Exploring the Interiors of Icy Planetary Bodies via Geodynamical Modeling
thesisposted on 01.08.2019, 00:00 authored by Sean T O'Hara
I present the results of three studies that utilize numerical methods to explore the link between the internal geophysical state of icy solar system bodies and their exteriors. The first study explores the emplacement of the chaotic mountain block ranges found along the eastern rim of Pluto’s Sputnik Planitia basin, and finds that the mountains could have been emplaced by basal sliding lubricated by solid nitrogen on a geologically short timescale. The second study is focused on the enigmatic “cantaloupe terrain” of Neptune’s moon Triton. I test the compositional diapir hypothesis described by Schenk and Jackson (1993) using modern numerical simulation techniques. I find that a compositionally layered crust would behave in a more complex manner than the geometrically and rheologically simple diapir model. The third study develops a method for understanding the interior structure of a planetary body from observations of its spatially variable gravitational field. I present a forward-modeling C++ code that utilizes genetic algorithms and a simplified potential field generation model to bypass the assumptions required for the traditional inverse modeling approach.