Non-Newtonian rheological law for highly crystalline dome lavas

Lavallée, Yan; Hess, Kai‐Uwe; Cordonnier, B.; Dingwell, Donald B.

doi:10.1130/g23594a.1

Cited by 171 publications

(142 citation statements)

References 28 publications

Supporting

Mentioning

136

Contrasting

Unclassified

Order By: Relevance

“…We present the result of eight simulations, seven using a shear-thinning viscosity relationship (Lavallée et al, 2007), and one using a Newtonian viscosity relationship (Table 3). The solidus pressure and friction angle are the parameters varied in the simulations because all the other main parameters are relatively well constrained.…”

Section: Resultsmentioning

confidence: 99%

“…Although the rheology of crystal-rich lava is reasonably well understood (Lavallée et al, 2007), the rheology of the talus is not well-constrained, and in reality is likely to vary spatially, with burial. For simplicity, we model the deformation of the entire dome (including the talus) as a ductile fluid.…”

Section: Computational Model Lava Properties and Model Set-upmentioning

confidence: 99%

“…Lavallée et al (2007) performed viscosity measurements on crystal-rich lava, resulting in a singular dependence of viscosity on the strainrate regardless of the geochemistry, the crystal content, and up to 25% bubbles. We use the shear-thinning viscosity relationship without yield strength as presented in Lavallée et al (2007) for crystal-rich lava (Eqn. 1),…”

Section: Viscositymentioning

confidence: 99%

“…Our generic dome model uses both a shear-thinning viscosity relationship (Lavallée et al, 2007) and a constant Newtonian viscosity of 3.4x10 12 Pa s. We use a talus angle of repose of 40º, an appropriate intermediate value for the observed slope of the talus on Soufrière Hills Volcano , a conduit radius of 15 metres, a lava density of 2350 kgm -3 , and a solidus pressure of 0.4 MPa, including atmospheric pressure, to model dome growth for four constant extrusion rates (2, 4, 6, and 8 m 3 /s). These simulations provide a generic understanding of how the talus grows and re-adjusts in the models, as well as how extrusion rate variations influence the rate of talus growth.…”

Section: Generic Dome Growth Modelsmentioning

confidence: 99%

“…The free-surfaces of the dome and the core-talus interface are modelled utilising the level-set method, a technique used to trace flow fronts and boundaries without distorting the model space/mesh (Hale et al, 2007). A shear-thinning viscosity relationship for crystal-rich lava presented by Lavallée et al (2007) is used and compared with that of lava behaving in a Newtonian manner.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Modelling the lava dome extruded at Soufrière Hills Volcano, Montserrat, August 2005–May 2006

Hale

Calder²,

Loughlin

et al. 2009

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

During many lava dome-forming eruptions, persistent rockfalls and the concurrent development of a substantial talus apron around the foot of the dome are important aspects of the observed activity. An improved understanding of internal dome structure, including the shape and internal boundaries of the talus apron, is critical for determining when a lava dome is poised for a major collapse and how this collapse might ensue. We consider a period of lava dome growth at the Soufriere Hills dome growth using measured dome volumes and extrusion rates to drive the model and generate the evolving configuration of the dome core and carapace/talus domains. The evolution of the model is compared with the observed rockfall seismicity using event counts and seismic energy parameters, which are used here as a measure of rockfall intensity and hence a first-order proxy for volumes. The range of model-derived volume increments of talus aggraded to the talus slope per recorded rockfall event, approximately 3,000 -13,000 m 3 per rockfall, is high with respect to estimates based on observed events. From this, it is inferred that some of the volumetric growth of the talus apron (perhaps up to 60 -70%) might have occurred in the form of aseismic deformation of the talus, forced by an internal, laterally spreading core. Talus apron growth by this mechanism has not previously been identified, and this suggests that the core, hosting hot gas-rich lava, could have a greater lateral extent than previously considered.3

