One of history's great disaster mysteries may be solved—the case of the largest volcanic eruption in the last 3,700 years. Nearly 800 years ago, the blast that was recorded, and then forgotten, may also have created a "Pompeii of the Far East," researchers suggest, which might lie buried and waiting for discovery on an Indonesian island.

The source of an eruption that scattered ash from pole to pole has been pinpointed as Samalas volcano on Indonesia's Lombok Island. The research team, led by geographer Franck Lavigne of the Université Paris 1 Panthéon-Sorbonne, has now dated the event to between May and October of 1257. The findings were published today in the Proceedings of the National Academy of Sciences....