Researchers Show How Mount Vesuvius Eruption Vaporized Blood and Exploded Skulls

Hundreds of people in the town of Herculaneum took cover from the eruption in boat-houses. Their bones tell a gruesome story.

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Oct 9 2018, 4:38pm

Herculaneum victims of Vesuvius. Image: Sally V

The eruption of Mount Vesuvius in 79 AD is seared into historical memory by the deadly carnage left by ash and lava that buried nearby settlements and their helpless residents. Now, research published in PLOS One takes the horror of that day to a literally blood-boiling, head-bursting new level.

Led by Pier Paolo Petrone, a biomedical scientist at the University of Naples, researchers studied over 100 skeletal remains from the estimated 300 victims who hid in boat-houses along the waterfront of Herculaneum, a town located 11 miles from Pompeii. The team concluded that these unfortunate people were hit with such intense temperatures that their blood vaporized, causing steam pressure to explode their skulls.

“Here we show for the first time convincing experimental evidence suggesting the rapid vaporization of body fluids and soft tissues of the 79 AD Herculaneum victims at death by exposure to extreme heat,” Petrone and his colleagues said in the paper. “We describe key evidence of body exposure to extreme heat provided by recurrent skull explosion, as detected by clear-cut fractures, whose margins are sharp like those seen in cremated bones.”

Fractured skulls. Image: P. Petrone et al

To reach this finding, the team examined skulls with advanced spectroscopic techniques in laboratory conditions. This process isolated iron and iron oxide residue inside the skulls, which may have been created by cranial bloodflows evaporating into steam. This, combined with previously observed skull fractures, suggests that some Herculaneum victims were killed by pent-up pressure in the interior of their heads.

These gruesome deaths were a result of a powerful pyroclastic surge, which is a molten blast of gas and rock, that swept over this waterfront refuge. The material is estimated to have been between 200 and 500°Celsius (roughly 400 and 900°Fahrenheit), and would have traveled at speeds of up to 180 miles per hour.

Image: P. Petrone et al

The only mercy is that the victims were killed before they could register what had hit them. The corpses seem to be “frozen,” according to Petrone and his team: “The lack of voluntary self-protective reaction or agony indicates that any vital activity had to stop within a time shorter than the conscious reaction time, a state known as fulminant shock.”

The researchers hope that reconstructing these horrible deaths will yield insights into the devastation of 79 AD. But they also emphasize that three million people still live in the danger zone of this notorious volcano, and warn of the “high-risk scenario” presented by another major eruption from Mount Vesuvius, even if people take cover in buildings.

Read More: Lava, Land, and Life Forms

“The evidence of thermal and mechanical effects recorded on people and structures from Vesuvius eruptions are key information that should be used by Civil Protection Agency [and other emergency services] to produce evacuation plans able to evacuate such a great number of residents, and not only the 700,000 people living in towns around Vesuvius, as established by the actual evacuation plan,” Petrone told me in an email.

“This has been and remains still a big unanswered query, even if in these last two decades many studies have been published about this argument, derived from field and laboratory investigations.”

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