Recurrent explosive eruptions from a high-risk Main Ethiopian Rift volcano throughout the Holocene

Corbetti caldera, the southernmost large volcanic system in Ethiopia, is categorized by the World Bank at 18 the highest level of uncertainty in terms of hazard and risk. The number and frequency of past explosive eruptions at Corbetti has hitherto been unknown, with the volcanic record based only on outcrop sequences, which do not often record complete stratigraphies. In contrast, lake sediments may yield comprehensive, stratigraphically-resolved dossiers of past volcanism. Here we use volcanic ash layers preserved in sediments from three Main Ethiopian Rift lakes to provide the first <10 ka record of volcanism for Corbetti. Corbetti has erupted explosively throughout the Holocene at an average return period of ~800 years. We show that future explosive eruptions are likely and could blanket nearby Awassa and Shashamene, home to ~260,000 people, with pumice deposits. The threat posed by Corbetti has, until now been, underestimated. Our data indicates future eruptions could have significant societal impacts. Our lake sediment tephrostratigraphic approach shows significant potential for application throughout the East African Rift system, and is essential to understanding volcanic hazards in this rapidly developing region.publishersversionPeer reviewe