An Approach To Modelling Ice Deposition Across The Solar System

Abstract

This dissertation presents an approach to examining the exotic ices behaviour, and reconstructing non-terrestrial the glacial history (under planetary conditions other than those of Earth), including those of stratified CO2 icesheets near Mars’ south pole, through high-resolution computer simulations. Modelling ices on other planets (e.g., on Mars) is vastly different from those on Earth; hence the approach will be different for paleo-non-terrestrial glacial modelling. For this, I have augmented JPL’s Ice-sheet and Sea-level System Model (ISSM) to support multi-unit ice masses, temperature-dependent material properties (beyond the already temperature-dependent rheology), and Martian environmental boundary conditions. This new codebase, the Multi-unit Ice Deposits Analysis and Simulation (MIDAS) framework, enables the study of complex, stratified ice systems with realistic thermo-mechanical coupling under planetary conditions. Here, I also provide two practical case studies for the application of MIDAS on Mars: the first examines the geomorphic evolution of Mt. Sharp (Aeolis Mons) in Gale Crater, where observations by the Mars Science Laboratory Curiosity rover reveal bedrock features resembling terrestrial glacial landforms. Using MIDAS, three-dimensional flow of cold-based, debris-free glaciers were modelled to examine the hypothesis that former glacial activity could have contributed to the nearby erosional features. The purpose of modelling was only to examine the potential direction of the ice flow. The modelling results show that ice accumulation and flow could have reached to shape the key landforms observed today. The second case study focuses on the Massive CO₂ Ice Deposits (MCID) beneath the Martian South Polar Layered Deposits, where MIDAS was used to simulate the formation and thermo-mechanical evolution of the MCID’s stratified CO₂–H₂O ice units over 510,000 years. The modelled results demonstrate that the inclusion of viscous and thermally conductive water-ice bounding layers could reduce internal temperatures and strain rates, and stabilize the overall set of CO2 ice units.