoon, the superheated gas and rock cool and harden to form pumice stones. These stones rain down on Pompeii and block any rivers and ports, making ships unable to sail. The pumice gradually gets heavier and the eruption escalates, and the stones ash gather on the street and rooftops. The weight of this causes the roofs to collapse. The cloud is now over 20km high and the darkness is only interrupted by lightning and fire flashes.
In the early hours of 25th August 79 AD mudflows from the volcano spill into Herculaneum. Ash and pumice continue to fall in Pompeii and rises to the height of the second storeys of buildings. Many people are suffocated, trapped or choked by this overflow of volcanic debris. As morning approaches the cloud continues to climb to over 30km high. By now it is too heavy to support its own weight and collapses, resulting in the first pyroclastic surge. Hot gas and rocks reach Herculaneum instantly killing anybody still in the city. The earthquakes continue and a second, hotter pyroclastic surge covers Herculaneum, burying it even deeper. The falling of debris eases in Pompeii and many spill onto the streets trying to escape, but the air is heavy with ash and it is hard to breathe, and the streets are covered in stone and ash.
At around 6:30am the third pyroclastic surge is unleashed. It reaches Pompeii but is held back by a wall. More surges reach these walls and sweep over the top, killing anyone left in Pompeii, and burying the city. By late morning the most destructive surge yet has hit Pompeii and ruined many of the structures in the town. Towns around the volcano are not hit by any surges but are surrounded by a cloud of ash. This is how Pliny the Elder died, as Pliny the Younger describes in his letter.
The eruption of 79AD was so powerful that Mount Vesuvius' summit collapses leaving a gigantic crater. The towns of Pompeii and Herculaneum had been almost completely buried, and would not be unearthed until centuries later.
Scientists today know that there were may warning signs prior to the eruption. This includes the major earthquake of 63 AD, and many seismic shocks afterwards, although nobody related these tremors to volcanic activity. Research shows that the longer the waiting period for Vesuvius, the larger the eruption will be. Before the eruption of 79 AD, Vesuvius had had a particularly long period where it lay dormant, which evidently resulted in a very destructive event.
The first century Romans seemed unconcerned by these earthquakes, and there is evidence that they had a constant cycle of repair work after each tremor. For example, buildings have been found with layers of plaster on them, and a trench was dug in the middle of the street, suggesting the Romans water supply had been cut off and they were using an alternative method.
This explains why many inhabitants of Pompeii and Herculaneum decided against fleeing. They were accustomed to waiting out the earthquakes and then persistently repairing any damage inflicted upon their town. The day of the eruption, 24th of August, 79 AD would have begun as normal. The population would have gone about their business as usual, whether it was work, baths, or shopping at the forum, all the while blissfully unaware that Vesuvius was about to erupt.
The eruption lasted for over 24 hours. Firstly, in the morning, small clouds were seen coming from Vesuvius. There had been earthquakes for many days before this, but the Romans were not alarmed. This continued until roughly 1pm, when Vesuvius suddenly erupted, spewing out a tall cloud of rock and gas, shaped like a pine tree, into the sky. This cloud rises up to 14km high in 30 minutes and spreads southwards to cause darkness in Pompeii.
As the cloud rises higher into the sky in the afternoon, the superheated gas and rock cool and harden to form pumice stones. These stones rain down on Pompeii and block any rivers and ports, making ships unable to sail. The pumice gradually gets heavier and the eruption escalates, and the stones ash gather on the street and rooftops. The weight of this causes the roofs to collapse. The cloud is now over 20km high and the darkness is only interrupted by lightning and fire flashes.
In the early hours of 25th August 79 AD mudflows from the volcano spill into Herculaneum. Ash and pumice continue to fall in Pompeii and rises to the height of the second storeys of buildings. Many people are suffocated, trapped or choked by this overflow of volcanic debris. As morning approaches the cloud continues to climb to over 30km high. By now it is too heavy to support its own weight and collapses, resulting in the first pyroclastic surge. Hot gas and rocks reach Herculaneum instantly killing anybody still in the city. The earthquakes continue and a second, hotter pyroclastic surge covers Herculaneum, burying it even deeper. The falling of debris eases in Pompeii and many spill onto the streets trying to escape, but the air is heavy with ash and it is hard to breathe, and the streets are covered in stone and ash.
At around 6:30am the third pyroclastic surge is unleashed. It reaches Pompeii but is held back by a wall. More surges reach these walls and sweep over the top, killing anyone left in Pompeii, and burying the city. By late morning the most destructive surge yet has hit Pompeii and ruined many of the structures in the town. Towns around the volcano are not hit by any surges but are surrounded by a cloud of ash. This is how Pliny the Elder died, as Pliny the Younger describes in his letter.
The eruption of 79AD was so powerful that Mount Vesuvius' summit collapses leaving a gigantic crater. The towns of Pompeii and Herculaneum had been almost completely buried, and would not be unearthed until centuries later.
SIGNIFICANCE
The eruption of Mount Vesuvius is a significant event in history as it preserved the towns of Pompeii and Herculaneum to be discovered centuries later. The cities give a unique view of the way people lived at the time, and even who they were, how they thought and what they enjoyed. This is evident through houses, objects they tried to save at the time of the eruption, how their houses were decorated and what type of recreational buildings existed. This depth of understanding we have today would not be obtainable if it weren't for the eruption.