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Unformatted text preview: Bottom line: Pyroclastic flows are generally
generated in one of two
ways Lava dome collapse Peleean & Merapi type
flows Generally produces “block
and ash flows” Volumes are limited Eruptive Column collapse Generally produces pumice
flows or ignimbrites Alternatively “Sourfriere” or
“St. Vincent” type flows Large range in volume,
from small to extremely
large. 6 Types of Block & Ash Flows S t. V in c e n t o r S o u r fr ie r e t y p e Collapse of small eruptive column associated with
vulcanian More vesiculated than others, but not as vesiculated
as pumice flows P e le e a n t y p e Explosive dome collapse Intermediate amounts of vesiculated material M e ra p i t y p e Gravitational dome collapse High proportion of poorly vesiculated material Soufriere Hills Dome Collapse 7 Soufriere Hills Dome Collapse Soufriere Hills Dome Collapse 8 Soufriere Hills Dome Collapse Modeling Column Collapse How do large pyroclastic flows form from column
collapse? Why do they move so fast
and so far? Model of...
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This document was uploaded on 03/04/2014 for the course EAS 458 at Cornell University (Engineering School).
- Fall '06