All Outputs (104)

Combined effusive-explosive silicic volcanism straddles the multiphase viscous-to-brittle transition (2018)
Journal Article
Wadsworth, F. B., Witcher, T., Vossen, C. E., Hess, K., Unwin, H. E., Scheu, B., …Dingwell, D. B. (2018). Combined effusive-explosive silicic volcanism straddles the multiphase viscous-to-brittle transition. Nature Communications, 9(1), Article 4696. https://doi.org/10.1038/s41467-018-07187-w

Magma is a viscoelastic fluid that can support fracture propagation when local shear stresses are high, or relax and flow when shear stresses are low. Here we present experiments to confirm this using synthetic and natural magmatic liquids across eru... Read More about Combined effusive-explosive silicic volcanism straddles the multiphase viscous-to-brittle transition.

Upscaling permeability in anisotropic volcanic systems (2018)
Journal Article
Farquharson, J. I., & Wadsworth, F. B. (2018). Upscaling permeability in anisotropic volcanic systems. Journal of Volcanology and Geothermal Research, 364, 35-47. https://doi.org/10.1016/j.jvolgeores.2018.09.002

Permeability is an important input to models of shallow magma ascent. It is a property that can exhibit anisotropy in volcanic magmas, rocks and edifices. Here we show that some important features of permeability anisotropy can be captured by a simpl... Read More about Upscaling permeability in anisotropic volcanic systems.

Disclosing the temperature of columnar jointing in lavas (2018)
Journal Article
Lamur, A., Lavallée, Y., Iddon, F. E., Hornby, A. J., Kendrick, J. E., von Aulock, F. W., & Wadsworth, F. B. (2018). Disclosing the temperature of columnar jointing in lavas. Nature Communications, 9(1), Article 1432. https://doi.org/10.1038/s41467-018-03842-4

Columnar joints form by cracking during cooling-induced contraction of lava, allowing hydrothermal fluid circulation. A lack of direct observations of their formation has led to ambiguity about the temperature window of jointing and its impact on flu... Read More about Disclosing the temperature of columnar jointing in lavas.

Experimental sintering of ash at conduit conditions and implications for the longevity of tuffisites (2018)
Journal Article
Gardner, J. E., Wadsworth, F. B., Llewellin, E. W., Watkins, J. M., & Coumans, J. P. (2018). Experimental sintering of ash at conduit conditions and implications for the longevity of tuffisites. Bulletin of Volcanology, 80(3), Article 23. https://doi.org/10.1007/s00445-018-1202-8

Escape of gas from magma in the conduit plays a crucial role in mitigating explosivity. Tuffisite veins—ash-filled cracks that form in and around volcanic conduits—represent important gas escape pathways. Sintering of the ash infill decreases its por... Read More about Experimental sintering of ash at conduit conditions and implications for the longevity of tuffisites.

Microstructural and petrophysical properties of the Permo-Triassic sandstones (Buntsandstein) from the Soultz-sous-Forêts geothermal site (France) (2017)
Journal Article
Heap, M. J., Kushnir, A. R., Gilg, H. A., Wadsworth, F. B., Reuschlé, T., & Baud, P. (2017). Microstructural and petrophysical properties of the Permo-Triassic sandstones (Buntsandstein) from the Soultz-sous-Forêts geothermal site (France). Geothermal Energy, 5(1), Article 26. https://doi.org/10.1186/s40517-017-0085-9

Geothermal projects in the Upper Rhine Graben aim to harness thermal anomalies that have arisen due to hydrothermal circulation within the granitic basement and the overlying Permo-Triassic sedimentary units. We present here a systematic microstructu... Read More about Microstructural and petrophysical properties of the Permo-Triassic sandstones (Buntsandstein) from the Soultz-sous-Forêts geothermal site (France).

Sphere models for pore geometry and fluid permeability in heterogeneous magmas. (2017)
Journal Article
Vasseur, J., & Wadsworth, F. B. (2017). Sphere models for pore geometry and fluid permeability in heterogeneous magmas. Bulletin of Volcanology, 79(11), Article 77. https://doi.org/10.1007/s00445-017-1165-1

The permeability of magmas to percolating fluids plays a role in controlling eruption explosivity. While measurements of volcanic rock permeability abound, comparison of these values with models that relate hydraulic properties to random heterogeneou... Read More about Sphere models for pore geometry and fluid permeability in heterogeneous magmas..

