Transitions: comparing timescales of eruption and evacuation at Volcán de Fuego (Guatemala) to understand relationships between hazard evolution and responsive action

During volcanic crisis, effective risk mitigation requires that institutions and local people respond promptly to protect lives and livelihoods. In this paper, we ask: over what timescales do explosive paroxysmal eruptions evolve? And how do these timescales relate to those of people’s past responses? We explore these questions by comparing timescales of eruptions and evacuations for several recent events at Volcán de Fuego (Guatemala) to identify lags in evacuation and determine the drivers of these lags. We use multiple geophysical datasets for explosive paroxysmal eruptions (“paroxysms”) in 2012–2018 to constrain timescales of eruptive evolution. In parallel, we determine timescales of response and the impacts of uncertainty and eruptive behaviours on decision-making through interviews with institutional and local actors. We then compare eruption and response timescales to explore the drivers for decision-making, whether volcanic, institutional, or personal. We find that eruption and response timescales are comparable. However, we also find that periods of decision-making and warning dissemination delay response until well after eruptive onset. We document how in recent eruptions, response occurs during eruptive climax when risk is at peak. We use paired timelines to elucidate the key drivers of this ‘response lag’ and show that despite the high levels of forecasting uncertainty, response times could be improved by agreed means to collaborate through shared information and agreed actions. We conclude by considering how the analysis presented here might be useful to different actors who share the goal of preserving lives and livelihoods at Fuego, focussing on how community’s needs can be met such that during an eruptive crisis the community can evacuate in time. Our analysis offers practical insights for people working to mitigate risk to populations near active volcanoes around the world.