Séminaire ISTerre

On the effects of topography in rapidly rotating fluids: Experiments on the spin-up of a fluid in a straight cylinder with bottom topography

jeudi 28 mars 2024 - 11h00
Jérôme Noir - ETH Zürich, Institut für Geophysik
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Deep seated planetary fluid envelops, such as metallic cores or subsurface oceans, play a fundamental role in the orbital evolution of the celestial objects via transfer of angular momentum and energy dissipation, and the generation of a magnetic field or mixing of chemical species. From a dynamical stand point these buried fluid envelops are rapidly rotating, stably, neutrally or unstably stratified regions enclosed in a solid shell. The interest in their dynamics dates back from the end of the 19th century when scientists proposed to probe internal structures of planets and moons by monitoring their rotation, initiating research on how the presence of fluid layers can reflect in their rotational dynamics. They first considered the hydrodynamics of rapidly rotating spherical shells, then spheroidal shells and more recently tri-axial ellipsoids. Meanwhile, we have geodynamical arguments and seismic observations suggesting that the Earth's Core-Mantle boundary (CMB) may not be a smooth surface but exhibit topographic features of various height and wavelengths, which have not been considered so far.
In this presentation, I will briefly introduce the geophysical context and explain why the abundant results on the topic in oceanography and atmospheric sciences may not apply to those deep fluid layers. I will then present the results from a dedicated experimental study of the Spinup of a rapidly rotating fluid in a straight cylinder with chessboard-like topography at the bottom as a proxy to address topography driven energy dissipation. I will show the particular role played by inertial waves to radiate the energy away from the topography, and shape the internal flows. I will conclude by presenting ongoing and futur theoretical, numerical and experimental investigations to gain further insights.

Equipe organisatrice : Géodynamo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

Informations de visio :

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“Minimalist seismology”: studying earthquakes with sparse instrumentation

jeudi 17 septembre 2026 - 11h00

Mathieu Causse - ISTerre

Equipe organisatrice : Organisation labo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Stable‑to‑dynamic expansion of fault slipping area through fluid injection observed in laboratory experiments using a sub‑meter scale specimen

vendredi 18 septembre 2026 - 14h00

Takatoshi Ito  - Université de Tohoku, Japan

Equipe organisatrice : Mécanique des failles

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Tectonics, Mantle Dynamics and Coupled Lithosphere-Mantle-Core Evolution of Earth and Other Rocky Worlds

jeudi 24 septembre 2026 - 11h00

Paul Tackley - ETH Zurich

Equipe organisatrice : Grands Séminaires ISTerre

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Tectonics, Mantle Dynamics and Coupled Lithosphere-Mantle-Core Evolution of Earth and Other Rocky Worlds

jeudi 24 septembre 2026 - 11h00

Paul Tackley - ETH Zurich

Equipe organisatrice : Grands Séminaires ISTerre

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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Apport des expériences analogiques pour la modélisation et le suivi en temps réel de la propagation du magma en profondeur : Exemple du Rift Est Africain

jeudi 1er octobre 2026 - 11h00

Virginie Pinel - ISTerre

Equipe organisatrice : Organisation labo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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A t-on encore besoin de plaques pour expliquer la tectonique de la vallée du Rhône et des Alpes Occidentales ?

vendredi 2 octobre 2026 - 11h00

philippe VERNANT - Geosciences Montpellier

Equipe organisatrice : Tectonique active et sismicité

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 2 octobre 2026 - 14h00

Hugo Boulze - 

Equipe organisatrice : Cycle sismique et déformations transitoires

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 9 octobre 2026 - 11h00

Eric Beaucé - ISTerre

Equipe organisatrice : Cycle sismique et déformations transitoires

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

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TBA

vendredi 20 novembre 2026 - 11h00

Farzaneh Mohammadi - ENS Paris

Equipe organisatrice : Cycle sismique et déformations transitoires

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

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