Global Volcanism Program | Image GVP-01828
A crowd of spectators watches a pyroclastic flow sweeping down the SE flank of Mayon volcano on 24 September 1984. They stand on the surface of a deposit from a large lahar emplaced during an eruption in 1814. The pyroclastic flow seen here traveled about 6 km. Strong explosions the previous day created notches in the SE and east crater rims that funneled pyroclastic flows down ravines in those directions.
Photo by Norm Banks, 1984 (U.S. Geological Survey).