Terrestrial constraints on the distribution of brine in Europa’s ice shell ...

• Main Authors: Wolfenbarger, Natalie Soheila, 0000-0001-7990-3891
• Format: Thesis
• Language: English
• Published: The University of Texas at Austin 2022
• Subjects: Europa; Habitability; Ice shell; Ice; Brine; Salt; Sea ice; Enceladus; FREZCHEM; PHREEQC; Biosignature; ice core; Ice Shelves
• Online Access: https://dx.doi.org/10.26153/tsw/46193; https://repositories.lib.utexas.edu/handle/2152/119315

Jupiter’s ice-covered moon Europa is considered a prime target in the search for habitable worlds within our Solar System. Freezing at the ice-ocean interface (accretion) entrains material from the ocean, including salts and potential biosignatures. In this work, we first examine how accreted ice on Earth can be used to estimate the bulk composition of Europa’s ice shell through a review of published ice core data, sampling low temperature gradient environments. We find that ice forming beneath ice shelves can serve as a valid analog for ice accreting beneath the ice shells of Europa and Enceladus and that the mechanism of ice accretion (frazil vs. congelation) will serve as the primary factor governing the amount of salt entrained in the ice shell from the ocean. We then introduce a framework to model the brine, salt, and ice volume fraction for a given composition as a function of bulk salinity and temperature by translating the output of the aqueous geochemistry software to polynomial functions of ...