Publications related to Large low-shear-velocity provinces

Composition and Pressure Effects on Partitioning of Ferrous Iron in Iron-Rich Lower Mantle Heterogeneities

Philippe Gillet, Marco Cantoni, James Badro, Susannah McGregor Dorfman, Farhang Nabiei, Charles-Edouard Boukaré

Both seismic observations of dense low shear velocity regions and models of magma ocean crystallization and mantle dynamics support enrichment of iron in Earth’s lowermost mantle. Physical properties of iron-rich lower mantle heterogeneities in the modern ...

2021

The Effects of Planetary and Stellar Parameters on Brittle Lithospheric Thickness

Marie Estelle Solange Violay, Michael Heap

The thicknesss of the brittle lithosphere—the outer portion of a planetary body that fails via fracturing— plays a key role in the geological processes of that body. The properties of both a planet and its host star can influence that thickness, and the po ...

2021

Blocked radiative heat transport in the hot pyrolitic lower mantle

James Badro, Farhang Nabiei, Hélène Marie Piet

The heat flux across the core-mantle boundary (Q(CMB)) is the key parameter to understand the Earth's thermal history and evolution. Mineralogical constraints of the Q(CMB) require deciphering contributions of the lattice and radiative components to the th ...

ELSEVIER2020

Effects of composition and pressure on electronic states of iron in bridgmanite

Arnaud Magrez, Philippe Gillet, Susannah McGregor Dorfman

Electronic states of iron in the lower mantle's dominant mineral, (Mg,Fe,Al)(Fe,Al,Si)O-3 bridgmanite, control physical properties of the mantle including density, elasticity, and electrical and thermal conductivity. However, the determination of electroni ...

MINERALOGICAL SOC AMER2020

Convection in Lakes

Alfred Johny Wüest, Damien Bouffard

Lakes and other confined water bodies are not exposed to tides, and their wind forcing is usually much weaker compared to ocean basins and estuaries. Hence, convective processes are often the dominant drivers for shaping mixing and stratification structure ...

2019

Composition of the low seismic velocity E ′ layer at the top of Earth's core

James Badro

Using ab initio simulations on Fe-Ni-S-C-O-Si liquids, we constrain the origin and composition of the low-velocity layer E′ at the top of Earth's outer core. We find that increasing the concentration of any light element always increases velocity and so a ...

2017

From 2D to 3D Characterization of Materials Subjected to Extreme Pressure and Temperature Conditions

Farhang Nabiei

Planetesimal were the first planetary objects to form in the solar system, which later grew to make the proto-planets. Most of these bodies were differentiated as a result of internal heating. Several differentiated bodies have, then, been accreted followi ...

EPFL2017

The importance of mantle wedge heterogeneity to subduction zone magmatism and the origin of EM1

Stéphane Laurent Escrig

The composition of the convecting asthenospheric mantle that feeds the mantle wedge can be investigated via rear-arc lavas that have minimal slab influence. This "ambient mantle wedge" composition (the composition of the wedge prior to the addition of a sl ...

Elsevier2017

Radial localization of edge modes in Alcator C-Mod pedestals using optical diagnostics

Christian Gabriel Theiler

Dedicated experiments in ion cyclotron range heated enhanced D-alpha (EDA) H-mode and I-mode plasmas have been performed on Alcator C-Mod to identify the location of edge fluctuations inside the pedestal and to determine their plasma frame phase velocity. ...

Institute of Physics2017

Chemical Characterisation of Deep Earth Reservoirs

Hélène Marie Piet

Seismic imaging of the internal Earth has emphasized the inhomogeneity of its mantle. This interface layer of nearly 3000 km surrounding the central metallic core conducts heat released from the latter, which played a significant role in shaping the actual ...

EPFL2016

Primordial metallic melt in the deep mantle

Susannah McGregor Dorfman

Seismic tomography models reveal two large low shear velocity provinces (LLSVPs) that identify large-scale variations in temperature and composition in the deep mantle. Other characteristics include elevated density, elevated bulk sound speed, and sharp bo ...

