Study shows people died from body fluid vaporization due to pyroclastic flows from Vesuvius

October 10, 2018 by Bob Yirka, Phys.org report
Thermal effects in human victims' skeletons. A. Skull of an older-aged adult male showing a dark stained and cracked parietal bone (ind. 11, chamber 12). B. Skullcap affected by a “stellate” fracture consisting of several cracks which radiate from a common center, characterized by charred outer margins (adult male, ind. 31, chamber 10). C. Exploded skull showing a partly dark stained inner table (right side, adult male, ind. 6, chamber 12); charring of the fractured margins is evident (white arrows) (bar scale 10 cm). The skull of this victim was lying in the ash bed on its left side. Credit: PLOS ONE (2018). DOI: 10.1371/journal.pone.0203210

A team of researchers at the Federico II University Hospital in Italy has found evidence that suggests many people living in Herculaneum during the 79 AD eruption of Mt. Vesuvius were killed by the extreme heat characteristic of pyroclastic flows. In their paper published on the open access site PLOS ONE, the group describes telltale signs of heat damage they found in the remains of people living in the ancient Roman city at the time.

Most people learned in grade school that Mt. Vesuvius erupted back in 79 AD and covered cities such as Pompei in ash. So sudden was the disaster that many people were killed and buried in ash, leaving their "frozen" remains to be discovered by archaeologists approximately 1700 years later. Extensive research has shown that most of the victims in Pompei died from injuries or suffocation due to the thick ash. But this was not the fate of many people living in the nearby city of Herculaneum. The researchers with this new effort have found that many of them were killed by the extreme heat of .

Pyroclastic flows are flows composed of gas and volcanic material—prior research has shown that they can flow downhill away from an eruption at speeds of up to 450 mph—and temperatures are as hot as 1000 degrees C. When a person is overcome by such a flow, the result is instant death. The researchers found evidence in the remains of many people who had sought refuge in a boathouse near the sea in Herculaneum. The team began their investigation after learning of reports of evidence of people dying from thermal shock.

Upon taking a closer look at some of the remains, the researchers found red and black on parts of some of the bones. Prior research suggested that such residue typically occurs when bones are burned in the vicinity of coins or other metal objects—the residue typically consists of iron particles. Prior research has also shown that such residues can also be caused by blood being boiled away leaving behind suspended iron. Study of the residue showed that it was iron, though the researchers could not say for certain if it came from blood or metal objects. The researchers also found of burst skulls, likely due to vaporizing brain matter.

Red and black mineral incrustations detected in the victims' skulls. A. Child's skull showing a round area of thick red mineral residues encrusting the right parietal bone (ind. 18, chamber 12); A1. Inner bone surface of parietal fragments encrusted by red mineral residues (sporadic skull fragments, adult, chamber 10); B. Skull showing dark staining and black residues encrusting (white arrow) the parietal and temporal bones (B1) (adult male, ind. 31, chamber 10); C. Skullcap of a young individual displaying spotted dark stained areas and charred open sutures (black arrows) (ind. 29, chamber 12). The intracranial cavity (C1) shows a clear boundary (black and white arrows) between an inner table of unchanged color (a) next to a black stained one (b) (scale bars in cm). Credit: PLOS ONE (2018). DOI: 10.1371/journal.pone.0203210

Explore further: Fuego volcano—the deadly pyroclastic flows that have killed dozens in Guatemala

More information: Pierpaolo Petrone et al. A hypothesis of sudden body fluid vaporization in the 79 AD victims of Vesuvius, PLOS ONE (2018). DOI: 10.1371/journal.pone.0203210

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Burn one
5 / 5 (3) Oct 10, 2018
This study really blew my mind.
antialias_physorg
5 / 5 (7) Oct 10, 2018
and temperatures are as hot as 1000 degrees C. When a person is overcome by such a flow, the result is instant death.

I think that statement was a bit superfluous. It's not like: "being enveloped in 1000°C clouds of toxic fumes? I would have thought that would induce a mild and lingering headache after 5 minutes of exposure. Tops."

That said: "Body fluid vaporization" sounds like a gruesome (but thankfully instant) way to go.
carbon_unit
5 / 5 (5) Oct 10, 2018
Hopefully the victims were rendered unconscious well before their brains exploded, etc.
(shudders)

There probably aren't too many places where one can take shelter from the immediate effects of a pyroclastic flow. Even if one does find such a place (deep basement under heavy masonry or a cave?), how long would one have to hold out before the heat and gasses dissipated. I can envision that many a hidy-hole would be simply places where one would be asphyxiated and/or slow cooked because the effects lingered too long.
antialias_physorg
5 / 5 (3) Oct 12, 2018
There probably aren't too many places where one can take shelter from the immediate effects of a pyroclastic flow.

Herculaneum is roughly 10km away from Mt. Vesuvius. At up to 450mph speeds for pyroclastic flow they would have had less than a minute to get to a 'safe space' - and that if they had reacted instantly.
(The natural reaction in case of an Earthquake - which certainly was part and parcel of an eruption - is to run outside)
antigoracle
not rated yet Oct 13, 2018
That body fluid vaporization was preceded by the body fluid excretion.
Whydening Gyre
5 / 5 (1) Oct 13, 2018
"Study shows people died from body fluid vaporization due to pyroclastic flows from Vesuvius"

Well, this should be a no brainer, given that;

"The researchers also found evidence of burst skulls, likely due to vaporizing brain matter."

(ba-dump-bump)
rrwillsj
not rated yet Oct 14, 2018
Actually, even today, most bunker systems would not long survive such an event The extra earth movements and weight would collapse and crush many of them.

Most Civil Defense and privately dug bunkers would have their oxygen supply sucked out very quickly. As happened to the people of Dresden in their air-raid shelters during the firebombing.

Deep bunkers, designed to coddle "important" command and control personnel might ride out a pyroclastic flow? Most likely loosing the upper-level support of maintenance equipment and personnel.

I suspect that before the remaining supplies are consumed? Even at the lowest level, people will succumb to the creeping heat radiating through the rock around them.

The good news is? Your tax dollars at work! Paying for sites for future giant cockroach archeologists to dig up.

Where they will find a wealth of artifacts. To be exhibited in their museums for giant cockroach students to ooh and ahh at.
carbon_unit
not rated yet Oct 14, 2018
That body fluid vaporization was preceded by the body fluid excretion.
Could have been a simultaneous phase; the hot version of throwing a cup of water in the air and having it freeze before it hits the ground.

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