- An explosion of steam, water, mud, and other material. May result from heating of groundwater by magma, and may generate base surges. (Miller, 1989)
- A type of volcanic explosion that occurs when water comes in contact with hot rocks or ash near a volcanic vent, causing steam explosions. (Brantley, 1994)
- An explosive volcanic eruption caused when water and heated volcanic rocks interact to produce a violent expulsion of steam and pulverized rocks. Magma is not involved. (Foxworthy and Hill, 1982)
- The eruption of Taal Volcano in the Philippine Islands in 1965 typifies "Phreatic" (or steam-blast) behavior. Here, a great column of steam, dust, ash, and cinders is blasted to a height of several thousand feet. This type of violent eruption is believed to occur when a large quantity of ground or surface water comes in contact with hot rock or magma in a volcanic vent and is instantly and explosively flashed to steam. [1]