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Computational Model Lava Properties and Model Set-upmentioning

confidence: 99%

Section: Viscositymentioning

confidence: 99%

Section: Generic Dome Growth Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Modelling the lava dome extruded at Soufrière Hills Volcano, Montserrat, August 2005–May 2006

Hale

Calder²,

Loughlin

et al. 2009

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

show abstract

Dynamics of Strombolian explosions: Inferences from field and laboratory studies of erupted bombs from Stromboli volcano

et al. 2014

View full text Add to dashboard Cite

Strombolian activity is characterized by repeated, low energy, explosions and is named after the volcano where such activity has persisted for around 2000 years, i.e., Stromboli (Aeolian Islands, Italy). Stromboli represents an excellent laboratory where measurements of such explosions can be made from safe, but close, distances. During a field campaign in 2008, two 15 cm diameter bombs were quenched and collected shortly after a normal explosion. The bombs were characterized in terms of their textural, chemical, rheological, and geophysical signatures. The vesicle and crystal size distribution of the samples, coupled with the glass chemistry, enabled us to quantify variations in the degassing history and rheology of the magma resident in the shallow (i.e., in last 250 m of conduit length). The different textural facies observed in these bombs showed that fresh magma was mingled with batches of partially to completely degassed, oxidized, high-crystallinity, high-viscosity, evolved magma. This magma sat at the top of the conduit and played only a passive role in the explosive process. The fresh, microlite-poor, vesiculated batch, however, experienced a response to the explosive event, by undergoing rapid decompression. Integration of geophysical measurements with sample analyses indicates that popular bubble-bursting models may not fit this case. We suggest that the degassed, magma forms a plug, or rheological layer, at the top of the conduit, through which the fresh magma bursts. In this model we need to consider the paradox of a slug ascending too fast through a magma of varying viscosity and yield strength.

show abstract

Seismological analysis of conduit dynamics in fragmentation experiments

Arciniega-Ceballos¹,

Alatorre‐Ibargüengoitia

Scheu

et al. 2014

JGR Solid Earth

View full text Add to dashboard Cite

We simulate gas-burst and volcanic explosions under controlled laboratory conditions inducing fragmentation of volcanic rocks by rapid depressurization. A series of experiments were performed in a shocktube apparatus at room temperature and a pressure range of 4 to 20 MPa using Argon (Ar) gas and, particles or pumice samples of different porosities. The instrumentation of this system with high-precision piezoelectric sensors enabled us to capture elastic waves and to recognize their characteristic signatures. By relating these signals to physical processes in the wave field, we have been able to characterize the conduit mechanism and the source dynamics. We compare and discuss conspicuous features of the waveforms and frequency spectra of these experimental signals with those of volcanic origin. Despite the fact that these signals are different in amplitude (resulting from different scale conditions); our observations indicate that the physical processes that occur during simulated explosions and those that occur during volcanic eruptions yield comparable signatures in their respective records. The effects of the source-receiver configuration and resonance also have significant implications. All this suggests that the physical processes (e.g. pressurization and depressurization of a system) involve a system response that causes similar distinctive effects independent of the system size, reflecting its intrinsic dynamics. These similarities imply that powerful constraints on the source mechanisms of volcanic seismicity can emerge from seismic investigations of experimental simulations of volumetric sources. Such constraints may yield significant advances in the understanding of volcanic conduit dynamics and in the interpretation of seismic unrest at volcanic centers.

show abstract

Non-Newtonian rheological law for highly crystalline dome lavas

Cited by 171 publications

References 28 publications

Modelling the lava dome extruded at Soufrière Hills Volcano, Montserrat, August 2005–May 2006

Modelling the lava dome extruded at Soufrière Hills Volcano, Montserrat, August 2005–May 2006

Dynamics of Strombolian explosions: Inferences from field and laboratory studies of erupted bombs from Stromboli volcano

Seismological analysis of conduit dynamics in fragmentation experiments

Contact Info

Product

Resources

About