Eric Breard

Eric Breard
The University of Edinburgh | UoE

PhD

About

37
Publications
14,996
Reads
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727
Citations
Citations since 2017
18 Research Items
596 Citations
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2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
Introduction
Investigate the dynamics of PDCs through large-scale experiments and numerical modeling
Additional affiliations
February 2016 - October 2016
Massey University
Position
  • PhD Student
Education
November 2012 - May 2016
Massey University
Field of study
  • Volcanology
August 2011 - August 2012
September 2010 - July 2012
Université Clermont Auvergne
Field of study
  • volcanology

Publications

Publications (37)
Article
Full-text available
PELE is a large-scale facility for experimental studies of pyroclastic density currents (PDCs). It is used to generate high-energy currents involving 500–6,500 m3 natural volcanic material and air that achieve velocities of 7–30 ms−1, flow thicknesses of 2–4.5 m, and runouts of >35 m. The experimental PDCs are synthesized by a controlled ‘eruption...
Article
Full-text available
One of the most dangerous aspects of explosive volcanism is the occurrence of dilute pyroclastic density currents that move at high velocities of tens to about a hundred of metres per second outwards from volcanic vents. Predicting the runout behaviour of these turbulent flows of hot particles and air is complicated by strong changes in the flow de...
Preprint
Full-text available
For decades scaled analog experiments have improved the understanding of a broad range of multiphase volcanological processes in controlled laboratory environments. Successfully modeled processes include magma flow through magma reservoirs, conduits and sheets, associated crustal deformation, lava flow, volcanic plume dynamics, ash cloud dispersion...
Article
For decades, scaled analog experiments have improved the understanding of a broad range of multiphase volcanological processes in controlled laboratory environments. Successfully modeled processes include magma flow through magma reservoirs, conduits and sheets, associated crustal deformation, lava flow, volcanic plume dynamics, ash cloud dispersio...
Article
Full-text available
Natural geophysical mass flows are among the most complex granular systems and their dynamics are often modified by the presence of an interstitial fluid. Prediction of their runout requires the development of models estimating the solid stresses in these hazardous currents wherein excess pore-fluid pressure can develop. We use discrete element mod...
Article
Full-text available
Pyroclastic surges are lethal hazards from volcanoes that exhibit enormous destructiveness through dynamic pressures of 10 ⁰ –10 ² kPa inside flows capable of obliterating reinforced buildings. However, to date, there are no measurements inside these currents to quantify the dynamics of this important hazard process. Here we show, through large-sca...
Data
This repository contains data presented in the article “Destructiveness of pyroclastic surges controlled by turbulent fluctuations” by E. Brosch, G. Lube, M. Cerminara, T. Esposti-Ongaro, E.C.P. Breard, J. Dufek, B. Sovilla and L. Fullard. The article was published in Nature Communications (https://doi.org/10.1038/s41467-021-27517-9). A readme fil...
Article
Full-text available
The storage of granular materials is a critical process in industry, which has driven research into flow in silos. Varying material properties, such as particle size, can cause segregation of mixtures. This work seeks to elucidate the effects of size differences and determine how using a flow-correcting insert mitigates segregation during silo disc...
Article
Full-text available
Numerous large‐scale geophysical flows propagate with low‐apparent basal friction coefficients, but the source of such phenomenology is poorly known. Motivated by scarce basal friction data from natural flows, we use numerical methods to investigate the interaction of granular flows with their substrate under idealized conditions. Here we investiga...
Article
Full-text available
The incorporation of snow and ice by pyroclastic density currents (PDCs) can generate mixed-avalanches and pose significant hazards at snow-clad volcanoes. Commonly, the poor preservation of these thin deposits, combined with the subtle characteristics of PDC-snow interaction, has limited their recognition in the geological record. A small-volume (...
Article
Full-text available
Pyroclastic density currents (PDCs) are dangerous multiphase flows originating from volcanic eruptions. PDCs cause more than a third of volcanic fatalities globally and, therefore, development of robust PDC hazard models is a priority in volcanology and natural hazard science. However, the complexity of gas–particle interactions inside PDCs, as wel...
Article
Full-text available
Granular flows are found across multiple geophysical environments and include pyroclastic density currents, debris flows, and avalanches, among others. The key to describing transport of these hazardous flows is the rheology of these complex multiphase mixtures. Here we use the multiphase model MFIX in 2-D for concentrated currents to examine the i...
Article
Full-text available
Pyroclastic density currents are highly dangerous ground-hugging currents from volcanoes that cause >50% of volcanic fatalities globally. These hot mixtures of volcanic particles and gas exhibit remarkable fluidity, which allows them to transport thousands to millions of tonnes of volcanic material across the Earth’s surface over tens to hundreds o...
Article
Full-text available
Geophysical fluid-granular flows, such as pyroclastic currents and debris flows, owe much of their runout and hazard behavior to the occurrence and time-variant decay of a flow-internal fluid pore pressure. However, modeling the effects of fluid pore pressure to forecast hazards is challenging because a unified method in Earth Sciences to quantitat...
Article
Full-text available
The dynamics of granular flow in a rectangular silo with two symmetrically placed exit openings is investigated using particle image velocimetry (PIV), flow rate measurements and discrete element modelling (DEM). The flow of mustard seeds in a Perspex silo is recorded using a high-speed camera and the resulting image frames are analysed using PIV t...
Article
Full-text available
Pyroclastic density currents (PDCs) are a significant volcanic hazard. However, their dominant transport mechanisms remain poorly understood, in part because of the large variability of PDC types and deposits. Here, we combine field data with experimental and numerical simulations to illuminate the twofold fate of particles settling from an ash clo...
Article
Full-text available
Gravity-driven discharge experiments were performed in a perspex 3D flat bottomed silo which was filled with a granular material, and had a variable discharge orifice size. The granular material used was amaranth seed with an average diameter of 1 mm. Particle Image Velocimetry (PIV) analysis was performed on a high-speed video recording of the dis...
Article
Full-text available
Industrial storage of granular material using silos is common, however, improved understanding of silo flow is needed. Various continuum models attempt to describe the velocity of dense granular flow in silos. Kinematic, and recently, stochastic models, based upon the diffusion of some quantity, perform well when there is a single orifice, and when...
Data
Full-text available
Article
Full-text available
Granular material has the unique ability to transition between solid and liquid-like phases, but quantitative observations of the dynamics involved in this process remain rare. We hypothesize that granular packing of the solid phase has a leading control on this transition. To test this, we visualize the flow transitions that occur during discharge...
Article
Pyroclastic density currents (PDCs) are the most lethal threat from volcanoes. While there are two main types of PDCs (fully turbulent, fully dilute pyroclastic surges and more concentrated pyroclastic flows encompassing non-turbulent to turbulent transport) pyroclastic flows, which are the subject of the present study, are far more complex than di...
Article
Full-text available
Available online 20 August 2016 Editor: T.A. Mather Keywords: Te Maari hydrothermal eruption experimental fragmentation explosive energy ballistics Sudden hydrothermal eruptions occur in many volcanic settings and may include high-energy explosive phases. Ballistics launched by such events, together with ash plumes and pyroclastic density currents,...
Article
Volcanic eruptions are at their most deadly when pyroclastic density currents sweep across landscapes to devastate everything in their path1, 2. The internal dynamics underpinning these hazards cannot be directly observed3. Here we present a quantitative view inside pyroclastic density currents by synthesizing their natural flow behaviour in large-...
Article
Full-text available
The 2012 eruption of Tongariro volcano (New Zealand) produced highly mobile, low-temperature, blast-derived pyroclastic density currents after partial collapse of the western flank of the Upper Te Maari crater. Despite a low volume (340,000 m3), the flows traveled up to 2.5 km from source, covering a total area of 6.1 km2. Along one of the blast ax...
Article
On 6 August, 2012, Upper Te Maari Crater, Tongariro volcano, New Zealand, erupted for the first time in over one hundred years. Multiple vents were activated during the hydrothermal eruption, ejecting blocks up to 2.3 km and impacting ~ 2.6 km of the Tongariro Alpine Crossing (TAC) hiking track. Ballistic impact craters were mapped to calibrate a 3...
Article
Full-text available
The weak geophysical precursors of the 6 August 2012 Te Maari eruption of Mt. Tongariro and a lack of obvious juvenile components in its proximal ballistic deposits imply that the eruption was caused by the sudden decompression of a sealed, hot hydrothermal system. Strong magmatic signals in pre- and post-eruption gas emissions indicate that fresh...
Article
The 6 August 2012 Te Maari eruption produced violent and widespread “cold” Pyroclastic Density Currents (PDCs) following unroofing of the pressurized hydrothermal system. Despite an erupted volume of only ~ 5 x105 m3, and lacking any juvenile component, the 340,000 m3 of PDCs spread over an area of 6.1 km2 and had mobilities that were on the order...
Article
Full-text available
The ballistic ejection of blocks during explosive eruptions constitutes a major hazard near active volcanoes. Fields of ballistic clasts can provide important clues towards quantifying the energy, dynamics and directionality of explosive events, but detailed datasets are rare. During the 6 August 2012 hydrothermal eruption of Upper Te Maari (Tongar...
Article
Central Andean deformation history in southern Peru is recorded in Neogene volcanic units of Ocoña and Cotahuasi canyons that cut across the western Cordillera. Acceleration (<25 Ma) of uplift in the region is reflected in the Neogene epiclastic deposits with interspersed and subsequent rhyolitic ignimbrites between 24.6 and 1.37 Ma. Large-volume (...