Permeability Evolution in Variably Glassy Basaltic Andesites Measured Under Magmatic Conditions (2017)
Journal Article
Kushnir, A., Martel, C., Champallier, R., & Wadsworth, F. (2017). Permeability Evolution in Variably Glassy Basaltic Andesites Measured Under Magmatic Conditions. Geophysical Research Letters, 44(20), 10,262-10,271. https://doi.org/10.1002/2017gl074042

Heat from inflowing magma may act to seal permeable networks that assist passive outgassing at volcanic conduit margins and in overlying domes, reducing the efficiency of overpressure dissipation. Here we present a study of the evolution of permeabil... Read More about Permeability Evolution in Variably Glassy Basaltic Andesites Measured Under Magmatic Conditions.

Topological inversions in coalescing granular media control fluid-flow regimes (2017)
Journal Article
Wadsworth, F., Vasseur, J., Llewellin, E., Dobson, K., Colombier, M., von Aulock, F., …Dingwell, D. (2017). Topological inversions in coalescing granular media control fluid-flow regimes. Physical Review E, 96(3), Article 033113. https://doi.org/10.1103/physreve.96.033113

Sintering—or coalescence—of viscous droplets is an essential process in many natural and industrial scenarios. Current physical models of the dynamics of sintering are limited by the lack of an explicit account of the evolution of microstructural geo... Read More about Topological inversions in coalescing granular media control fluid-flow regimes.

Stability of volcanic ash aggregates and break-up processes (2017)
Journal Article
Mueller, S. B., Kueppers, U., Ametsbichler, J., Cimarelli, C., Merrison, J. P., Poret, M., …Dingwell, D. B. (2017). Stability of volcanic ash aggregates and break-up processes. Scientific Reports, 7(1), Article 7440. https://doi.org/10.1038/s41598-017-07927-w

Numerical modeling of ash plume dispersal is an important tool for forecasting and mitigating potential hazards from volcanic ash erupted during explosive volcanism. Recent tephra dispersal models have been expanded to account for dynamic ash aggrega... Read More about Stability of volcanic ash aggregates and break-up processes.

Does an inter-flaw length control the accuracy of rupture forecasting in geological materials? (2017)
Journal Article
Vasseur, J., Wadsworth, F. B., Heap, M. J., Main, I. G., Lavallée, Y., & Dingwell, D. B. (2017). Does an inter-flaw length control the accuracy of rupture forecasting in geological materials?. Earth and Planetary Science Letters, 475, 181-189. https://doi.org/10.1016/j.epsl.2017.07.011

Multi-scale failure of porous materials is an important phenomenon in nature and in material physics – from controlled laboratory tests to rockbursts, landslides, volcanic eruptions and earthquakes. A key unsolved research question is how to accurate... Read More about Does an inter-flaw length control the accuracy of rupture forecasting in geological materials?.

Outgassing from Open and Closed Magma Foams (2017)
Journal Article
von Aulock, F. W., Kennedy, B. M., Maksimenko, A., Wadsworth, F. B., & Lavallée, Y. (2017). Outgassing from Open and Closed Magma Foams. Frontiers in Earth Science, 5, Article 46. https://doi.org/10.3389/feart.2017.00046

During magma ascent, bubbles nucleate, grow, coalesce, and form a variably permeable porous network. The reorganization, failing and sealing of bubble walls may contribute to the opening and closing of the volcanic system. In this contribution we cau... Read More about Outgassing from Open and Closed Magma Foams.

A viscous-to-brittle transition in eruptions through clay suspensions (2017)
Journal Article
Schmid, D., Scheu, B., Wadsworth, F. B., Kennedy, B. M., Jolly, A., & Dingwell, D. B. (2017). A viscous-to-brittle transition in eruptions through clay suspensions. Geophysical Research Letters, 44(10), 4806-4813. https://doi.org/10.1002/2017gl073641

Volcanic lakes are often associated with active geothermal circulation, mineral alteration, and precipitation, each of which can complicate the analysis of shallow magma physics, geophysical signals, and chemical signals. The rheology of the lake and... Read More about A viscous-to-brittle transition in eruptions through clay suspensions.

Time-dependent permeability evolution in compacting volcanic fracture systems and implications for gas overpressure (2017)
Journal Article
Farquharson, J. I., Wadsworth, F. B., Heap, M. J., & Baud, P. (2017). Time-dependent permeability evolution in compacting volcanic fracture systems and implications for gas overpressure. Journal of Volcanology and Geothermal Research, 339, 81-97. https://doi.org/10.1016/j.jvolgeores.2017.04.025

Volcanic eruptions are driven by the ascent of volatile-laden magma. The capacity of a volcano system to outgas these volatiles—its permeability—controls the explosive potential, and fractures at volcanic conduit margins play a crucial role in temper... Read More about Time-dependent permeability evolution in compacting volcanic fracture systems and implications for gas overpressure.

