Tidal dissipation in a viscoelastic planet

Open Access
Publisher Website
Google Scholar
Abstract
The rates of energy dissipation in tidally distorted Kelvin‐Voigt, Maxwell, and standard linear solid (SLS) viscoelastic moon models are calculated for a hypothetical past lunar orbit with semimajor axis 34.2 earth radii and obliquity = 49°. Viscosities of 1014 and 1018 Pa s for the Kelvin‐Voigt and Maxwell rheologies, respectively, are needed to match the dissipation rate calculated using the Q approach with a quality factor Q = 100. The SLS model requires a short time viscosity of 3×1017 Pa s to match the Q = 100 dissipation rate independent of the model's relaxation strength. Since Q = 100 is considered a representative value for the interiors of terrestrial planets, the derived viscosities should characterize planetary materials. Neither the Kelvin‐Voigt nor SLS models simulate the behavior of real planetary materials on long timescales. Therefore the significance of the viscosities inferred for these models is unclear. The Maxwell model behaves realistically on both long and short timescales. The inferred Maxwell viscosity, corresponding to a timescale of days, is several orders of magnitude smaller than the longer timescale (≥ 104 years) viscosity of the earth's mantle.

This publication has 18 references indexed in Scilit: