Outputs (668)

Outgassing from Open and Closed Magma Foams (2017)
Journal Article

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.

From rock to magma and back again: The evolution of temperature and deformation mechanism in conduit margin zones (2017)
Journal Article

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 strength of heterogeneous volcanic rocks: A 2D approximation (2016)
Journal Article

Volcanic rocks typically contain heterogeneities in the form of crystals and pores. We investigate here the influence of such heterogeneity on the strength of volcanic rocks using an elastic damage mechanics model in which we numerically deform two-d... Read More about The strength of heterogeneous volcanic rocks: A 2D approximation.

Dynamic elastic moduli during isotropic densification of initially granular media (2016)
Journal Article

The elastic properties of homogeneous, isotropic materials are well constrained. However, in heterogeneous and evolving materials, these essential properties are less well-explored. During sintering of volcanic ash particles by viscous processes as w... Read More about Dynamic elastic moduli during isotropic densification of initially granular media.

Thermal vesiculation during volcanic eruptions (2015)
Journal Article

Terrestrial volcanic eruptions are the consequence of magmas ascending to the surface of the Earth. This ascent is driven by buoyancy forces, which are enhanced by bubble nucleation and growth (vesiculation) that reduce the density of magma1. The dev... Read More about Thermal vesiculation during volcanic eruptions.

The feasibility of vitrifying a sandstone enclosure in the British Iron Age (2015)
Journal Article

Iron Age structures with evidence for having been subjected to high temperatures have been identified throughout Europe. The thermal conditions that must have yielded such evidence of alteration remain enigmatic, especially for the case of high-silic... Read More about The feasibility of vitrifying a sandstone enclosure in the British Iron Age.

Eruption and emplacement timescales of ignimbrite super-eruptions from thermo-kinetics of glass shards (2015)
Journal Article

Super-eruptions generating hundreds of cubic kilometers of pyroclastic density currents are commonly recorded by thick, welded and lava-like ignimbrites. Despite the huge environmental impact inferred for this type of eruption, little is yet known ab... Read More about Eruption and emplacement timescales of ignimbrite super-eruptions from thermo-kinetics of glass shards.

Volcanic sintering: Timescales of viscous densification and strength recovery (2013)
Journal Article

[1] Sintering and densification are ubiquitous processes influencing the emplacement of both effusive and explosive products of volcanic eruptions. Here we sinter ash‐size fragments of a synthetic National Institute of Standards and Technology viscos... Read More about Volcanic sintering: Timescales of viscous densification and strength recovery.

Effect of terminal chain length on the helical twisting power in achiral bent-core molecules doped in a cholesteric liquid crystal (2018)
Journal Article

We prepared a homologous series of achiral bent-core (BC) liquid crystals with different terminal alkoxy chain lengths, n (BC-n), and evaluated the helical twisting power (HTP) of the BC-n doped in a cholesteric liquid crystal. The BC-n molecules wit... Read More about Effect of terminal chain length on the helical twisting power in achiral bent-core molecules doped in a cholesteric liquid crystal.

Microstructural and petrophysical properties of the Permo-Triassic sandstones (Buntsandstein) from the Soultz-sous-Forêts geothermal site (France) (2017)
Journal Article

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).

Does an inter-flaw length control the accuracy of rupture forecasting in geological materials? (2017)
Journal Article

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?.

Time-dependent permeability evolution in compacting volcanic fracture systems and implications for gas overpressure (2017)
Journal Article

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.

Local geology controlled the feasibility of vitrifying Iron Age buildings (2017)
Journal Article

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.

Closing an open system: Pore pressure changes in permeable edifice rock at high strain rates (2016)
Journal Article

A permeable or open system will react as a closed system if the rocks implicated are deformed on a timescale that precludes fluid movement. Closed system (“undrained”) deformation therefore leads to a failure mode dependent change in pore pressure: m... Read More about Closing an open system: Pore pressure changes in permeable edifice rock at high strain rates.

Conduit margin heating and deformation during the AD 1886 basaltic Plinian eruption at Tarawera volcano, New Zealand (2016)
Journal Article

During explosive eruptions, a suspension of gas and pyroclasts rises rapidly within a conduit. Here, we have analysed textures preserved in the walls of a pyroclastic feeder dyke of the AD 1886 Tarawera basaltic Plinian fissure eruption. The samples... Read More about Conduit margin heating and deformation during the AD 1886 basaltic Plinian eruption at Tarawera volcano, New Zealand.

Heterogeneity: The key to failure forecasting (2015)
Journal Article

Elastic waves are generated when brittle materials are subjected to increasing strain. Their number and energy increase non-linearly, ending in a system-sized catastrophic failure event. Accelerating rates of geophysical signals (e.g., seismicity and... Read More about Heterogeneity: The key to failure forecasting.

Spine growth and seismogenic faulting at Mt. Unzen, Japan (2015)
Journal Article

The concluding episode of activity during the recent eruption of Mt. Unzen (October 1994 to February 1995) was characterized by incremental spine extrusion, accompanied by seismicity. Analysis of the seismic record reveals the occurrence of two domin... Read More about Spine growth and seismogenic faulting at Mt. Unzen, Japan.

Nonisothermal viscous sintering of volcanic ash (2014)
Journal Article

Volcanic ash is often deposited in a hot state. Volcanic ash containing glass, deposited above the glass transition interval, has the potential to sinter viscously both to itself (particle‐particle) and to exposed surfaces. Here we constrain the kine... Read More about Nonisothermal viscous sintering of volcanic ash.

Continuum percolation of polydisperse rods in quadrupole fields: Theory and simulations (2018)
Journal Article

We investigate percolation in mixtures of nanorods in the presence of external fields that align or disalign the particles with the field axis. Such conditions are found in the formulation and processing of nanocomposites, where the field may be elec... Read More about Continuum percolation of polydisperse rods in quadrupole fields: Theory and simulations.

Shear banding in large amplitude oscillatory shear (LAOStrain and LAOStress) of soft glassy materials (2018)
Journal Article

We study theoretically shear banding in soft glassy materials subject to large amplitude time-periodic shear flows, considering separately the protocols of large amplitude oscillatory shear strain, large amplitude square or triangular or sawtooth str... Read More about Shear banding in large amplitude oscillatory shear (LAOStrain and LAOStress) of soft glassy materials.