The eruption of Mount Vesuvius in 79 AD instantaneously destroyed the Roman cities of Pompeii and Herculaneum, yet the remains of their victims present two vastly different archaeological pictures. While Pompeii is famous for the plaster casts that preserve the final moments of its dead in voids left within the ash, Herculaneum offers a unique collection of skeletal remains. This difference in preservation is a direct result of the specific volcanic mechanism that overwhelmed each city. The forensic analysis of the Herculaneum skeletons has provided significant details about the eruption’s lethal power and the health of the Roman population.
The Eruption’s Mechanism of Destruction
Herculaneum’s proximity to Mount Vesuvius meant it experienced a far more devastating form of volcanic assault than Pompeii. The first phase of the eruption involved an ash and pumice fall that mainly drifted southeast toward Pompeii. Herculaneum was largely spared during this initial stage, which allowed many residents to evacuate, but those who remained were caught by the first of several pyroclastic surges.
A pyroclastic surge is a superheated cloud of gas and fine ash that travels down the volcano’s slopes at extreme speeds. The surge that enveloped Herculaneum was estimated to be between 400°C and 500°C (750°F to 930°F) and moved at nearly 180 miles per hour. This extreme heat caused instantaneous death by thermal shock, vaporizing the victims’ soft tissues and leaving behind complete skeletons.
In contrast, the victims at Pompeii, located farther away, were primarily killed by the later pyroclastic surges at lower temperatures, or by falling ash and collapsing roofs. The lower heat at Pompeii, estimated to be around 300°C (572°F), allowed the bodies to be covered in ash before they fully decomposed. The subsequent decay of the soft tissue created the famous voids that archaeologists later filled with plaster to form casts. The unique level of heat that hit Herculaneum explains why no such voids exist there.
Discovery in the Boat Houses
For centuries, archaeologists thought Herculaneum’s residents had successfully evacuated, as few human remains were found within the city’s main structures. This belief was overturned in the 1980s when excavations reached the ancient shoreline and uncovered a series of twelve waterfront chambers, or boat houses (fornici). These arched vaults were once right on the beach, providing what people believed was safe shelter from the eruption.
Inside these boat houses, researchers discovered the remains of approximately 300 individuals huddled together. These were people who had sought refuge by the sea. The initial pyroclastic surge instantly killed them, and the subsequent layers of ash and consolidated volcanic material, or tuff, buried the area to a depth of up to 20 meters.
The remains found in this location were articulated skeletal remains, preserved within the hardened volcanic matrix. The discovery provided a complete cross-section of the Roman population, including men, women, and children. This sudden find fundamentally changed the understanding of the site, confirming that a large segment of the population had perished at the same instant.
Unique Scientific Findings from the Skeletal Remains
The exceptional preservation of the Herculaneum skeletons allowed forensic scientists to uncover details about the moment of death. Analysis of the skulls revealed signs of thermal fracturing, with many displaying a starburst pattern of cracks and some parts having exploded outward. This phenomenon is hypothesized to be caused by the rapid vaporization of brain matter and bodily fluids due to the intense heat. As the fluids boiled, the resulting steam pressure built up until it fractured the bone.
Investigators also found red and black residues encrusting the bones and surrounding volcanic ash, even within the intracranial cavities. Using techniques like mass spectrometry, scientists identified these residues as containing high concentrations of iron and iron oxides. The presence of heme iron components, found in blood, suggests that soft tissues and blood were instantly vaporized, and the iron was thermally decomposed and deposited onto the bones.
Beyond the cause of death, analysis of the bone and teeth offered a window into the population’s general health and diet. Researchers noted a low incidence of dental decay, possibly due to a diet low in sugar and high in fluoride from seafood. However, the skeletons also showed high frequencies of conditions like osteoarthritis and pleurisy, a respiratory inflammation, which may have been caused by the polluted air from indoor cooking fires. The skeletons provided a wealth of paleobiological data, revealing the everyday lives and ailments of an ancient Roman community.