Controls on magma storage depth across the Galápagos Archipelago.

A detailed understanding of sub-volcanic magma systems and pre-eruptive processes is essential for effective monitoring and hazard mitigation of volcanic eruptions and the Galápagos Archipelago provides a natural laboratory for studying fundamental controls on magma system dynamics. The Galápagos Islands comprise multiple ocean island volcanoes, formed where a mantle plume interacts with the base of the lithosphere, generating melt which rises through the oceanic crust. This forms a series of basaltic shield volcanoes located far away from complex regional stress fields and continental crust found at plate tectonic margins. In this study, we focus on extracting the depth of magma storage beneath 11 Galápagos volcanoes using existing literature data and a new recalibration of the Olivine + Plagioclase + Augite (clinopyroxene) + Melt (OPAM) thermobarometric model (Higgins & Stock, in review). We then compare our calculated storage depths to local parameters such as edifice height, magma flux, mantle heterogeneity etc. to understand controls on the depth and distribution of magma storage across the archipelago. By identifying controls on the depth of magma storage in this simple basaltic system, we aim to expand our fundamental understanding of pre-eruptive processes which can be applied to more complex and hazardous volcanoes elsewhere, supporting global monitoring efforts and mitigation of volcanic hazards.