Craters of habit: Patterns of deformation in the western Galápagos

Abstract

The western Galápagos islands of Fernandina and Isabela comprise six active volcanoes that have deformed since first observed by satellite radar in the early 1990s. We analyse new (2015–2022) displacement time series at Alcedo, Cerro Azul, Darwin, Fernandina, Sierra Negra, and Wolf volcanoes in the context of deformation and unrest since 1992. Previous discussions of volcano deformation have focused on eruptions, major intrusive episodes, and the structure of sub-volcanic systems. We discuss the full geodetic record of deformation and show that the style of eruptions, characteristics of unrest and deformation are distinctive at each volcano. These characteristic differences in deformation and unrest styles between the volcanoes have persisted for at least three decades, since the first satellite radar measurements. These consistent differences in shallow magma storage and eruptive dynamics reflect the influence of “top-down” factors and evolutionary stage, providing a basis to understand volcanic unrest here, and to inform monitoring strategies.