"Violent strombolian" eruptions (VS), characterized by voluminous ash production and extensive basaltic lava flows, are a common form of volcanic activity in subduction zone environments. However, this activity has received scant recent attention from the volcanological community, in part because these eruptions do not fit neatly into existing classification schemes. To provide a more comprehensive physical understanding of VS eruptions, Profs. Cashman and Wallace (University of Oregon) will collaborate with Prof. Rosi (University of Pisa) and Prof. Delgado (UNAM, Mexico) to conduct a comparative and multi-disciplinary investigation of deposits produced by well-described violent strombolian eruptions of Paricutin (1943, Mexico) and Vesuvius (1906, Italy). Important issues to be addressed include the role of magmatic volatiles in generating violent strombolian eruptions, mechanisms of ash generation, rapid transitions in eruption styles, and the characteristic relationship between explosive and effusive (lava flow) activity.
The broader impacts of this study relate to hazard assessment, as the high ash content and large dispersal range generated by violent strombolian explosions may cause severe economic disruption through problems of ash disposal and extensive disruption of air traffic, as illustrated by recent violent strombolian activity at Mt. Etna, Italy. Because of the potential for this type of activity in many parts of the world, the PIs have designed the educational component of the proposed work to include American, Mexican and Italian students, who will be involved with hazard assessment in addition to basic research.
