Global Volcanism Program | Image GVP-07822
A large pyroclastic flow sweeps down the flank of Santiaguito lava dome on July 19, 1989. The pyroclastic flow and ash column are seen here from just west of El Palmar (10 km south of the dome) about 5 minutes after the start of the explosion. The summit of Santa María volcano is visible immediately to the right of the ash column, which rose to 4 km above the vent. The pyroclastic flow traveled 5 km down the Río Nimá and was perhaps the largest since the major 1929-34 activity.
Photo by Mike Conway, 1989 (Michigan Technological University).