The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén

Lancaster Environment Centre

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The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén. / Castro, Jonathan M.; Cordonnier, Benoit; Tuffen, Hugh et al.
In: Earth and Planetary Science Letters, Vol. 333-334, No. n/a, 17.04.2012, p. 63-69.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Harvard

Castro, JM, Cordonnier, B, Tuffen, H, Tobin, M, Puskar, L, Martin, MC & Bechtel, H 2012, 'The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén', Earth and Planetary Science Letters, vol. 333-334, no. n/a, pp. 63-69. https://doi.org/10.1016/j.epsl.2012.04.024

APA

Castro, J. M., Cordonnier, B., Tuffen, H., Tobin, M., Puskar, L., Martin, M. C., & Bechtel, H. (2012). The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén. Earth and Planetary Science Letters, 333-334(n/a), 63-69. https://doi.org/10.1016/j.epsl.2012.04.024

Vancouver

Castro JM, Cordonnier B, Tuffen H, Tobin M, Puskar L, Martin MC et al. The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén. Earth and Planetary Science Letters. 2012 Apr 17;333-334(n/a):63-69. doi: 10.1016/j.epsl.2012.04.024

Author

Castro, Jonathan M. ; Cordonnier, Benoit ; Tuffen, Hugh et al. / The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén. In: Earth and Planetary Science Letters. 2012 ; Vol. 333-334, No. n/a. pp. 63-69.

Bibtex

@article{7cfbbf0b8a5247bc97a429e5d3428007,

title = "The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volc{\'a}n Chait{\'e}n",

abstract = "Explosive volcanic eruptions of silcic magma often evolve towards non-explosive emissions of lava. The mechanisms underlying this transition remain unclear, however, a widely cited idea holds that shear-induced magma fragmentation plays a critical role by fostering volatile loss from fragmentary magma and through ash-filled cracks termed tuffisite. We test this hypothesis by measuring H2O concentrations within glassy tuffisite from the 2008- rhyolitic eruption at volc{\'a}n Chait{\'e}n, Chile. We show that while H2O concentrations decrease next to tuffisite veins and at the margins of obsidian fragments, the depletions cannot account for the disparity in H2O between explosively and effusively erupted rhyolite. Tuffisite vein lifetimes derived from diffusion modeling (min to hrs) imply degassing rates that are too slow to effectively degas magma, unless the magma was entirely fragmented to mm or smaller particles. This level of brecciation may locally develop near conduit margins, but is unrealistic for entire conduits. The primary role of melt fracturing may therefore be to provide gas-escape pathways for more efficient degassing of permeable vesicularmagma in the conduit interior.",

keywords = "magma degassing, magma fracture, explosive-effusive transition, rhyolitic volcanism, tuffisite, chaiten, tuffisites, shear fragmentation, conduit dynamics",

author = "Castro, {Jonathan M.} and Benoit Cordonnier and Hugh Tuffen and Mark Tobin and Liljana Puskar and Martin, {Michael C.} and Hans Bechtel",

year = "2012",

month = apr,

day = "17",

doi = "10.1016/j.epsl.2012.04.024",

language = "English",

volume = "333-334",

pages = "63--69",

journal = "Earth and Planetary Science Letters",

issn = "0012-821X",

publisher = "Elsevier Science B.V.",

number = "n/a",

}

RIS

TY - JOUR

T1 - The role of melt-fracture degassing in defusing explosive rhyolite eruptions at volcán Chaitén

AU - Castro, Jonathan M.

AU - Cordonnier, Benoit

AU - Tuffen, Hugh

AU - Tobin, Mark

AU - Puskar, Liljana

AU - Martin, Michael C.

AU - Bechtel, Hans

PY - 2012/4/17

Y1 - 2012/4/17

N2 - Explosive volcanic eruptions of silcic magma often evolve towards non-explosive emissions of lava. The mechanisms underlying this transition remain unclear, however, a widely cited idea holds that shear-induced magma fragmentation plays a critical role by fostering volatile loss from fragmentary magma and through ash-filled cracks termed tuffisite. We test this hypothesis by measuring H2O concentrations within glassy tuffisite from the 2008- rhyolitic eruption at volcán Chaitén, Chile. We show that while H2O concentrations decrease next to tuffisite veins and at the margins of obsidian fragments, the depletions cannot account for the disparity in H2O between explosively and effusively erupted rhyolite. Tuffisite vein lifetimes derived from diffusion modeling (min to hrs) imply degassing rates that are too slow to effectively degas magma, unless the magma was entirely fragmented to mm or smaller particles. This level of brecciation may locally develop near conduit margins, but is unrealistic for entire conduits. The primary role of melt fracturing may therefore be to provide gas-escape pathways for more efficient degassing of permeable vesicularmagma in the conduit interior.

AB - Explosive volcanic eruptions of silcic magma often evolve towards non-explosive emissions of lava. The mechanisms underlying this transition remain unclear, however, a widely cited idea holds that shear-induced magma fragmentation plays a critical role by fostering volatile loss from fragmentary magma and through ash-filled cracks termed tuffisite. We test this hypothesis by measuring H2O concentrations within glassy tuffisite from the 2008- rhyolitic eruption at volcán Chaitén, Chile. We show that while H2O concentrations decrease next to tuffisite veins and at the margins of obsidian fragments, the depletions cannot account for the disparity in H2O between explosively and effusively erupted rhyolite. Tuffisite vein lifetimes derived from diffusion modeling (min to hrs) imply degassing rates that are too slow to effectively degas magma, unless the magma was entirely fragmented to mm or smaller particles. This level of brecciation may locally develop near conduit margins, but is unrealistic for entire conduits. The primary role of melt fracturing may therefore be to provide gas-escape pathways for more efficient degassing of permeable vesicularmagma in the conduit interior.

KW - magma degassing

KW - magma fracture

KW - explosive-effusive transition

KW - rhyolitic volcanism

KW - tuffisite

KW - chaiten

KW - tuffisites

KW - shear fragmentation

KW - conduit dynamics

UR - http://www.scopus.com/inward/record.url?scp=84861172100&partnerID=8YFLogxK

U2 - 10.1016/j.epsl.2012.04.024

DO - 10.1016/j.epsl.2012.04.024

M3 - Journal article

AN - SCOPUS:84861172100

VL - 333-334

SP - 63

EP - 69

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

SN - 0012-821X

IS - n/a

ER -

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