Optional ZOOM LINK

Abstract: Ocean worlds such as Europa and Enceladus are prime exploration targets for NASA now and in the coming decades. Spectral observations from spacecraft and ground-based telescopes tell us that the composition of their icy shells is distinct from Earth’s sea ice, with dominant salts such as magnesium sulfate and sodium carbonate rather than sodium chloride. Because these icy worlds are physically inaccessible, scientists rely on modeling to interpret observations and understand the dynamics of both the surface and subsurface, however most models still use physical parameters for fresh water ice or Earth sea ice because experimental values for planetary ices do not yet exist.

My work aims to characterize the effects of planetary ice composition on mechanical properties to better inform models and interpret observational data. This is done by growing ices in the lab with compositions relevant to Europa, Enceladus, and Earth at varying salinities. Part 1 of the study looks at porosity-permeability relationships used in binary alloy solidification modeling to understand their influence on model results at scales of both Earth sea ice (meter-scale) and planetary ice shells (kilometer-scale). Part 2 describes experimental results in characterizing porosity and permeability within lab-grown planetary ices. Part 3 discusses completed and ongoing experiments to test flexure strength, compressive strength, and shear strength of planetary ices for rheologic behavior and failure. The results of this work are highly-anticipated by the planetary science community and represent a significant improvement in modeling and interpretive capabilities for geophysicists and astrobiologists.

Thesis Committee: Colin Meyer (chair), Jacob Buffo, Don Perovich, Marisa Palucis, Kate Craft (JHU/NASA APL)