Wetting and Spreading of Molten Volcanic Ash in Jet Engines (2017)
Journal Article
Song, W., Lavallée, Y., Wadsworth, F. B., Hess, K., & Dingwell, D. B. (2017). Wetting and Spreading of Molten Volcanic Ash in Jet Engines. Journal of Physical Chemistry Letters, 8(8), 1878-1884. https://doi.org/10.1021/acs.jpclett.7b00417

A major hazard to jet engines posed by volcanic ash is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Here, using the sessile drop method, we study the evolution of the wettability and spreading of volcanic a... Read More about Wetting and Spreading of Molten Volcanic Ash in Jet Engines.

Ash aggregation enhanced by deposition and redistribution of salt on the surface of volcanic ash in eruption plumes (2017)
Journal Article
Mueller, S. B., Ayris, P. M., Wadsworth, F. B., Kueppers, U., Casas, A. S., Delmelle, P., …Dingwell, D. B. (2017). Ash aggregation enhanced by deposition and redistribution of salt on the surface of volcanic ash in eruption plumes. Scientific Reports, 7, Article 45762. https://doi.org/10.1038/srep45762

Interactions with volcanic gases in eruption plumes produce soluble salt deposits on the surface of volcanic ash. While it has been postulated that saturation-driven precipitation of salts following the dissolution of ash surfaces by condensed acidic... Read More about Ash aggregation enhanced by deposition and redistribution of salt on the surface of volcanic ash in eruption plumes.

Size limits for rounding of volcanic ash particles heated by lightning (2017)
Journal Article
Wadsworth, F. B., Vasseur, J., Llewellin, E. W., Genareau, K., Cimarelli, C., & Dingwell, D. B. (2017). Size limits for rounding of volcanic ash particles heated by lightning. Journal of Geophysical Research. Solid Earth, 122(3), 1977-1989. https://doi.org/10.1002/2016jb013864

Volcanic ash particles can be remelted by the high temperatures induced in volcanic lightning discharges. The molten particles can round under surface tension then quench to produce glass spheres. Melting and rounding timescales for volcanic material... Read More about Size limits for rounding of volcanic ash particles heated by lightning.

Sintering of polydisperse viscous droplets (2017)
Journal Article
Wadsworth, F. B., Vasseur, J., Llewellin, E. W., & Dingwell, D. B. (2017). Sintering of polydisperse viscous droplets. Physical Review E, 95(3), Article 033114. https://doi.org/10.1103/physreve.95.033114

Sintering—or coalescence—of compacts of viscous droplets is driven by the interfacial tension between the droplets and the interstitial gas phase. The process, which occurs in a range of industrial and natural settings, such as the manufacture of cer... Read More about Sintering of polydisperse viscous droplets.

From rock to magma and back again: The evolution of temperature and deformation mechanism in conduit margin zones (2017)
Journal Article
Heap, M. J., Violay, M., Wadsworth, F. B., & Vasseur, J. (2017). From rock to magma and back again: The evolution of temperature and deformation mechanism in conduit margin zones. Earth and Planetary Science Letters, 463, 92-100. https://doi.org/10.1016/j.epsl.2017.01.021

Explosive silicic volcanism is driven by gas overpressure in systems that are inefficient at outgassing. The zone at the margin of a volcanic conduit—thought to play an important role in the outgassing of magma and therefore pore pressure changes and... Read More about From rock to magma and back again: The evolution of temperature and deformation mechanism in conduit margin zones.

The evolution of pore connectivity in volcanic rocks (2017)
Journal Article
Colombier, M., Wadsworth, F. B., Gurioli, L., Scheu, B., Kueppers, U., Di Muro, A., & Dingwell, D. B. (2017). The evolution of pore connectivity in volcanic rocks. Earth and Planetary Science Letters, 462, 99-109. https://doi.org/10.1016/j.epsl.2017.01.011

Pore connectivity is a measure of the fraction of pore space (vesicles, voids or cracks) in a material that is interconnected on the system length scale. Pore connectivity is fundamentally related to permeability, which has been shown to control magm... Read More about The evolution of pore connectivity in volcanic rocks.

Local geology controlled the feasibility of vitrifying Iron Age buildings (2017)
Journal Article
Wadsworth, F. B., Heap, M. J., Damby, D. E., Hess, K., Najorka, J., Vasseur, J., …Dingwell, D. B. (2017). Local geology controlled the feasibility of vitrifying Iron Age buildings. Scientific Reports, 7, Article 40028. https://doi.org/10.1038/srep40028

During European prehistory, hilltop enclosures made from polydisperse particle-and-block stone walling were exposed to temperatures sufficient to partially melt the constituent stonework, leading to the preservation of glassy walls called ‘vitrified... Read More about Local geology controlled the feasibility of vitrifying Iron Age buildings.