Fragmentation and Plinian eruption of crystallizing basaltic magma

Fluid dynamic induced break-up during volcanic eruptions

“…The onset of a yield stress has been reported to occur from particle concentrations of ~0.25–0.55 vol.%; however, this value depends on the particle size and aspect ratio 49 . A recent experimental study 15 has shown that the presence of crystals promotes brittle fracture during filament extension. This was due to non-Newtonian effects at high deformation rates.…”

“…For less silicic melts such as basalt, kimberlite and carbonatite (with viscosities of ⪅10 3 Pa ·s), fragmentation via crossing the glass transition requires very high strain rates >10 4 s −1 . Such strain rates are not observed during terrestrial eruption of low-viscosity melts and therefore theories developed for the fragmentation of silicic systems remain unrealistic 15,16 . Fragmentation of low-viscosity melts must occur by a fundamentally different process—fluid dynamic induced break-up—where magma is stretched and pulled apart to form pyroclasts 2,16–19 .…”

Magma fragmentation in highly explosive basaltic eruptions induced by rapid crystallization

“…where crystallisation has been assumed either to be constant 30 or at equilibrium 11 . Recent results demonstrate that disequilibrium crystallisation plays a fundamental role in magma dynamics within the conduit 12 , but syn-eruptive disequilibrium crystallisation has not yet been considered for basaltic explosive volcanism 11,30 .…”

Basaltic dyke eruptions at Piton de La Fournaise: characterization of the eruptive products with implications for reservoir conditions, conduit processes and eruptive dynamics

“…However, post-fragmentation effects can obliterate the primary signature of the magma, especially during high intensity lava fountain activities (e.g. Mangan and Cashman 1996;Stovall et al 2011Stovall et al , 2012Parcheta et al 2013;Moitra et al 2013Moitra et al , 2018Kawabata et al 2015;Lindoo et al 2016Lindoo et al , 2017. Piton de la Fournaise (PdF) is one of the most active volcanoes in the world in term of eruption frequency but it frequently exhibits low intensity Hawaiian to Strombolian-style activities, allowing efficient and fast natural quenching of the eruptive products that are not significantly modified by postfragmentation expansion phenomena.…”