Kenny Vilella

Abstract Observations of icy satellites have revealed widespread marks of cryovolcanism. Because aqueous cryomagmas are negatively buoyant, two processes are required to explain these observations: one mechanism to generate melt close enough to the surface and another one to transport this melt to the surface. Here, we investigate the generation of melting in a systematic way, using a set of 85 numerical simulations where we vary the viscosity contrast, Rayleigh number, and tidal heating rate. A

Motions in the solid mantle of silicate planets are predominantly driven by internal heat sources and occur in laminar regimes that have not been systematically investigated. Using high-resolution numerical simulations conducted in three dimensions for a large range of Rayleigh–Roberts numbers ( $5\times 10^{3}\leqslant Ra_{H}\leqslant 10^{9}$ ), we have determined the characteristics of flow in internally heated fluid layers with both rigid and free slip boundaries. Superficial planforms evolve

Thermal evolution of terrestrial planets is controlled by heat transfer through their silicate mantles. A suitable framework for modelling this heat transport is a system including bottom heating (from the core) and internal heating, for example, generated by secular cooling or by the decay of radioactive isotopes. The mechanism of heat transfer depends on the physical properties of the system. In systems where convection is able to operate, two different regimes are possible depending on the re

Abstract High‐resolution pictures of Pluto's surface obtained by the New Horizons spacecraft revealed, among other surface features, a large nitrogen ice glacier informally named Sputnik Planitia. The surface of this glacier is separated into a network of polygonal cells with a wavelength of ∼20–40 km. This network is similar to the convective patterns obtained under certain conditions by laboratory experiments, suggesting that it is the surface expression of thermal convection. Here we investig

Abstract Experimental and theoretical studies have shown that the iron spin transition alters the properties of lower mantle minerals. This may have important implications for mantle dynamics. In particular, the vigor of convection is enhanced, which in turn may impact the stability of large primordial reservoirs at the base of the lower mantle. Here we performed numerical experiments of thermochemical convection in 2‐D annulus geometry including the change of density induced by iron spin transi

Abstract Earth's continental crust is characterized by a strong enrichment in long‐lived radioactive isotopes. Recent estimates suggest that the continental crust contributes to 33% of the heat released at the surface of the Earth, while occupying less than 1% of the mantle. This distinctive feature has profound implications for the underlying mantle by impacting its thermal structure and heat transfer. However, the effects of a continental crust enriched in heat‐producing elements on the underl

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La convection thermique a un role fondamental sur l'evolution thermique d'une planete tellurique, telle que la Terre. La complexite de ce phenomene est ici etudiee avec des simulations numeriques et une modelisation theorique. La premiere partie de cette these presente les simulations numeriques d'un systeme convectif de reference, sous l'approximation de Boussinesq, consistant en une couche horizontale de fluide possedant une condition de flux de chaleur nul a la base et de temperature constant

Summary Melting in planetary mantles plays a key role in their thermo-chemical evolution. Assessing the amount and location of melting generally requires the 3D temperature fields of the system, such that 3D numerical simulations are in principle necessary prohibiting us from exploring wide ranges of conditions. To overcome this issue, we propose a new 1D analytical framework estimating at first order the amount and depths of melting for a simplified convective system. To do so, we develop an ap