ISTerre - Institut des Sciences de la Terre

Publication list

Renaud DEGUEN — 2019-10-10T09:28:21Z

Morison A., Labrosse S., Deguen R., Alboussière T., Timescale of compositional overturn in a magma ocean cumulate. accepted for publication in Earth and Planetary Sciences Letters.

Menaut R., Corre Y., Huguet L., Le Reun T., Alboussière T., Bergman M., Deguen R., Labrosse S., and Moulin M., Experimental study of convection in the compressible regime, Phys. Rev. Fluids, 4, 033502.

Lherm V. & Deguen R., Small-Scale Metal/Silicate Equilibration During Core Formation : The Influence of Stretching Enhanced Diffusion on Mixing, Journal of Geophysical Research : Solid Earth, 123, https://doi.org/10.1029/2018JB016537.

Deguen R., Alboussière T., Labrosse S., Double-diffusive translation of Earth's inner core, Geophysical Journal International, 214, 88 – 107, 2018.

Labrosse S., Morison A., Deguen R., Alboussière T., Rayleigh-Bénard convection with a phase change at either or both horizontal boundaries, Journal of Fluid Mechanics, 846, 5–36, 2018.

Landeau M., Olson P., Deguen R., Hirsh B.H., Core merging and stratification following giant impact, Nature Geoscience, 9, 786-789, 2016.

Huguet L., Alboussière T., Bergman M.I., Deguen R., Labrosse S., Lesoeur G., Structure of a mushy layer under hypergravity with implications for Earth's inner core, Geophysical Journal International, 204, 1729-1755, 2016.

Lincot A., Cardin P., Deguen R., Merkel S., Multiscale model of global inner-core
anisotropy induced by hcp alloy plasticity, Geophysical Research Letters, 43, 1084-1091, 2016.

Lasbleis M., Deguen R., Cardin, P., & Labrosse, S., Inner Core dynamics induced by the Lorentz force. Geophysical Journal International. Geophys. J. Int., 202, 548–563, 2015.

Olson, P., Deguen R., Rudolph, M. & Zhong, S., Core evolution driven by mantle global circulation. Physics of the Earth and Planetary Interiors, 243, 44–55, 2015.

Lasbleis M., & Deguen R., Building a regime diagram for Earth's inner core. Physics of the Earth and Planetary Interiors, 247, 80–93, 2015.

Deguen R., Olson, P. & Reynolds E., F-layer formation in the outer core with asymmetric inner core growth. C. R. Geoscience, 346 (5), 101-109, 2014.

Lincot A., Deguen R., Merkel S. & Cardin P. Forward Model of Seismic Anisotropy in the Earth's Inner Core. C. R. Geoscience, 346 (5), 148-157, 2014.

Landeau M., Deguen R. & Olson P. Experiments on the fragmentation of a buoyant liquid volume in another liquid. Journal of Fluid Mechanics, 749 :478–518, 2014.

Deguen R., Landeau M. & Olson P. Turbulent metal-silicate mixing, fragmentation, and equilibration in magma oceans. Earth and Planetary Science Letters, 391(0) :274– 287, 2014.

Deguen R. Thermal convection in a spherical shell with melting/freezing at its boundaries. Journal of Earth Science, 24, 669-682, 2013.

Deguen R., Alboussière T. & Cardin P. Convection in Earth's inner core with phase change at its boundary. Geophysical Journal International, 194(3) :1310–1334, 2013.

Olson P. L., Deguen R., Hinnov L. A. & Zhong S. Controls on geomagnetic reversals and core evolution by mantle convection in the Phanerozoic Physics of the Earth and Planetary Interiors, 214, 87-103, 2012.

Alboussière T. & Deguen R. Asymmetric Dynamics of the Inner Core and Impact on the Outer Core. Journal of Geodynamics, 61, 172-182, 2012.

Olson P. & Deguen R. Eccentricity of the geomagnetic dipole caused by lopsided inner core growth. Nature Geoscience, 5, 565–569, 2012.

Deguen R. Structure and dynamics of Earth's inner core. Earth and Planetary Science Letters - Frontiers article, 333–334, 211–225, 2012.

Deguen R. & Cardin P., Thermo-chemical convection in Earth's inner core. Geophysical Journal International, 187, 1101-1118, 2011.

