Effect of the tiger stripes on the deformation of Saturn's moon Enceladus

• Published in: Geophysical research letters Vol. 43; no. 14; pp. 7417 - 7423
• Main Authors: Souček, Ondřej, Hron, Jaroslav, Běhounková, Marie, Čadek, Ondřej
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 28-07-2016
• Subjects: Area; Astrophysics; Continuum mechanics; Deformation; Deformation effects; Emission; Enceladus; Estimates; Faults; Fractures; Friction resistance; Geological faults; Geophysics; Heat; Ice; Ice cover; Jets; Libration; Mechanics; Moon; Moons; numerical modeling; Plate tectonics; Polar environments; Polar regions; Saturn; Saturn satellites; South Pole; Strain; Stress concentration; Stresses; Subsurface water; tidal deformation; tiger stripes
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2016GL069415

Enceladus is a small icy moon of Saturn with active jets of water emanating from fractures around the south pole, informally called tiger stripes, which might be connected to a subsurface water ocean. The effect of these features on periodic tidal deformation of the moon has so far been neglected because of the difficulties associated with implementation of faults in continuum mechanics models. Here we estimate the maximum possible impact of the tiger stripes on tidal deformation and heat production within Enceladus's ice shell by representing them as narrow zones with negligible frictional and bulk resistance passing vertically through the whole ice shell. Assuming a uniform ice shell thickness of 25 km, consistent with the recent estimate of libration, we demonstrate that the faults can dramatically change the distribution of stress and strain in Enceladus's south polar region, leading to a significant increase of the heat production in this area.
Key Points
The presence of faults can significantly change the distribution of stress and strain in Enceladus's south polar region (SPR)
The deformation induced by faults leads to local increases of heat flux by a factor of 10 and a twofold increase in SPR on average
The effect of the faults on stress and strain is limited to SPR and is negligible at distances larger than 40 degrees from the south pole