Modeling cryogenic mud volcanism on Pluto

by Ahrens, C. J.

Subsurface ice cryofluids and ice interactions with ammonia for cryovolcanic materials give the potential ingredients for the formation of mud volcanoes on Pluto. In order to constrain the possible morphology from images acquired by the New Horizons spacecraft, we have modeled the formation of mud volcanoes, isostatic layers of ice overlain by denser material, from a series of possible solid-liquid "mud" compositions (methane and ammonia), as well as accounting for the full range of eruption variables (e.g., mud viscosity, conduit diameter, and eruption duration). We categorize them into nine specific scenarios based on the composition of the top ice layer and mud composition. From these scenarios, the maximum height of the potential mud volcano can be calculated. We find that ammonia mud sources produce smaller edifice heights and wider flow profiles compared to methane dominant mud cryovolcanoes. Assuming certain preliminary parameters, we also propose the evolution and development of the edifice of Wright Mons in as little as 3.8 million years given a 10 wt% ammonia subsurface mud composition. If characterized on Pluto's surface, mud volcanoes would provide an interesting insight on the subsurface dynamics of solids and cryofluids on Pluto.

Journal of Volcanology and Geothermal Research