An Algorithm for Thermodynamic Parameter Optimization: Application to the Martian Mantle

Abstract

AbstractThe compilation of thermodynamic models for geophysical applications is such a tedious and complex process that it is generally impractical for researchers to refit parameters in existing models in light of new constraints. To mitigate this difficulty, we develop a Bayesian algorithm that permits the modification of a thermodynamic model to account for additional observational constraints. This algorithm can be applied to any thermodynamic dataset and can utilize a wide variety of experimental constraints. To demonstrate the applicability of the algorithm it is used to revise the Stixrude and Lithgow‐Bertelloni (2011, https://doi.org/10.1111/j.1365‐246x.2010.04890.x), whole‐mantle terrestrial thermodynamic model, using phase equilibrium constraints provided by Bertka and Fei (1997, https://doi.org/10.1029/96jb03270), for the more iron‐rich compositions that are thought to be relevant to the Martian mantle. The revised thermodynamic model provides a more reliable prediction of phase equilibria in the Martian mantle. Seismic properties are calculated in an internally self‐consistent manner along hot and cold areotherms to constrain the upper and lower bounds of these properties for different bulk silicate Mars compositional models.