A series of basaltic tuff rings and a scoria cone occupy the western tip of Ambrym, at the subaerial end of a fissure system that cuts across the length of the island. The largest tuff ring is about 1 km in diameter. The tuff rings were produced by phreatic eruptions when magma interacted with the water table or near-surface, water-saturated sediments along the coast. At higher elevations along the rift zone, scoria cones predominate.

Photo by Hunting Surveys, London (published in Green and Short, 1971).

This image is made available under the Creative Commons BY-NC-ND 4.0 license terms.

Keywords: crater | tuff ring | scoria cone

Ambrym