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Accueil du site > Séminaires > Séminaires 2022 > MSC Seminar. May 9th 2022 at 11:30. Nicolas Taberlet (ENS Lyon) : " Sublimation-driven morphogenesis of Zen stones on ice surfaces & onset of glacier tables".

MSC Seminar. May 9th 2022 at 11:30. Nicolas Taberlet (ENS Lyon) : " Sublimation-driven morphogenesis of Zen stones on ice surfaces & onset of glacier tables"

Sauf mention contraire, les séminaires et les soutenances se déroulent à 11h30 en salle 454A du bâtiment Condorcet.


There will be a live diffusion with Zoom.

Monday May 9th, 11h30

Contact Michael Berhanu to attend the visio-seminar

Sublimation-driven morphogenesis of Zen stones on ice surfaces & onset of glacier tables

Nicolas Taberlet

Laboratoire de Physique, Ecole Normale Supérieure de Lyon.

In this talk, the formation of Zen stones on frozen lakes and the shape of the resulting pedestal are elucidated. Zen stones are natural structures in which a stone, initially resting on an ice surface, ends up balanced atop a narrow ice pedestal. We provide a physical explanation for their formation, sometimes believed to be caused by the melting of the ice. Instead, we show that slow surface sublimation is indeed the physical mechanism responsible for the differential ablation. We reproduced the phenomenon in laboratory-scale experiments conducted in a lyophilizer and studied the dynamics of the morphogenesis. Numerical simulations, in which the local ablation rate of the surface depends solely on the visible portion of the sky, allow us to study the influence of the shape of the stone on the formation of the ice foot. Finally, we show that the far-infrared black-body irradiance of the stone itself leads to the formation of a depression surrounding the pedestal.

I will also briefly present our work on glacier tables, which consist of a rock supported by a slender column of ice and form naturally on glaciers. We investigated the onset of their formation at a smaller scale in a controlled environment. Depending on the size and thermal conductivity of a cap, it can either form of a table standing on an ice foot, or sink into the ice block. A one-dimension conduction model captures the transition between the two regimes and identifies a dimensionless number which controls the onset of glacier tables formation.


Contact : Équipe séminaires / Seminar team - Published on / Publié le 24 février


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