Petrological and monitoring insights into the mechanisms driving eruptions of Kelud volcano, Indonesia

Abstract

Our capacity to anticipate volcanic eruptions depends on accurate interpretation of unrest signals coupled with understanding of the magmatic system and processes. This is challenging for most volcanoes, including Kelud (Indonesia), that erupts effusively and explosively. In this thesis, I address some unknowns to this topic by quantitatively determining the magmatic processes, storage conditions, timescales, and ascent rates of three eruptions at Kelud (1990Kelud ( , 2007Kelud ( , 2014. I relate these variables to the time series of monitoring data for the same events. I show that explosive eruptions are likely driven by fluid accumulation and degassing that began months before eruption. I performed experiments to find that magma storage conditions for explosive and effusive eruptions were similar, and I demonstrate that ascent rates and viscosity vary with eruption style. These results can be used to improve volcanic hazard assessment and monitoring through robust petrology-based conceptual frameworks for different eruption styles.