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Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption

Explosive volcanic super-eruptions of several hundred cubic kilometres or more generate long run-out pyroclastic density currents the dynamics of which are poorly understood and controversial. Deposits of one such event in the southwestern USA, the 18.8 Ma Peach Spring Tuff, were formed by pyroclast...

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Autores principales: Roche, O., Buesch, D. C., Valentine, G. A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786679/
https://www.ncbi.nlm.nih.gov/pubmed/26947753
http://dx.doi.org/10.1038/ncomms10890
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author Roche, O.
Buesch, D. C.
Valentine, G. A.
author_facet Roche, O.
Buesch, D. C.
Valentine, G. A.
author_sort Roche, O.
collection PubMed
description Explosive volcanic super-eruptions of several hundred cubic kilometres or more generate long run-out pyroclastic density currents the dynamics of which are poorly understood and controversial. Deposits of one such event in the southwestern USA, the 18.8 Ma Peach Spring Tuff, were formed by pyroclastic flows that travelled >170 km from the eruptive centre and entrained blocks up to ∼70–90 cm diameter from the substrates along the flow paths. Here we combine these data with new experimental results to show that the flow's base had high-particle concentration and relatively modest speeds of ∼5–20 m s(−1), fed by an eruption discharging magma at rates up to ∼10(7)–10(8) m(3) s(−1) for a minimum of 2.5–10 h. We conclude that sustained high-eruption discharge and long-lived high-pore pressure in dense granular dispersion can be more important than large initial velocity and turbulent transport with dilute suspension in promoting long pyroclastic flow distance.
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spelling pubmed-47866792016-03-16 Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption Roche, O. Buesch, D. C. Valentine, G. A. Nat Commun Article Explosive volcanic super-eruptions of several hundred cubic kilometres or more generate long run-out pyroclastic density currents the dynamics of which are poorly understood and controversial. Deposits of one such event in the southwestern USA, the 18.8 Ma Peach Spring Tuff, were formed by pyroclastic flows that travelled >170 km from the eruptive centre and entrained blocks up to ∼70–90 cm diameter from the substrates along the flow paths. Here we combine these data with new experimental results to show that the flow's base had high-particle concentration and relatively modest speeds of ∼5–20 m s(−1), fed by an eruption discharging magma at rates up to ∼10(7)–10(8) m(3) s(−1) for a minimum of 2.5–10 h. We conclude that sustained high-eruption discharge and long-lived high-pore pressure in dense granular dispersion can be more important than large initial velocity and turbulent transport with dilute suspension in promoting long pyroclastic flow distance. Nature Publishing Group 2016-03-07 /pmc/articles/PMC4786679/ /pubmed/26947753 http://dx.doi.org/10.1038/ncomms10890 Text en Copyright © 2016, Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Roche, O.
Buesch, D. C.
Valentine, G. A.
Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption
title Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption
title_full Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption
title_fullStr Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption
title_full_unstemmed Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption
title_short Slow-moving and far-travelled dense pyroclastic flows during the Peach Spring super-eruption
title_sort slow-moving and far-travelled dense pyroclastic flows during the peach spring super-eruption
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786679/
https://www.ncbi.nlm.nih.gov/pubmed/26947753
http://dx.doi.org/10.1038/ncomms10890
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