Global Volcanism Program | Image GVP-10032
The terminus of a pyroclastic-flow lobe about 4 km NE of the crater, south of Nicapa, is seen within a day or two of its emplacement on April 4, 1982. The Nicapa valley was the site of the most extensive pyroclastic flows of the 1982 eruption. Up to three units, each 2-15 m thick and containing abundant pumice blocks 15-40 cm in diameter, are present. Light-colored ash from the April 4 pyroclastic surges covers a broad radial area around the crater to distances 1.5 km beyond the extent of the pyroclastic flows in the Nicapa valley.
Photo by Servando De la Cruz-Reyna, 1982 (Universidad Nacional Autónoma de México).