Elastic thickness and heat flux estimates for the uranian satellite Ariel

Abstract

10The surface of Ariel, an icy satellite orbiting Uranus, shows extensional tectonic features 11suggesting an episode of endogenic heating in the satellite's past. Using topography derived from 12 stereo-photoclinometry, we identified flexural uplift at a rift zone suggesting elastic thickness 13 values in the range 3.8-4.4 km. We estimate the temperature at the base of the lithosphere to be 14 in the range 99 to 146 K, depending on the strain rate assumed, with corresponding heat fluxes 15

Charon tectonics

“…This value is similar to that inferred at Arden Corona, Miranda ( Pappalardo et al, 1997 ). It is less than the T e values of 5–7 km for Ithaca Chasma on Tethys ( Giese et al, 2007 ) and 3.8–4.4 km from a rift zone on Ariel ( Peterson et al, 2015 ) (although some of our fits are in that range). The Charon value and those of the others are all larger than the 0.9 km for a rift flank on Ganymede ( Nimmo et al, 2002 ).…”

“…To investigate this issue further, we carried out flexural fits to a sub-set of rift-flank profiles ( Fig. 18 ) using the same approach that Peterson et al (2015) used for Ariel, and the same parameter values except for the gravity, 0.29 m s −2 . The mean elastic thickness T e we infer for Charon is 2.5 km.…”

“…While Serenity Chasma is about as deep as Ithaca Chasma, it is only half as wide ( Fig. 19 ), while Serenity is about twice as wide as the rifts at Miranda’s Arden corona ( Pappalardo et al, 1997 ) and graben on Ariel ( Peterson et al, 2015 ).…”

“…Each profile is labeled with the best-fit elastic thickness T e . Flexural fitting procedure and parameter values adopted are the same as in ( Peterson et al, 2015 ) except for the surface gravity.…”

Icy Satellites: Interior Structure, Dynamics, and Evolution

“…The leading explanation for this event is that the satellite was tidally heated when it was trapped in a "Laplace-like" resonance, prior to attaining its present-day orbital configuration (Showman & Malhotra1997). Similarly, the high ancient heat flux inferred at Tethys may have been due to passage through a 3:2 resonance with Dione (Chen & Nimmo 2008), and something similar may also have happened at Ariel (Peterson et al 2015). The Uranian satellites almost certainly experienced paleo-resonances, but there are no resonances at the present day.…”