Volatile degassing, petrology, and magma dynamics of the Villarrica Lava Lake, Southern Chile

Witter, Jeffrey; Kress, V. C.; Delmelle, Pierre; Stix, John

doi:10.1016/j.jvolgeores.2004.03.002

Cited by 124 publications

(145 citation statements)

References 44 publications

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“…Such a trigger has been described previously as a typical mechanism for the generation of lava fountains and is known in the literature as the "foam collapse model" (Jaupart and Vergniolle, 1989), as opposed to the "rise-speed-dependent model" (Parfitt, 2004), which assumes that an eruption is triggered by syneruptive bubble exsolution accompanying magma rising in the conduit as the volume fraction of bubbles exceeds that of maximum packing. The higher SiO 2 content of lava lake products may be explained by convective conduit dynamics (Witter et al, 2004) during pre-eruptive (years to days) and post-paroxysmal (i.e., days and months after 3 March 2015 eruption) stages, where bubbly flow controls the bursting of lava lake and magma degassing ( Figure 6A). The progressive increase of geophysical signals (i.e., increasing seismicity, thermal anomalies and rising of CO 2 /SO 2 degassing) together with the rise of lava lake and Strombolian activity is interpreted as a higher participation of primitive magma within the conduit and a slug flow type volatile transport on 2 March 2015 ( Figure 6B).…”

Section: Conduit Dynamicsmentioning

confidence: 99%

Tephra From the 3 March 2015 Sustained Column Related to Explosive Lava Fountain Activity at Volcán Villarrica (Chile)

et al. 2018

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Section: Conduit Dynamicsmentioning

confidence: 99%

Tephra From the 3 March 2015 Sustained Column Related to Explosive Lava Fountain Activity at Volcán Villarrica (Chile)

et al. 2018

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“…The magnitude of the involved (over)pressure is calculated by applying Archimedes' principle, which assumes the mass of the fluid displaced (Δρ V in ), times gravity acceleration (g), divided by the (ascending) conduit area. We take the density difference Δρ between degassed (descending) and gas-rich (ascending) magma to range from 70 to 120 kg m À3 [Witter et al, 2004;Huppert and Hallworth, 2007].…”

Section: The Modelmentioning

confidence: 99%

Dynamics of the Mount Nyiragongo lava lake

et al. 2014

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The permanent and presently rising lava lake at Mount Nyiragongo constitutes a major potential geological hazard to the inhabitants of the Virunga volcanic region in the Democratic Republic of Congo (DRC) and Rwanda. Based on two field campaigns in June 2010 and 2011, we estimate the lava lake level from the southeastern crater rim (~400 m diameter) and lava lake area (~46,550 m 2 ), which constrains, respectively, the lava lake volume (~9 × 10 6 m 3 ) and volume flow rate needed to keep the magma in a molten state (0.6 to 3.5 m 3 s À1

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“…The model of plagioclase-melt phase equilibria proposed by Housh and Luhr [1991] has often been used to estimate preeruptive meltwater contents [e.g., Self and King, 1996;Luhr, 2002;Kaneko et al, 2007]. The MELTS model [Ghiorso and Sack, 1995] is also effective in constraining meltwater contents in magmas with anhydrous phenocryst assemblages [e.g., Witter et al, 2004;Larsen, 2006].…”

Section: A21 Phase Equilibrium Relationsmentioning

confidence: 99%

Preeruptive magma viscosity: An important measure of magma eruptibility

Takeuchi

2011

J. Geophys. Res.

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[1] Using a compilation of melt compositions, meltwater contents, temperatures, and phenocryst contents, the preeruptive viscosities under magma reservoir conditions are calculated for 83 erupted magmas. The basaltic-to-rhyolitic magmas have preeruptive viscosities over the range 10 1 to 10 8 Pa s. Although bulk SiO 2 content has often been used as a qualitative measure of preeruptive magma viscosity, the bulk SiO 2 content shows a weak correlation with magma viscosity (correlation coefficient r = 0.5). Because of a wide range of phenocryst contents from 0 to ∼50 vol %, andesitic magmas have viscosities ranging from 10 2 to 10 7 Pa s, which are lower or higher than those of phenocryst-poor rhyolitic magmas with 10 5 to 10 6 Pa s. Focusing on andesitic to rhyolitic magmas, the r between bulk SiO 2 contents and magma viscosities changes to −0.1. In contrast, the melt-only SiO 2 content from a basaltic-to-rhyolitic melt shows a good linear correlation with melt-only viscosity (r = 0.9). Although most of the calculated viscosities of erupted magmas fall below ∼106 Pa s, as consistent with the previous compilation study, this paper describes 20 examples of highly viscous magmas with >106 Pa s, in most cases, composed of mixtures of high-silica rhyolitic melt (75-79 wt % SiO 2 ) and abundant phenocrysts (30-55 vol %). In these highly viscous magmas, 9 examples have erupted following the precursory eruption of less viscous magma, suggesting that precursory dike propagation and conduit formation by the less viscous magma with <10 6 Pa s induced the following eruption of less eruptible, highly viscous magmas.

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Volatile degassing, petrology, and magma dynamics of the Villarrica Lava Lake, Southern Chile

Cited by 124 publications

References 44 publications

Tephra From the 3 March 2015 Sustained Column Related to Explosive Lava Fountain Activity at Volcán Villarrica (Chile)

Tephra From the 3 March 2015 Sustained Column Related to Explosive Lava Fountain Activity at Volcán Villarrica (Chile)

Dynamics of the Mount Nyiragongo lava lake

Preeruptive magma viscosity: An important measure of magma eruptibility

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