|Credit: Pixabay/CC0 Public Domain|
A team of geologists hailing from the University of Roma Tre has unraveled the long-standing mystery of why the bodies of people residing in Herculaneum, a town near Pompeii, were not adequately preserved following the catastrophic eruption of Mount Vesuvius. In their recently published paper in the esteemed journal Scientific Reports, the research group divulges their findings that point to a pyroclastic current hitting Herculaneum shortly after the volcanic eruption, resulting in the rapid vaporization of the unfortunate inhabitants.
Previous research had posited the occurrence of pyroclastic currents, wherein scorching hot gases and particles surge down the slopes of the volcano and impact areas in close proximity. These currents are known to reach staggering temperatures, often surpassing 550°C, as evidenced by studies of the 1902 eruption in Martinique.
In this latest study, the geologists meticulously gathered samples of carbonized wood from various locations within Herculaneum and conducted thorough laboratory analyses. Their investigations revealed compelling evidence that the wood samples had been exposed to an exceedingly high-temperature gas for a brief duration, indicative of a diluted pyroclastic density current (PDC). This finding corroborated the occurrence of a pyroclastic flow hitting Herculaneum during the catastrophic eruption of Mount Vesuvius in 79 AD, which resulted in the incineration of the town's inhabitants.
In contrast, the people of Pompeii were spared the same fate as they were situated farther away from the volcano. Instead, they were tragically buried alive in a thick layer of ash that blanketed the city during the volcanic eruption. The recent research sheds new light on the differential preservation of human remains in Herculaneum and Pompeii, providing a deeper understanding of the catastrophic events that unfolded during the eruption of Mount Vesuvius nearly two thousand years ago.
Further investigation conducted by the research team revealed that the gas temperatures during the pyroclastic density current (PDC) that struck Herculaneum had exceeded a scorching 550°C. Additionally, evidence of several subsequent PDCs traversing the town was found, though these were comparatively cooler. Over time, Herculaneum, much like Pompeii, was eventually buried under layers of volcanic debris.
The researchers posit that such a powerful blast of searing gas and particles would have reduced human victims to mere piles of charred bones and ash, elucidating the absence of well-preserved bodies in Herculaneum, in contrast to the preserved remains found in Pompeii. However, the team did make a unique discovery: partial remains of an organ, specifically a skull with a vitrified brain inside, at the Collegium Augustalium. This finding suggested that the brain had been incinerated at an exceptionally high temperature and then rapidly cooled, transforming it into a glass-like substance.
The research team emphasizes that their findings should serve as a cautionary reminder for modern inhabitants of Naples, a city in close proximity to Mount Vesuvius. The possibility of a PDC occurrence in the event of another volcanic eruption should not be underestimated, highlighting the importance of preparedness and vigilance in regions prone to such natural disasters.
Source: Alessandra Pensa et al, A new hazard scenario at Vesuvius: deadly thermal impact of detached ash cloud surges in 79CE at Herculaneum, Scientific Reports (2023). DOI: 10.1038/s41598-023-32623-3