Eruption-triggered avalanche, flood, and lahar at Mount St. Helens - Effects of winter snowpack

R. B. Waitt; T.C. Pierson; N. S. MacLeod; R. J. Janda; B. Voight; R. T. Holcomb

doi:10.1126/science.221.4618.1394

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Eruption-triggered avalanche, flood, and lahar at Mount St. Helens - Effects of winter snowpack

R. B. Waitt·T.C. Pierson·N. S. MacLeod·R. J. Janda·B. Voight·R. T. Holcomb

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Abstract

An explosive eruption of Mount St. Helens on 19 March 1982 had substantial impact beyond the vent because hot eruption products interacted with a thick snowpack. A blast of hot pumice, dome rocks, and gas dislodged crater-wall snow that avalanched through the crater and down the north flank. Snow in the crater swiftly melted to form a transient lake, from which a destructive flood and lahar swept down the north flank and the North Fork Toutle River.

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Source-reported bounding extent: 46.1110590427451° to 46.2547357549887° latitude; -122.31513893613513° to -122.02858378694158° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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R. B. Waitt, T.C. Pierson, N. S. MacLeod, R. J. Janda, B. Voight, R. T. Holcomb. 1983. Eruption-triggered avalanche, flood, and lahar at Mount St. Helens - Effects of winter snowpack. https://doi.org/10.1126/science.221.4618.1394

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