Herculaneum and Pompeii were both affected by Vesuvius's eruption in 79 CE. Different burial conditions preserved some wood and other organic materials at Herculaneum.
Carbonized papyrus scrolls from a villa became subjects of research. New technologies allow scholars to attempt reading fragile scrolls without fully unrolling them.
Eruption of 79 AD
The course and timeline of the eruption can be reconstructed based on archaeological excavations and two letters from Pliny the Younger to the Roman historian Tacitus.
At around 1 pm on the first day of eruption, Mount Vesuvius began spewing volcanic material thousands of metres into the sky. After the plume had reached a height of 27–33 km (17–21 mi), the top of the column flattened, prompting Pliny to describe it to Tacitus as a stone pine tree. The prevailing winds at the time blew toward the southeast, causing the volcanic material to fall primarily on the city of Pompeii and the surrounding area. Since Herculaneum lay west of Vesuvius, it was only mildly affected by the first phase of the eruption. While roofs in Pompeii collapsed under the weight of falling debris, only a few centimetres of ash fell on Herculaneum, causing little damage; nevertheless, the ash prompted most inhabitants to flee.
The volcano continued spewing up a high-altitude column from which ash and pumice began to fall, blanketing the area. At 1 am the next day, the eruptive column collapsed onto Vesuvius and its flanks. The first pyroclastic surge, formed by a mixture of ash and hot gases, flowed down the mountain and through the mostly-evacuated town of Herculaneum at 160 km/h (100 mph). A succession of six flows and surges buried the city's buildings to approximately 20 m (66 ft) depth, causing little damage in some areas and preserving structures, objects and victims almost intact.
However, other areas were damaged significantly, knocking down walls, tearing away columns and other large objects; a marble statue of Marcus Nonius Balbus near the baths was blown 15 m (49 ft) away and a carbonised skeleton was found lifted 2.5 m (8 ft 2 in) above ground level in the garden of the House of the Relief of Telephus.
Villa of the Papyri
The famous Villa of the Papyri, was built on the seashore on four terraces. It is thought to have belonged to consul Lucius Calpurnius Piso Caesoninus, Julius Caesar's father-in-law, who was a patron of poets and philosophers and built there the only ancient library that has survived virtually intact.
Between 1752 and 1754, a number of blackened, unreadable papyrus scrolls were recovered from the Villa of the Papyri by workmen. These scrolls became known as the Herculaneum papyri or scrolls, the majority of which are today stored at the National Library, Naples. Although badly carbonized, a number of scrolls have been unrolled with varying degrees of success. Computer-enhanced multi-spectral infrared imaging helped make the ink legible. Researchers increasingly investigated whether X-rays could reveal writing inside unopened rolls. The same techniques could be applied to the rolls waiting to be discovered in the as-yet unexcavated part of the villa, eliminating the risk of potential damage from unrolling. Later CT scan revealed the scrolls' fibres structure, sand, and other debris trapped in the scrolls. Those early structural findings improved understanding of the scrolls, but the scans had not yet made their ink readable.
Two of the rolls stored at the French National Academy in Paris have been extensively examined by X-ray in summer 2009. However, the text imaging failed because Roman writers likely used carbon-based inks, essentially invisible to the X-ray scans. Further attempts faced the same difficulty in distinguishing ink from carbonized papyrus.
In 2015, a team of scientists managed to increase the contrast between the carbon ink and the carbon-based papyrus using X-ray Phase Contrast Tomography, and read Greek words along the outer papyrus, marking "a revolution for papyrologists". The 2015 study recovered isolated words rather than a continuous readable text; more complete virtual reading remained a research goal at that stage.
In 2024 the winners of a contest called the Vesuvius Challenge, with the help of AI, managed to reveal hundreds of words across 15 columns of text, corresponding to around 5% of a scroll.