When Mount Vesuvius erupted in 79 AD, those living nearby had little to no chance of survival. The estimated 2,000 people who died would have passed away within minutes of the eruption – many of them probably not even knowing what happened.
According to a new study, it would have taken just 17 minutes for the exceptionally hot gas and ash released from the eruption to asphyxiate those living in Pompeii. While the inhabitants of Herculaneum wouldn’t have had any chance of survival, it is believed that those living in nearby Pompeii may have had more of a chance had the mountain’s pyroclastic flow lasted less than 17 minutes.
The pyroclastic flow, which is the cloud of gas, ash, and volcanic glass, would have been extremely hot with temperatures of more than 100 degrees Celsius (212 degrees Fahrenheit). It is believed that this cloud engulfed the city anywhere between 10 and 20 minutes (with an average of 17 minutes) following the volcanic eruption.
Based on the indentations of the bodies preserved in the ash, experts were able to figure out how they died after the volcano erupted. Many of the deceased in Pompeii either died of asphyxiation; sudden flash-heating where they wouldn’t have had time to suffocate; and being baked alive where they would have suffered for a longer amount of time. As a matter of fact, the eruption was so intense that it turned a man’s brain into glass.
When volcanoes erupt, fine ash that remains in the air can be harmful if inhaled by humans for any length of time. The researchers noted that humans can survive breathing in hot air with temperatures between 200 and 250 degrees Celsius (392 to 482 degrees Fahrenheit) for 2 to 5 minutes; however, when hot fine ash is mixed in with that hot air, it reduces that already limited time frame.
And since those living in Pompeii would have been exposed to it for approximately 17 minutes, they had no chance of survival. “This duration is quite long when compared to the couple of minutes considered as a survivable time for people engulfed in a PDC [pyroclastic density currents], even at low temperature,” the authors explained.
By gathering as much information as possible about pyroclastic flows, it could help those living close to active volcanoes in regards to evacuation processes and potential exposure to PDC.
The study was published in Scientific Reports where it can be read in full.