Role of lava tubes in flows from the Observatory Vent, 1971 Eruption on Mount Etna

Abstract
The role of tubes in aa flows may be more important than previously recognized. On Etna they are commonly found in the near-vent areas of aa flows. A study of tubes associated with the 1971 Observatory Vent on Etna suggests that ephemeral boccas on the flow surface downslope of the main vent were fed by tubes.