When Mount Vesuvius began to erupt in A.D. 79, most inhabitants of Pompei fled the city. But some stayed behind, and new geological evidence shows that many survived the first harrowing pumice storms by hiding in houses--only to perish hours later when more powerful waves of ash and pumice rushed inside.
Pompei was completely buried by volcanic ash, and it lay forgotten for a millennium and a half. Since the 1700s, painstaking excavations have uncovered houses replete with frescos, tiles, and artifacts of daily life. Archaeologists have even made casts of most victims, from cavities their bodies left in the ash and pumice. Now geological evidence from new and old excavations is helping to tell the fate of some of those people.
The clues came from layered volcanic deposits in an overlooked alley. Such deposits are very rare because past excavators usually cleared them to get to artifacts. Researchers from the Universitá Federico II in Napoli and the Soprintendenza Archeologica di Pompei studied the deposit and others outside the city walls to get a picture of the entire eruption. By comparing this sequence to detailed excavation records of two houses on either side of the alley, the team concluded that several bodies in the bottom floors of the two houses rested atop pumice characteristic of the first stages of the eruption. The victims probably took shelter after that so-called fallout phase, then suffocated when ash and pumice flows entered the buildings as their upper-story roofs collapsed.
Extrapolating this finding across the city, the researchers reckon that 38% of the residents perished in the first wave of fallout, mostly from collapsing buildings. All those who survived that terror probably suffocated from later currents of flowing ash, half of them inside houses and half outside, the team reports in two papers published in the 20 August Journal of Volcanology and Geothermal Research.
The two papers give a "much more detailed" cataloging of victims than ever available for Pompei, allowing "a painfully detailed reconstruction of the various causes of death," says Cynthia Damon, a classicist at Amherst College in Massachusetts. This kind of information is important for hazard assessments in communities surrounding volcanoes, she adds.