Deguen R., Cardin P., Merkel S., & Lebensohn R. A. Texturing in Earth's inner core due to preferential growth in its equatorial belt. Physics of the Earth and Planetary Interiors, 188, 173-184, 2011.

Deguen R., Olson P. & Cardin P. Experiments on turbulent metal-silicate mixing in a magma ocean. Earth and Planetary Science Letters, 310, 303-313, 2011.

Alboussière, T., Deguen, R., & Melzani, M. Melting induced stratification above the Earth's inner core due to convective translation. Nature, 466 :744–747, 2010.

Venet L., Duffar T & Deguen R., Grain structure of the Earth's inner core. Comptes Rendus Geosciences, 341, 513-516, 2009.

Deguen R. & Cardin P., Tectonic history of the Earth's inner core preserved in its seismic structure. Nature Geoscience, 2, 419 - 422, 2009.

Deguen R., Alboussière T. & Brito D., On the presence and structure of a mush at the Earth's inner core boundary. Physics of the Earth and Planetary Interiors, 164, 36-49, 2007.

Deep Earth

Dominique JAULT, Henri-Claude NATAF, Philippe CARDIN, Renaud DEGUEN — 2019-10-10T09:25:50Z

One of the main objective of the group is to understand the dynamics and evolution of the deep interior of Earth and terrestrial planets. We use for this a combination of theoretical and numerical modelling, fluid dynamics experiments, and high pressure mineral physics experiments.

Topics currently under investigation include:
– the generation of magnetic field in planetary cores through dynamo effect
– accretion and core/mantle differentiation of terrestrial planets
– physical properties of the mantle and core of terrestrial planets (including exoplanets)
– convection in a crystallizing mantle and magma oceans
– Earth's inner core crystallisation and dynamics
– ...

Mineral Physics

Terrestrial planets are constituted of different layers, mainly a silicate mantle surrounding a metallic core. With increasing depth, pressure and temperature increase, modifying the physical properties of the materials, such as density, crystallographic structure, etc … These changes strongly affect the dynamic of the whole planet. To constrain the actual state of a planet, as well as its evolution from its early stage, it is mandatory to perform measurements on materials under planetary interiors conditions. Mineral Physics approach aim at using different experimental tools, such as Diamond Anvil Cell, Multi-Anvil press or Laser-driven Shock Compression, to unravel density, structure, phase diagram or transport properties of geomaterials under extreme conditions. The explored conditions will span from few GPa, for the Moon's interior, to several hundreds of GPa for large exoplanets.

Accretion and core/mantle differentiation of terrestrial planets

Current internship proposals

2019-04-16T12:35:34Z

– Topographic & buoyancy effects in turbulent boundary layers
supervisors: David Cébron & Nathanaël Schaeffer
contact: david.cebron univ-grenoble-alpes.fr
level: Master
duration: 4-6 months

– Modélisation 2D d'écoulements diphasiques en géodynamique interne: différentiation noyau/manteau, noyau interne, océans magmatiques
supervisors: R. Deguen, D. Cébron, G. Morard
contact: guillaume.morard univ-grenoble-alpes.fr
level: Master
duration: 4-6 months

– Dynamics in Earth's core from interannual to millenial time-scales
supervisors: Nicolas Gillet, Dominique Jault
contact: nicolas.gillet univ-grenoble-alpes.fr
level: Master
duration: 4-6 months

– construction d'un TP numérique d'analyse de données magnétiques satellitaires
supervisors: Nicolas Gillet, Mathieu Istas
contact: nicolas.gillet univ-grenoble-alpes.fr
level: Master
duration: 4-6 months

– Mélange d'un noyau liquide planétaire
supervisors: David Cébron (ISTerre)
contact: david.cebron univ-grenoble-alpes.fr
level: Stage de Master
duration: 3-6 months

– Turbulent boundary stress in the lunar core
supervisors: David Cébron (ISTerre)
contact: david.cebron univ-grenoble-alpes.fr
level: Stage de Master
duration: 3-6 months

– Liquid silicates under extreme conditions: implications for magma oceans differentiation
supervisors: Guillaume Morard (ISTerre) ; Jean-Alexis Hernandez (ESRF) ; Alessandra Ravasio (LULI, Ecole Polytechnique
contact: guillaume.morard univ-grenoble-alpes.fr
level: Stage de M2 Recherche
duration: 4-6 months (March-July 2022)