DOI: 10.1016/j.epsl.2020.116637
论文题名: Convective tipping point initiates localization of basaltic fissure eruptions
作者: Jones T.J. ; Llewellin E.W.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 553 语种: 英语
中文关键词: eruption longevity
; excess degassing
; exchange flow
; Hawaiian eruptions
; magma convection
英文关键词: Geology
; Mathematical models
; Buoyancy-driven exchange flows
; Conceptual model
; Hazard management
; Parameter spaces
; Plumbing Systems
; Quantitative frameworks
; Thermally driven
; Viscous fingering
; Reynolds number
; atmospheric convection
; degassing
; fissure
; lava flow
; magma assimilation
; volcanic eruption
; Hawaii [United States]
; United States
英文摘要: Basaltic fissure eruptions may evolve rapidly and unpredictably complicating hazard management. Localization of an elongate fissure to one or more focused vents may take days to months, and depends on fluid dynamic processes, such as thermally-driven viscous fingering, in the sub-volcanic plumbing system. However, fluid dynamics in a dyke geometry are poorly understood. We perform scaled analogue experiments to investigate convective magma exchange flow within a dyke-like conduit, and discover flow regimes ranging from chaotic mingling to stable, well-organized exchange, over the parameter space relevant for natural eruptions. Experiments are scaled via the Grashof number Gr, which is a Reynolds number for buoyancy-driven exchange flows. We propose that chaotic exchange at high Gr hinders thermally-driven localization by suppressing viscous fingering, whereas flow organization at low Gr enhances localization. Consequently, progressive decrease in Gr through increasing magma viscosity or decreasing dyke width pushes a fissure eruption towards a tipping point that results in rapid localization. Our findings indicate that current conceptual models for magma flow in a dyke require revision to account for this convective tipping point, and provide a quantitative framework for understanding the evolution of fissure eruptions. © 2020 The Author(s) Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165534
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, L69 3GP, United Kingdom; Department of Earth Sciences, Durham University, South Road, Durham, DH1 3LE, United Kingdom
Recommended Citation:
Jones T.J.,Llewellin E.W.. Convective tipping point initiates localization of basaltic fissure eruptions[J]. Earth and Planetary Science Letters,2021-01-01,553