Volcanoes are characterized by high and frequently episodic sediment production rates and complex patterns of primary and secondary dispersal, involving long-distance sediment transport over short time frames. The almost-universal presence of water (glacier, rivers, lakes, oceans) near volcanoes ensures that large volumes of pyroclasts are eventually transported by or in water, and end up deposited in lakes or oceans. Introduction of large volumes of pyroclasts into water result either directly from primary explosive eruptions in the form of pyroclastic flows and tephra fall that enter a water body, or from resedimentation events such as lahars, volcanogenic floods or subaqueous sediment density currents. Subaqueous explosive eruptions can introduce large volumes of pyroclastic material directly into the marine or lacustrine realm. Products of volcanic activity may overwhelm the sediment supply of an adjacent basin, or remain minor within a chiefly non-volcanic basin. Facies and persistence of deposits reflect eruption styles, transport mechanisms and environmental responses to volcanism. In subaqueous volcanic settings, resedimentation events are common, occur on the smallest slope gradients and can be triggered by earthquakes, water column disturbances of various sorts, or seafloor processes. We seek contributions on facies characterization of volcaniclastic accumulations in terrestrial, lacustrine and marine settings through study of stratigraphic successions, submarine sampling, geophysical exploration, and micro-textural analysis. The scope of this session encompasses the reconstruction of source environment, eruption style, experiments, transport and depositional processes. Case studies on hazards and risk mitigation are also welcome.