Global Volcanism Program | Image GVP-01310
A large Plinian ash plume from Pinatubo towers above Clark Air Base on 12 June 1991. The eruption column reached an altitude of 19 km. This was the first in a series of powerful eruptions that reached a climax on 15 June. The eruption that day produced a series of large pyroclastic flows that covered all sides of the volcano and resulted in collapse of the summit, creating a 2.5-km-wide caldera.
Photo by Dave Harlow, 1991 (U.S. Geological Survey).