New research unveiled a detailed, minute-by-minute reconstruction of the catastrophic 32-hour eruption of Mount Vesuvius in 79 CE. According to a study published in the Journal of the Geological Society and reported by Science, volcanologists extended the chronology of the eruption from the previously estimated 19 hours to 32 hours.
The disaster began around noon on August 24 or October 24, 79 CE, when Mount Vesuvius, a 609-meter volcano located in the Bay of Naples, began to eject a cloud of rocky volcanic fragments and gas into the air, known as an eruption column.
At 1:00 p.m., Pliny the Younger, a 17-year-old Roman commander stationed at Misenum across the Bay of Naples, observed a cloud in the shape of an umbrella hovering over Mount Vesuvius, as described in his account. The ash cloud is estimated to have reached the stratosphere at a height of 34 kilometers. This towering, umbrella-shaped plume was characteristic of what is now known as a Plinian eruption, named after Pliny's detailed descriptions.
Starting at 2 p.m., Mount Vesuvius began to rain pieces of pumice—a porous volcanic rock formed when a gas-rich froth of glassy lava solidifies rapidly—that accumulated up to 2.7 meters thick, crushing buildings and residents in Pompeii, Herculaneum, and other nearby settlements. For the next 17 hours, the continuous fall of pumice stones caused many roofs to collapse, while people ran desperately to save their lives.
During a lull that followed the initial eruption, residents attempted to flee the doomed city, but many could not escape between 2:00 p.m. and 7:00 p.m. due to the dangers presented by the ongoing eruption. According to the new research, some residents might have survived had they been able to leave during this five-hour window.
Five hours after the initial eruption, at 7:06 p.m., the disaster intensified when Mount Vesuvius ejected the first pyroclastic flows—the deadly hot and rapidly moving flows of gas and volcanic particles, which vaporized residents and turned human tissue into glass in a process known as vitrification. These flows continued throughout the night and the next day, with intervals of about 80 minutes.
Approximately half of the victims of Pompeii were found in the streets, buried by the volcanic layer generated by the pyroclastic flows. The study estimates that Mount Vesuvius ejected nearly 8 cubic kilometers of debris, enough to bury all of Manhattan under 130 meters.
"It is not possible to survive such a phenomenon," said Claudio Scarpati, the head of the study, according to the journal Science.
The eruption came to an end at 8:05 p.m., leaving behind a trail of devastation, indicating that few had remained in the city when the eruption finally stopped. After the eruption, the bodies of the victims in Pompeii were famously preserved in a protective shell of ash before eventually decomposing.
Mount Vesuvius, located on the west coast of Italy just 9 kilometers from Naples—a city of 3 million inhabitants—is one of the most dangerous volcanoes in the world and is still active, posing a serious threat of eruption. The possibility of history repeating itself has to be taken very seriously, especially for Italians living in the Bay of Naples.
The findings from recent studies are expected to help in the preparation of emergency plans for a possible new eruption of Vesuvius.
The data was combined with the famous testimony of Pliny the Younger, who vividly described the eruption in a series of letters, suggesting that the eruption took the residents of Pompeii by surprise.
Volcanologists from the University of Naples Federico II mapped the deposits of volcanic materials over an area of 2,000 square kilometers around Vesuvius, measuring the distribution and volume of the volcanic layers. By examining the layers of ash, rock, and sediment that blanketed Pompeii, the authors of the new study pieced together the fluctuating nature of the eruption.
"This suggests that few of the residents of Pompeii, if any, were alive after the devastation of the morning," the researchers say.
Cataclysmic events like the eruption of Mount Vesuvius are now known as Plinian eruptions. Pyroclastic density currents are flowing surges of red-hot gas and debris that spread rapidly across the landscape surrounding a volcano, obliterating everything in their path.
At the time of the disaster, it was thought that Mount Vesuvius was inactive because it had not erupted in approximately 1,800 years, which meant that the locals were not prepared for the catastrophe.
The article was written with the assistance of a news analysis system.