Eruption of the nevado del ruiz volcano, Colombia, on 13 november 1985: tephra fall and lahars

Science. 1986 Aug 29;233(4767):961-3. doi: 10.1126/science.233.4767.961.

Abstract

A small Plinian eruption of the Nevado del Ruiz volcano in Colombia ejected 3.5 x 10(10) 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.