MATLAB source code to reproduce the results in: Rhoden, A.R., Rudolph, M.L., and Manga, M. (in review). The challenges of driving Charon’s cryovolcanism from a freezing ocean. Icarus. The code is based on: Rudolph, M.L., Manga, M., Walker, M., and Rhoden, A.R. (2022). Cooling crusts create concomittant cryovolcanic conduits. Geophysical Research Letters 49(5), e2021GL094421 The equations solved by the code are derived in the Supplemental Material for Rudolph et al., (2022). They describe the temperature and stress evolution of icy moons, with application to Europa and Enceladus. Requirements: - MATLAB 2020a or later due to the use of tiled layouts. - Fabio Crameri's scientific colormaps Description of files: - The main driver program is ```thickening_ice_shell_with_ammonia.m```. - Helper subroutines are located in the subdirectory ```core/``` - Files in the ```benchmarks/``` subdirectory can be used to reproduce the results in Nimmo (2004).