Steam billows from newly exposed, hot pyroclastic debris in the canyon draining the summit crater of Redoubt Volcano. More than 30 meters (100 ft) of coarse sand to boulder sized material accumulated in this canyon during the 1989 to 1990 eruptions of the volcano. Subsequent downcutting by meltwater occasionally caused steam explosions as water came into contact with hot pyroclastic material. Photograph by C. Gardner, U.S. Geological Survey, July 16, 1990.
Image courtesy of AVO / U.S. Geological Survey.