Publications associées à Gaz volcaniques

Biomass screening for syngas production by flash photopyrolysis

Hubert Girault, Mathieu Soutrenon, Wanderson Oliveira Da Silva

A few seconds flash photopyrolysis is used as efficient screening tool for the investigation of selected biomass in producing syngas, hydrogen and biochar. This innovative approach allowed rapid pyrolysis of the biomass, which was followed by a precise gas ...

Royal Soc Chemistry2024

The influence of water-saturation on the strength of volcanic rocks and the stability of lava domes

Marie Estelle Solange Violay, Michael Heap

The rocks forming a volcanic edifice or dome are typically saturated or partially-saturated with water. However, most experiments aimed at better understanding the mechanical behaviour of volcanic rocks have been performed on dry samples, and therefore mos ...

2023

Novel low-temperature fiber sensing technique using Brillouin scattering in gas

Luc Thévenaz, Yuting Yang, Marcelo Alfonso Soto Hernandez

Brillouin scattering in gases shows the unique property to offer an enhanced temperature sensitivity at very low temperatures. This attractive solution for cryogenic systems is justified theoretically and validated experimentally. ...

Optica Publishing Group2023

The Permeability of Porous Volcanic Rock Through the Brittle-Ductile Transition

Marie Estelle Solange Violay, Corentin Jean-Marie Rémi Noël, Gabriel Gérard Dominique Meyer, Michael Heap

The permeability of volcanic rock controls the distribution of pore fluids and pore fluid pressure within a volcanic edifice, and is therefore considered to influence eruptive style and volcano deformation. We measured the porosity and permeability of a po ...

2022

Year-round trace gas measurements in the central Arctic during the MOSAiC expedition

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

Despite the key role of the Arctic in the global Earth system, year-round in-situ atmospheric composition observations within the Arctic are sparse and mostly rely on measurements at ground-based coastal stations. Measurements of a suite of in-situ trace g ...

2022

Taking the pulse of volcanic eruptions using plagioclase glomerocrysts

Anders Meibom, Stéphane Laurent Escrig, Anders McCarthy, Pierre Vonlanthen

Crystallization timescales in subvolcanic systems and the consequences of interaction between ascending magmas and gases remain largely unconstrained, as do links between these processes and monitoring signals at restless volcanoes. We apply diffusion chro ...

ELSEVIER2020

Three-dimensional radiative transfer effects on airborne and ground-based trace gas remote sensing

Alexis Berne, Dominik Brunner, Thomas Wagner

Air mass factors (AMFs) are used in passive trace gas remote sensing for converting slant column densities (SCDs) to vertical column densities (VCDs). AMFs are traditionally computed with 1D radiative transfer models assuming horizontally homogeneous condi ...

2020

Deciphering Iron-Dependent Activity in Oxygen Evolution Catalyzed by Nickel-Iron Layered Double Hydroxide

Xile Hu, Lichen Bai, Seunghwa Lee

Nickel iron oxyhydroxide is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium. Whereas the presence of Fe ions is essential to the high activity, the functions of Fe are currently under debate. Using oxygen isotope labeling ...

Wiley-VCH Verlag GmbH2020

Plagioclase Glomerocrysts: taking the pulse of volcanic eruptions

Anders Meibom, Stéphane Laurent Escrig, Anders McCarthy

Volcanic eruptions result from complex interplay of magmatic processes including the ascent and storage of magma in the crust, volatile exsolution and crystallization. The dynamics of crystallization in shallow subvolcanic systems and the consequences of i ...

2019

Distributed hydrogen monitoring with phase-sensitive optical time-domain reflectometry

Luc Thévenaz, Li Zhang

We propose a distributed hydrogen sensing system based on ϕ-OTDR and a novel coating configuration with fiber adhesively bonding to palladium foils. An ultra-high sensitivedistributed hydrogen sensing with 5 cm spatial resolution is demonstrated ...

Optical Society of America2018

From rock to magma and back again: The evolution of temperature and deformation mechanism in conduit margin zones

Marie Estelle Solange Violay, Michael Heap

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 explo ...

Elsevier2017

Short magmatic residence times of quartz phenocrysts in Patagonian rhyolites associated with Gondwana breakup

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner, Susanne Seitz

A key parameter in the study of magma evolution is the time scale on which magmatic processes occur. Using nanoscale secondary ion mass spectrometry (NanoSIMS), SIMS, and cathodoluminescence (CL) analyses, we have measured titanium (Ti) diffusion profiles ...

Geological Society of America2016

Tubular gas preconcentrators based on inkjet printed micro-hotplates on foil

Nico de Rooij, Danick Briand, El Hadji Malick Camara

This paper presents the design and implementation of a foil gas preconcentrator (FGP) based on a gold micro-hotplate inkjet printed on a polyimide (PI) substrate. The device is made on flexible foil using printing whereas all preconcentrators seen in liter ...

Elsevier2016

Multiphase-Field Modeling of Micropore Formation in Metallic Alloys

Michel Rappaz, Alain Jacot, Hossein Meidani

A 3D phase-field (PhF) model has been developed to study the formation of micropores constrained to grow within a well-developed solid network. The model accounts for the equilibrium condition at triple (solid-liquid-pore) lines and the partitioning of dis ...

Springer Verlag2015

Dike emplacement at Bardarbunga, Iceland, induces unusual stress changes, caldera deformation, and earthquakes

Nahid Mohajeri Pour Rayeni

A 45-km-long regional dike was emplaced over a period of 2 weeks in August 2014 at the boundary between the East and North Volcanic Zones in Iceland. This is the first regional dike emplacement in Iceland monitored with modern geophysical networks, the imp ...

Springer Verlag2014

Four-dimensional distribution of the 2010 Eyjafjallajokull volcanic cloud over Europe observed by EARLINET

Valentin Simeonov, Ilya Serikov, Ivan Videnov Grigorov, Xiao Wang, Frank Rüdiger Wagner, Valentin Mitev

The eruption of the Icelandic volcano Eyjafjallajokull in April-May 2010 represents a "natural experiment" to study the impact of volcanic emissions on a continental scale. For the first time, quantitative data about the presence, altitude, and layering of ...

Copernicus GmbH2013

A four-dimensional X-ray tomographic microscopy study of bubble growth in basaltic foam

Understanding the influence of bubble foams on magma permeability and strength is critical to investigations of volcanic eruption mechanisms. Increasing foam porosity decreases strength, enhancing the probability of an eruption. However, higher porosities ...

Nature Publishing Group2012

Diffusive-type of double diffusion in lakes - a review

Alfred Johny Wüest, Martin Schmid

This chapter is a contribution in honour of Gerhard H Jirka, who has been fascinated by the amazing variety of small-scale structures that nature surprises us with, particularly in stratified natural waters. Here, we focus on the diffusive regime of double ...

CRC Press2012

Vertical distribution of the different types of aerosols in the stratosphere: Detection of solid particles and analysis of their spatial variability

Quentin Bourgeois

Stratospheric aerosols play a significant role in stratospheric chemistry. In the past, it was assumed that only liquid droplets are present in the stratosphere. Nevertheless, a few lidar measurements have shown that sudden enhancement of aerosol content i ...

2008

Photoacoustic spectroscopy for multi-gas sensing using near infrared lasers

Jean-Philippe Besson

Photoacoustic spectroscopy is a widely recognised technique to measure trace gases at parts-per-million (ppm) or parts-per-billion (ppb) level using semiconductor laser in the near infrared range. This technique is based on the generation of an acoustic wa ...

EPFL2006