What is a cinder volcano?
A cinder cone or scoria cone is a steep conical hill of tephra (volcanic debris) that accumulates around and downwind from a volcanic vent. The rock fragments, often called cinders or scoria are glassy and contain numerous gas bubbles "frozen" into place as magma exploded into the air and then cooled quickly.Cinder cones range in size from tens to hundreds of meters tall and are made of pyroclastic material. Many cinder cones have a bowl-shaped crater at the summit.