Global Volcanism Program | Image GVP-04341
Two weeks after the 13 November 1985 eruption, a plume rises from Las Arenas, the summit crater of Nevado del Ruiz. This view from the NNW shows pyroclastic surge and pyroclastic flow deposits mantling the summit icecap. Grooves descending the upper glacier surface were scoured by pyroclastic surges, which reached 5.5 km NW and NE of the summit. Melting of the summit icecap during the eruption led to devastating lahars that traveled as far as 100 km from the volcano and caused 24,000 fatalities.
Photo by Norm Banks, 1985 (U.S. Geological Survey).
This image is made available as a Public Domain Work, but proper attribution is appreciated.