Questions

Questions (3)
Question
Hello,
I am looking for experimental and natural data regarding the thermal conductivity (and specific heat capacity) of basaltic deposits, made of ash (and or with lapillis). In particular, having such data versus mixture porosity would be ideal. It has been commonly measured for sandstone for instance.
Any references in mind to direct me to?
Regards,
Eric
Question
Just as a reminder, for a weighted distribution, the Sauter mean = 1/ sum(xi/di).
I am looking for a formula that is like the D32 = median*exp(7/2 * std deviation2) (obtained by cumputing the higher moment of the number distribution); for a size distribution of n particles,  D32 = sum (ni di3) / sum(ni di2)
If one has the full weighted distribution, there is no issue to get the Sauter mean, but I am trying to convert data of median/mean and std deviation (for which there is no published full PSD) into a Sauter mean diameter.
Thank you for the feedback and help.
E.
Question
For instance, if air would be blown downward from an object onto a loadcell, so that the object flies at a given height, the measurement of the air stream over the sensor should be giving the value of the supported weight. Now, is it possible that the measurement of a high frequency loadcell would be lowered in the case where the flying object is now moving at 100 km/h over the sensor? 

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Projects

Projects (3)
Project
Validation of multiphase models (MFIX) against large-scale experiments of pyroclastic density currents
Archived project
This research project aims to explore angle of repose and piling processes during the growth of experimental scoria cones on an instrumented bench. The angle of repose and piling mechanism of granular media, such as scoriaceous deposits, are important controlling factors to understand geometry and geomorpholgy of scoria cones.