Eruption of the Nevado del Ruiz Volcano, Colombia, On 13 November 1985: Tephra Fall and Lahars

Science  29 Aug 1986:
Vol. 233, Issue 4767, pp. 961-963
DOI: 10.1126/science.233.4767.961


A small Plinian eruption of the Nevado del Ruiz volcano in Colombia ejected 3.5 x 1010 kilograms of mixed dacite and andesite tephra on 13 November 1985, with a maximum column height of 31 kilometers above sea level. Small pyroclastic flows and surges, generated during the initial stage of the eruption, caused surface melting of approximately 10% of the volcano's ice cap, leading to meltwater floods. The erosive floods incorporated soils and loose sediments from the volcano's flanks and developed into lahars, which claimed at least 25,000 lives.