The eruption of Mount Vesuvius around 2000 years ago caused one man鈥檚 brain to explode and turned the fragments to glass. The discovery is the only known instance of soft tissue turning to glass and sheds new light on how eruptions kill 鈥� and how we might protect people.
The volcanic disaster struck in AD 79, burying the cities of Pompeii, Herculaneum and Stabiae in thick layers of ash that eventually solidified. At least 1500 bodies and thousands of ancient papyrus scrolls have been found preserved in this material.
One of the remains belonged to a man lying in his bed, who had glass-like fragments inside his skull. When it the material was thought to be an extremely rare organic glass formed from brain tissue. Now, at Roma Tre University in Italy and his colleagues have confirmed this and worked out in detail how it happened.
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Due to intense heat, the brain would have exploded as water in it rapidly evaporated, the researchers concluded. The fragments remaining in the skull turned to glass as a result of rapid cooling.
鈥淲e didn鈥檛 find a brain. We found bits and pieces,鈥� says Giordano. 鈥淎 few times [during the research] I really got into the human side: you鈥檙e thinking about this person, and I was really affected by that.鈥�
Although the brain suffered catastrophic damage, portions of it are extremely well preserved. Complex networks of neurons and axons can still be seen, and the researchers detected proteins common in human brain tissue.
X-ray and electron microscopy analysis revealed that the brain must have been heated above 510掳C before cooling rapidly, in order to form a true glass with no crystalline structure. Because the pyroclastic flow of ash and detritus that buried the city is known to have only reached 465掳C, this means that there must have first been a super-hot cloud of ash and gas that engulfed the area, killed residents, then quickly dissipated.
鈥淚t鈥檚 not the heating process that transforms things into glass,鈥� says Giordano. 鈥淭he heating process would bake it, would transform it into charcoal, would vaporise it. But it鈥檚 not going to make it glass. In order to make a glass, you need a fast cooling.鈥�
Giordano says the discovery paints a terrifying picture of how volcanoes kill, but also suggests new ways to protect people.
If evacuation isn鈥檛 possible, and people are outside the physically destructive flow of ash and rock that flattens structures, there is still intense heat of the kind that killed the man from Herculaneum. But shelters that insulate the people in them could allow some to survive.
鈥淚n the case of being engulfed within an ash cloud, what kills you is the heat 鈥� but there is also the potential to survive if you are sheltered from the heat,鈥� says Giordano.
Scientific Reports
Historic Herculaneum - Uncovering Vesuvius, Pompeii and ancient Naples: Italy
Embark on a captivating journey where history and archaeology come alive through the ruins of Pompeii, Herculaneum, and Mount Vesuvius. Based in Naples, you will be accompanied by volcanologist Professor Christopher Kilburn as well as local expert guides who will offer insight into the history and ongoing excavations of this remarkable region.
