Volcanic ash

Fine pyroclastic material (under 2.0 mm diameter; under 0.063 mm diameter for fine ash). The term usually refers to the unconsolidated material but is sometimes also used for its consolidated counterpart, tuff. _{(Neuendorf, K.K.E. and others, 2011)}

• DGGS online catalog of government agency publications relating to: Volcanic ash
• Alaska Volcano Observatory (AVO): Homepage
• U.S. Geological Survey (USGS): Volcanic ash...what it can do and how to prevent damage