Archaeoseismological evidence of a disruptive Late Antique earthquake at Alba Fucens (central Italy)

Paleoseimological investigations in the 1990s identified a surface faulting event in the Fucino Plain (central Italy) related to the 5th-6th century AD. This event originated along the same seismogenic source responsible for the 1915 earthquake (Mw 7.0) that caused damage over a vast region, including Rome. This earthquake was associated to the one that was responsible for damage to the Colosseum in Rome, just before 484 AD or 508 AD. Considering that this event was energetic enough to create surface faulting, significant effects would be expected on the settlements of the 5th-6th century AD. In modern archaeological publications, the destruction of Alba Fucens in the north-western sector of the Fucino area has been related to the effects of a destructive earthquake that occurred during the Late Antiquity. Archaeological evidence on the effects of the earthquake is mostly made up of collapsed layers including columns, statues, coins and other materials and layers formed by burnt remains (mainly parts of the wooden structures of the buildings). However, this Late Antique earthquake has been attributed to the 4th century AD in archaeological literature. With this discrepancy in mind, we have carried out a study of the archaeological sources and have collected new archaeological data, in order to cast light on this chronological problem. The review of the published and unpublished archaeological information regarding the excavations carried out at Alba Fucens between 1949 and 1979, plus the data collected at new excavations that have been going on since 2004 at different sites in the Fucino basin, suggest that the destruction of Alba Fucens and other towns and settlements of the region occurred later than assumed in archaeological literature. On the whole, the gathered data are consistent with the published paleoseismological information, and suggest that this destruction occurred during the 5th-6th century AD. Although the processing of the data concerning the archaeological investigations at Alba Fucens in 2006-2008 is still ongoing, the current, most plausible hypothesis at present, is that the 484-508 AD earthquake was probably responsible for the destruction of Alba Fucens.