| Abstract: | A generally unrecognized type of pyroclastic deposit was produced by rapid avalanches of intimately mixed snow and hot pyroclastic debris during eruptions at Mount St. Helens, Nevado del Ruiz, and Redoubt Volcano between 1982 and 1989. These "mixed avalanches‘ traveled as far as 14 km at velocities up to ~27 m/s, involved as much as 107 m3 of rock and ice, and left unmelted deposits of single flow units as thick as 5 m. During flow downslope, heat transfer from hot rocks to snow produced meltwater that partially saturated the mixtures, apparently giving these mixed avalanches mobilities equal to or greater than those of "dry‘ debris avalanches of similar volume. After melting and desiccation, the deposits are highly susceptible to erosion and unlikely to be well preserved in the stratigraphic record. -Authors |
| Genre: | Article |
| ProdID: | 70017202 |
| Citation Author: | Pierson, T. C.; Janda, R. J. |
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| Citation End Page: | 1358 |
| Citation Issue: | 10 |
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| Citation Language: | English |
| Citation Larger Work Title: | Geological Society of America Bulletin |
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| Citation Number Of Pages: | 8 |
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| Citation Search Results Text: | Volcanic mixed avalanches: a distinct eruption-triggered mass-flow process at snow-clad volcanoes; 1994; Article; Journal; Geological Society of America Bulletin; Pierson, T. C.; Janda, R. J. |
| Citation Start Page: | 1351 |
| Citation Volume: | 106 |
| Citation Year: | 1994 |
| Type: | citation/reference |
| Text: | Volcanic mixed avalanches: a distinct eruption-triggered mass-flow process at snow-clad volcanoes; 1994; Article; Journal; Geological Society of America Bulletin; Pierson, T. C.; Janda, R. J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Jan 1994 00:00 -0600 |
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