Ash Flow 2 : A pyroclastic flow consisting predominantly of ash-sized (less than 4 millimeters in diameter) particles. Also called a glowing avalanche if it is of very high temperature. (Foxworthy and Hill, 1982)
U.S. Department of the Interior, U.S. Geological Survey, US Geological Society (USGS), Glossary of Volcano and Related Terminology, USGS/Cascades Volcano Observatory, Vancouver, Washington, USA 2006. http://vulcan.wr.usgs.gov/Glossary/volcano_termino logy.html, (ND/ Volc Sci - Amer) {493}