Amer Geophysical Union2016

Spin and valence dependence of iron partitioning in Earth's deep mantle

Cécile Hébert, Philippe Gillet, Marco Cantoni, Farhang Nabiei, James Badro, Hélène Marie Piet, Teresa Katharina Dennenwaldt

We performed laser-heated diamond anvil cell experiments combined with state-of-the-art electron microanalysis (focused ion beam and aberration-corrected transmission electron microscopy) to study the distribution and valence of iron in Earth's lower mantl ...

National Academy of Sciences2016

Parameterization of bottom mixed layer and logarithmic layer heights in central Lake Erie

Damien Bouffard

The bottom boundary layer in lakes lies directly above the sediments and influences both hydrodynamic processes and biogeochemical fluxes. Several parameter-based models have been developed to predict the boundary layer characteristics, but the relative ac ...

Elsevier Sci Ltd2015

Absolute and convective instabilities of heated coaxial jet flow

Gioele Mariano Nicolò Balestra, Leonhard Kleiser

This study investigates the inviscid, linear spatio-temporal stability of heated, compressible, and incompressible coaxial jet flows. The influence of the temperature ratio and the velocity ratio between the core jet and the bypass stream on the transition ...

Amer Inst Physics2015

Thermoelasticity of Fe2+-bearing bridgmanite

Matteo Cococcioni, Andrea Floris

We present local density approximation augmented by the Hubbard-type correction calculations of high-temperature elastic properties of bridgmanite with composition (Mg(1-x)Fex2+)SiO3 for 0

Amer Geophysical Union2015

Effect of Fe-enrichment on seismic properties of perovskite and post-perovskite in the deep lower mantle

Susannah McGregor Dorfman

Recent experimental measurements of the equation of state of perovskites and post-perovskites in the (Mg,Fe)SiO3 and (Mg,Fe,Al)(Fe,Al,Si)O-3 systems over a wide range of iron contents are used to constrain the effects of Fe and Al on density and bulk modul ...

Oxford University Press2014

A seismologically consistent compositional model of Earth's core

James Badro

Earth's core is less dense than iron, and therefore it must contain "light elements," such as S, Si, O, or C. We use ab initio molecular dynamics to calculate the density and bulk sound velocity in liquid metal alloys at the pressure and temperature condit ...

National Academy of Sciences2014

Competition of the primary and peritectic phases in hypoperitectic Cu-Sn alloys solidified at low speed in a diffusive regime

Michel Rappaz, Jean-Daniel Wagnière, Jonas Valloton

Directional solidification experiments on hypoperitectic Cu-Sn alloys have been performed at very low velocity in a high thermal gradient to ensure planar front growth of both phases. The diameter of the sample has been reduced to 500 mu m to strongly redu ...

Elsevier2012

Electrostatic instabilities, turbulence and fast ion interactions in the TORPEX device

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Benoît Labit, Christian Gabriel Theiler, Joaquim Loizu Cisquella, Mario Ludovico Podesta, Francesca Maria Poli, Gennady Plyushchev, Lucia Isabel Federspiel, Kyle Gustafson, Davoud Iraji, Alice Burckel, Stefan Müller

Electrostatic turbulence, related structures and their effect on particle, heat and toroidal momentum transport are investigated in TORPEX simple magnetized plasmas using high-resolution diagnostics, control parameters, linear fluid models and nonlinear nu ...

Institute of Physics2010

Intermittent oxygen flux from the interior into the bottom boundary of lakes as observed by eddy correlation

Alfred Johny Wüest, Bernhard Wehrli

Turbulent oxygen transport from the overlying stratified water column into the bottom boundary layer (BBL) on the slope of a medium-sized lake was investigated using the eddy correlation (EC) technique. The seicheinduced oscillatory flow of the BBL, with a ...

American Society of Limnology and Oceanography2008