Global Volcanism Program | Image GVP-10025
Pyroclastic surges completely devastated vegetation on the flanks of El Chichón volcano to distances up to 8 km from the crater. Still-steaming pyroclastic-flow and -surge deposits are seen in this early April photo at Francisco León, 5 km SSW of the crater. Three major pyroclastic flows swept the flanks of the volcano on April 3 and 4, devasting an area of 154 sq km; all three surges reached Francisco León. Pyroclastic surges swept over ridges as high as 300 m and left sharp trimlines at their margins.
Photo by Servando De la Cruz-Reyna, 1982 (Universidad Nacional Autónoma de México).