Airy isostasy on icy moons: Assessment of different approaches
Abstract
We have examined the accuracy of different approaches to modeling Airy isostasy by comparing their results with those obtained from the numerical solution of the equations for viscous flow in the shell of an icy moon with a subsurface ocean. We find that the traditional approach to Airy isostasy, based on simple application of Archimedes' principle, provides a satisfactory estimate of crustal thickness variations at low harmonic degrees. The minimum stress approach, originally proposed by Dahlen (1981) and recently applied to icy moons by Beuthe et al. (2016), leads to results that closely (to within numerical accuracy) match those obtained from the steady-state solution of flow equations. The least satisfactory results are obtained using the equal pressure approach recently proposed by Hemingway and Matsuyama (2017) as an alternative to the traditional approach. The equal pressure approach significantly overestimates the amplitude of the surface topography for all harmonic degrees, suggesting that the deviatoric stress cannot be neglected in the analysis of topographic data.
- Publication:
-
EPSC-DPS Joint Meeting 2019
- Pub Date:
- September 2019
- Bibcode:
- 2019EPSC...13..829C