Glacier 4 : A mass of ice that shows evidence of flow over a period of years as indicated by the presence of flow lines, crevasses, and other geologic evidence
U.S. Geological Survey, U.S. Department of the Interior, Volcano Hazards Program, Glossary, Washington, DC, USA 2011. http://volcanoes.usgs.gov/vsc/glossary/alluvium.ht ml, (ND/ Volc Emr - Amer) {795}