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Estimating rates of decompression from textures of erupted ash particles produced by 1999-2006 eruptions of Tungurahua volcano, Ecuador

2012; Geological Society of America; Volume: 40; Issue: 7 Linguagem: Inglês

10.1130/g32948.1

1943-2682

Heather Wright, K. V. Cashman, Patricia Mothes, Minard L. Hall, A. Ruiz, Jean‐Luc Le Pennec,

Atmospheric and Environmental Gas Dynamics

Research Article| July 01, 2012 Estimating rates of decompression from textures of erupted ash particles produced by 1999–2006 eruptions of Tungurahua volcano, Ecuador Heather M.N. Wright; Heather M.N. Wright 1U.S. Geological Survey, MS 910, 345 Middlefield Road, Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar Katharine V. Cashman; Katharine V. Cashman 2Department of Geological Sciences, 1272 University of Oregon, Eugene, Oregon 97403, USA Search for other works by this author on: GSW Google Scholar Patricia A. Mothes; Patricia A. Mothes 3Instituto Geofìsico, Escuela Politècnica Nacional, Apartado 2759, Quito, Ecuador Search for other works by this author on: GSW Google Scholar Minard L. Hall; Minard L. Hall 3Instituto Geofìsico, Escuela Politècnica Nacional, Apartado 2759, Quito, Ecuador Search for other works by this author on: GSW Google Scholar Andrés Gorki Ruiz; Andrés Gorki Ruiz 3Instituto Geofìsico, Escuela Politècnica Nacional, Apartado 2759, Quito, Ecuador Search for other works by this author on: GSW Google Scholar Jean–Luc Le Pennec Jean–Luc Le Pennec 4IRD, R 163, Laboratoire Magmas et Volcans, 5 rue Kessler, 63038 Clermont-Ferrand cedex, France Search for other works by this author on: GSW Google Scholar Geology (2012) 40 (7): 619–622. https://doi.org/10.1130/G32948.1 Article history received: 21 Oct 2011 rev-recd: 01 Feb 2012 accepted: 06 Feb 2012 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Heather M.N. Wright, Katharine V. Cashman, Patricia A. Mothes, Minard L. Hall, Andrés Gorki Ruiz, Jean–Luc Le Pennec; Estimating rates of decompression from textures of erupted ash particles produced by 1999–2006 eruptions of Tungurahua volcano, Ecuador. Geology 2012;; 40 (7): 619–622. doi: https://doi.org/10.1130/G32948.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Persistent low- to moderate-level eruptive activity of andesitic volcanoes is difficult to monitor because small changes in magma supply rates may cause abrupt transitions in eruptive style. As direct measurement of magma supply is not possible, robust techniques for indirect measurements must be developed. Here we demonstrate that crystal textures of ash particles from 1999 to 2006 Vulcanian and Strombolian eruptions of Tungurahua volcano, Ecuador, provide quantitative information about the dynamics of magma ascent and eruption that is difficult to obtain from other monitoring approaches. We show that the crystallinity of erupted ash particles is controlled by the magma supply rate (MSR); ash erupted during periods of high magma supply is substantially less crystalline than during periods of low magma supply. This correlation is most easily explained by efficient degassing at very low pressures (<<50 MPa) and degassing-driven crystallization controlled by the time available prior to eruption. Our data also suggest that the observed transition from intermittent Vulcanian explosions at low MSR to more continuous periods of Strombolian eruptions and lava fountains at high MSR can be explained by the rise of bubbles through (Strombolian) or trapping of bubbles beneath (Vulcanian) vent-capping, variably viscous (and crystalline) magma. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.