Unravelling the gap between the probabilistic volcanic hazard and risk perception: A comparative study of tephra fallout at Etna and Vesuvius volcanoes

Volcanic risk management frequently encounters a significant gap between Probabilistic Volcanic Hazard Assessment and subjective risk perception. This study addresses this issue by comparing communities exposed to tephra fallout from two contrasting volcanoes in Southern Italy: the persistently active Etna and the quiescent Vesuvius. A survey of residents in proximal (high exposure: Catania, Nola) and distal (lower exposure: Siracusa, Pisticci) zones assessed hazard knowledge, multidimensional risk perception, institutional trust, and preparedness. The results identify distinct socio-cognitive paradigms. In the Etna proximal zone, chronic exposure results in hazard normalization. Residents perceive a high probability of tephra fallout but dissociate this from personal threat, relying on individual coping strategies and disengaging from institutional preparedness. In the Vesuvius proximal and Etna distal zones, a preparedness paradox emerges: High theoretical awareness and willingness to adopt protective actions coexist with low practical readiness due to insufficient hazard-specific training. Geographical distance further differentiates perception. The Etna distal area maintains realistic awareness due to frequent volcanic activity, whereas the Vesuvius distal area (Pisticci) exhibits a distal shadow effect, where distance significantly reduces risk salience despite objective transboundary threats. Although trust in scientists and the Civil Protection Agency remains consistently high, sources of hazard knowledge vary considerably across communities. These results suggest that Disaster Risk Reduction strategies should move beyond uniform approaches. Risk communication should be context-specific, aiming to disrupt habituation in chronically exposed communities and to transform abstract concern into actionable preparedness in quiescent and distal regions