What If Mount Vesuvius Erupted Again?

Looming over Naples, Italy, Mount Vesuvius is a monument to its own destructive past. It's also a sleeping giant that threatens the lives of hundreds of thousands of people who live and work around its base. When the volcano famously erupted in 79 CE, it utterly wiped out the towns of Pompeii and Herculaneum - as well as the populations that lived there. Writing about the event with both awe and horror, Pliny the Younger gave history the first-ever eye-witness account of a volcanic eruption.

Since 79 CE, the volcano has erupted 30 times. The most notable of these later eruptions occurred in 1631 and may have resulted in as many as 6,000 casualties. The most recent was in 1944, when Vesuvius launched debris into the air and claimed the lives of 26 people. However, none of those quakes came close to the power of the famous eruption, or the apocalyptic eruptions of the distant past.

The truly frightening thing about Vesuvius is that, based on geological research, it has reached its due date. When the volcano finally erupts, it may blow with the force of several hundred atomic detonations. So, what if Vesuvius erupted today? Here's a look at what that would mean for the people of Naples, Europe, and the world as a whole.


  • The Italian Government Would Implement Its Evacuation Plan

    The Italian Government Would Implement Its Evacuation Plan
    Photo: J. M. W. Turner / Wikimedia Commons / CC0 1.0

    If Mount Vesuvius rumbles to life once again, the Italian government - as well as the local governments in the Campania region - will put a plan into action that, in theory, could protect the residents of the towns and villages surrounding the volcano. The plan calls for the deployment of 500 buses and 220 trains to transport residents out of the major cities, and would require clockwork precision and flawless coordination among all local governments and regional directors.

    This level of coordination is a concern to Francesco Peduto, the president of Italy's National Council of Geology. He told The Independent, "Those who would have to put this plan into action - that is, the local civil protection from the different towns involved - don’t study and may not be in a position to put it into action."

    Without the plan, hundreds of thousands of people would be in jeopardy. The so-called "red zone" around Vesuvius, the region where devastation is unavoidable in an eruption, encompasses 25 towns and over 670,000 people. The less-impacted "yellow zone" accounts for an additional 63 towns and municipalities. Though farther away, this area would still be at risk from falling debris and ash.

  • Thousands Of Homes Built On The Slopes Of The Volcano Would Be Lost

    Not only have cities, towns, and small clusters of homes been built around the base of Vesuvius, thousands of structures have been built on the slopes of the volcano itself. To discourage people from living in such a dangerous area, the government has torn down these dwellings and set up a relocation fund to assist families to move out of the "red zone." This fund has largely failed to gain traction among residents, who like where they live.

    To further restrict people from purchasing land or building on the uppermost part of the volcano, the government officially designated 25,000 acres of the volcano a national park in 1995. Despite the dire warnings from officials, some 8,000 illegal structures have been found within the confines of the national park - including everything from homes to stores to restaurants.

    Efforts to tear these structures down have been met with stubborn resistance from many in the area who have no interest in leaving Vesuvius, even for their own protection. If the volcano erupted to its full potential, these structures would likely end up buried in magma and pyroclastic flow.

  • People Who Live In The 'Red Zone' Are Supposed To Find Refuge In Their Sister Cities

    People Who Live In The 'Red Zone' Are Supposed To Find Refuge In Their Sister Cities
    Photo: P. Gaultier / Wikimedia Commons / CC0 1.0

    If the evacuation plan is put into place, it would take two weeks to successfully evacuate the over 600,000 people living in the "red zones" around Vesuvius, according to Marco Di Lello, director of urban planning for the Campania region. This is one reason the government has been trying to encourage people to move to other areas. If the population decreased to 400,000, Di Lello says the evacuation would only take eight days. That still leaves the question: where would everyone go?

    Di Lello says plans have been put into place to evacuate residents into neighboring cities and designated sister cities in Italy. The hundreds of thousands of residents forced to flee would likely have to live as refugees in these cities, which would struggle to develop the infrastructure to house them for a period of time. Considering the risk to structures in the "red zones," the relocation could swiftly become permanent.

    In addition to using buses and trains to evacuate residents, it was decided that people living in the "red zones" - especially on the coast - would also be boarded onto boats. The evacuees would then be taken, temporarily, to the Italian island of Sardinia. "We will start a detailed census of our population first and then discuss in which town in Sardinia our citizens will be transferred, hoping that this day will never come," explained Pietro Amitrano, the mayor of Pompeii, in 2018.

  • The Evacuation Plan May Not Be Implemented

    There is a chance that, fearing a false alarm, those in charge of implementing the evacuation won't do it. There are many precursors to a volcanic eruption, including bradyseism activity (in which the ground swells due to magma filling underground chambers), geothermal activity, and tremors. All are legitimate warning signs of imminent eruption and could justify evacuation protocols.

    This was the case in 1984 when, following several seismic events in the nearby Campi Flegrei caldera (which, like Vesuvius, is part of the Campanian volcanic arc), officials evacuated 40,000 residents. However, no eruption occurred.

    Despite the "no eruption" scenario being better than the alternative, the disruption and chaos caused by the mandatory evacuation of hundreds of thousands of people for a false alarm could be very damaging to an official's public perception and popularity. "Imagine evacuating 580,000 people and nothing happens," Giovanni Macedonio, research director of Vesuvius Observatory, told USA Today. "Get it wrong, and it's the end of a career."

    Fearing for their reputations, civic leaders could delay an evacuation until it's too late.

  • The Volcano Could Release A Superheated Pyroclastic Surge

    The Volcano Could Release A Superheated Pyroclastic Surge
    Photo: SingALittle / Wikimedia Commons / CC0 1.0

    When people think of the destruction caused by a volcano, they probably imagine rolling waves of red hot magma burning the landscape and melting the homes and people in its path. However, most of the destruction caused by volcanoes comes from pyroclastic flows and surges.

    Unlike magma, which typically moves at a slower speed due to its viscosity, pyroclastic surges are ground-hugging clouds of superheated ash and toxic gases that can move at nearly 200 miles per hour - and instantly burn any living thing in their path.

    When Vesuvius erupted in 79 CE, scientists believe it produced six separate - and devastating - pyroclastic surges. "Temperatures outdoors - and indoors - rose up to 300°C [570°F] and more, enough to [end] hundreds of people in a fraction of a second," volcanologist Giuseppe Mastrolorenzo of the Italian National Institute for Geophysics and Volcanology explained to National Geographic News.

  • Superheated Ash Would Preserve Victims For Future Generations

    Superheated Ash Would Preserve Victims For Future Generations
    Photo: Vesuvius National Park / Wikimedia Commons / Public Domain

    Given the intense heat of pyroclastic surges, and the tens of thousands of people who live on or near the slopes of Mount Vesuvius's cone, there is a high likelihood that residents would be engulfed, flash-fried, and blanketed in solidifying ash - perfectly recording their final posture.

    Intense pyroclastic flows rolled over the city of Pompeii in 79 CE, slaying thousands and encasing their corpses. When archeologists began excavating the site in the 1800s, they found not only skeletons but also voids in the compacted, solidified ash surrounding them. By pouring plaster of Paris into the voids, researchers were able to recreate the victims' final poses.

    The plaster recreations give us a better idea of how Pompeiians expired, and even what their clothes looked like. The ash so perfectly imprinted around them that the plaster reveals some of their facial expressions at the time of their demise.