Explosive, ash-producing volcanic eruptions are a significant natural
hazard with the potential for loss of life, economy, and infrastructure.
Turrialba is an active stratovolcano located in the Central Cordillera
of Costa Rica. The edifice is located only 35 km east-northeast of Costa
Rica's capital city and poses a threat to its central valley, the social
and economic hub where more than half of the population resides. The
most recent eruption took place in 2016-2017, consisting of four
eruption phases. Preliminary observations using SEM show significant
morphological differences between the various eruption phases, including
the amount of dust and crystals that are present. The morphology of
volcanic ash is fundamental to our understanding of magma fragmentation,
and in transport modeling of volcanic plumes and clouds. The chemistry
of the ash particles produced by fragmenting magmatic foams may affect
their evolving morphology throughout the various stages of eruption. In
addition, eruption energetics may play a role in ash morphology.
Separating the roles of chemical heterogeneity and evolving energetics
requires careful examination of ash morphology and its relation to
composition. In this way, we take some initial steps in closing the
knowledge gap between eruption mechanisms and how and why these
mechanisms are exhibited in the morphology of ash during explosive
eruptions.