Abstract DGP2026-133

Heat loss due to melt extraction – the so-called heat-piping mechanism – can be an important contributor to the energy budget of terrestrial planets, influencing the long-term cooling of their interior [1]. Terrestrial planets are characterized by long periods of widespread volcanism, especially during the early stages of their evolution. Buoyant partial melt generated in the convective mantle migrates upward to reach the surface or intrudes at depth, where it solidifies to form the bulk of the secondary crust. In addition, newly extracted or intruded melt can displace existing crust, resulting in a net downward advection of cold material, contributing to the cooling of the interior [1,2].

The heat-piping mechanism can be accurately simulated with 2-D and 3-D dynamic simulations by locally quantifying the production of buoyant partial melt. However, these simulations are computationally expensive, which limits the systematic exploration of the vast parameter space of planetary interior models. To investigate the influence of the heat-piping mechanism more systematically, 1-D “parametrized” thermal evolution models provide a computationally efficient framework for exploring a much wider range of parameters. Yet, their treatment of heat piping has never been validated against high-fidelity 2-D and 3-D simulations.

The objective of this work is to develop and calibrate a parameterization of the heat-piping mechanism within a 1-D model of parameterized convection and interior evolution implemented in the code TEMPURA [3]. We systematically compare model predictions obtained with TEMPURA against the outcomes of existing 2-D simulations of the interior evolution of Mercury, Mars, Venus and the Moon carried out with the DLR mantle convection code GAIA [4], in order to evaluate how well the reduced 1-D formulation reproduces the first-order thermal effects of melt extraction.

For the four bodies, we compare the evolution of mantle and CMB temperatures, stagnant-lid thickness, melt production rate, and both convective and melt-related heat fluxes, considering cases in which melt is either extracted to the surface or retained within the mantle. Preliminary results highlight a very good agreement between the 1-D and 2-D models for a small planet with a thin mantle, such as Mercury, where convection is sluggish and melt production limited throughout much of the evolution. The comparison becomes more challenging for larger and hotter planets such as Venus, whose thicker mantle sustains more vigorous and long-lived melting, potentially driving
rapid crustal growth and recycling.

References
[1] Moore, W. B., & Webb, A. A. G. (2013). Heat-pipe Earth. Nature, 501(7468), 501–505.
[2] Peterson, G. A., Johnson, C. L., & Jellinek, A. M. (2021). Thermal evolution of Mercury with a volcanic heat-pipe flux: Reconciling early volcanism, tectonism, and magnetism. Sci. Adv., 7(40).
[3] Baumeister, P., Tosi, N., Brachmann, C., Grenfell, J. L., & Noack, L. (2023). Redox state and interior structure control on the long-term habitability of stagnant-lid planets. A&A, 675, A122.
[4] Herrera C., Plesa A.-C., Maia J., Breuer D. The role of magmatic styles in planetary thermal evolution models. Submitted.