Fischer, RebeccaDong, Junjie2023-06-0220232023-05-122023-05Dong, Junjie. 2023. Water and Phase Transitions in Rocky Planetary Interiors. Doctoral dissertation, Harvard University Graduate School of Arts and Sciences.30492272https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37375828This dissertation explores two fundamental aspects of rocky planetary interiors: water and phase transitions. The first two chapters investigate the deep water cycles in Earth and Mars. The research provides an estimate of the bulk water storage capacity of their mantles as a function of mantle potential temperature using thermodynamic modeling, and examines its implications for the hydrosphere of early Earth through isostatic modeling. In the third chapter, a machine learning framework is introduced for determining high-pressure phase diagrams, with a specific focus on the post-spinel transition in Mg2SiO4. The resulting nonlinear Clapeyron slope of the post-spinel transition is then used to estimate its lateral variation at the base of the Earth’s transition zone.application/pdfenGeophysicsMineralogyPaleontologyThesis or Dissertation2023-06-020000-0003-1114-9348