In this Feb. 24, 2006 photo, ash covers the upper flanks of the Augustine volcano summit as white steam rises from the cone. Photo by Jennifer Adleman, courtesy of Alaska Volcano Observatory/U.S. Geological Survey.

Augustine volcano viewed from the west Jan. 12, 2006 spews a large plume of smoke and ash into the atmosphere. Photo by Game McGimsey, courtesy of U.S. Geological Survey

A plume from Augustine volcano extended for about 50 miles (75 km) toward the southeast in a Dec. 12, 2005 satellite image.

Augustine volcano was visible from Homer, Alaska, just after sunset Jan. 5, 2006. Photo by Dennis Anderson, courtesy of Alaska Volcano Observatory/U.S. Geological Survey

Augustine volcano viewed from the west Jan. 12, 2006 spews a large plume of smoke and ash into the atmosphere. Photo by Game McGimsey, courtesy of U.S. Geological Survey

A scanning electron microscope image of an ash particle erupted by Augustine reveals its abrasive qualities. The ash sample was collected during the ash fall in Homer, Alaska Jan. 13, 2006, by John Paskievitch, AVO. Image by Pavel Izbekov, courtesy of AVO/UAF/USGS