eprintid: 10117176
rev_number: 14
eprint_status: archive
userid: 608
dir: disk0/10/11/71/76
datestamp: 2020-12-10 13:07:54
lastmod: 2021-10-28 22:17:36
status_changed: 2020-12-10 13:07:54
type: article
metadata_visibility: show
creators_name: Lavallee, Y
creators_name: Benson, PM
creators_name: Heap, MJ
creators_name: Flaws, A
creators_name: Hess, K-U
creators_name: Dingwell, DB
title: Volcanic conduit failure as a trigger to magma fragmentation
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F57
note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: In the assessment of volcanic risk, it is often assumed that magma ascending at a slow rate will erupt effusively, whereas magma ascending at fast rate will lead to an explosive eruption. Mechanistically viewed, this assessment is supported by the notion that the viscoelastic nature of magma (i.e., the ability of magma to relax at an applied strain rate), linked via the gradient of flow pressure (related to discharge rate), controls the eruption style. In such an analysis, the physical interactions between the magma and the conduit wall are commonly, to a first order, neglected. Yet, during ascent, magma must force its way through the volcanic edifice/structure, whose presence and form may greatly affect the stress field through which the magma is trying to ascend. Here, we demonstrate that fracturing of the conduit wall via flow pressure releases an elastic shock resulting in fracturing of the viscous magma itself. We find that magma fragmentation occurred at strain rates seven orders of magnitude slower than theoretically anticipated from the applied axial strain rate. Our conclusion, that the discharge rate cannot provide a reliable indication of ascending magma rheology without knowledge of conduit wall stability, has important ramifications for volcanic hazard assessment. New numerical simulations are now needed in order to integrate magma/conduit interaction into eruption models.
date: 2012
date_type: published
publisher: SPRINGER
official_url: https://doi.org/10.1007/s00445-011-0544-2
oa_status: green
full_text_type: other
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1440649
doi: 10.1007/s00445-011-0544-2
lyricists_name: Benson, Philip
lyricists_id: PMBEN89
actors_name: Jayawardana, Anusha
actors_id: AJAYA51
actors_role: owner
full_text_status: public
publication: Bulletin of Volcanology
volume: 74
pagerange: 11-13
pages: 3
issn: 1432-0819
citation:        Lavallee, Y;    Benson, PM;    Heap, MJ;    Flaws, A;    Hess, K-U;    Dingwell, DB;      (2012)    Volcanic conduit failure as a trigger to magma fragmentation.                   Bulletin of Volcanology , 74    pp. 11-13.    10.1007/s00445-011-0544-2 <https://doi.org/10.1007/s00445-011-0544-2>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10117176/1/Benson_BullVolc%20Lavallee-conduit%20FNL.pdf