Impact of tidal heating on the onset of convection in Enceladus’s ice shell

Běhounková, M.; Tobie, G.; Choblet, G.; Čadek, O.

doi:10.1016/j.icarus.2013.06.033

Cited by 28 publications

(27 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 and Supplementary Figs 11 and 14. The viscosity structures used in the present study are designed as simple analogues to viscosity fields obtained with full convection simulations in our previous studies 9, 31 . The viscosity above the ocean is approximately uniform, which mimics the temperature distribution within the ice shell due to the combined effect of tidal dissipation, convective motions, and possibly internal melting.…”

Section: Methodsmentioning

confidence: 99%

Timing of water plume eruptions on Enceladus explained by interior viscosity structure

Běhounková¹,

Tobie²,

Čadek³

et al. 2015

Nature Geosci

Self Cite

View full text Add to dashboard Cite

At the south pole of Saturn's icy moon Enceladus, eruptions of water vapour and ice emanate from warm tectonic ridges 1-4 . Observations in the infrared 5 and visible 6 spectra have shown an orbital modulation of the plume brightness, which suggests that the eruption activity is influenced by tidal forces. However, the observed activity seems to be delayed by several hours with respect to predictions based on simple tidal models 6,7 . Here we simulate the viscoelastic tidal response of Enceladus with a full three-dimensional numerical model 8,9 and show that the delay in eruption activity may be a natural consequence of the viscosity structure in the south-polar region and the size of the putative subsurface ocean. By systematically comparing simulations of variations in normal stress along faults with plume brightness data, we show that the observed activity is reproduced for two classes of interior models with contrasting thermal histories: a low-viscosity convective region above a polar sea extending about 45 • -60 • from the south pole at a depth below the surface as small as 30 km, or a convecting ice shell of 60-70 km in thickness above a global ocean. Our analysis further shows that the eruption activity is controlled by the average normal stress applied across the cracks, thus providing a constraint on the eruption mechanism.

show abstract

Section: Methodsmentioning

confidence: 99%

Timing of water plume eruptions on Enceladus explained by interior viscosity structure

Běhounková¹,

Tobie²,

Čadek³

et al. 2015

Nature Geosci

Self Cite

View full text Add to dashboard Cite

show abstract

“…We hypothesize that the initiation of viscous flow across the SPT was triggered by a transient heating event from below, which could have been induced by a rising plume, tidal heating, convection of warm ice, and/or coupling and feedbacks between the above processes (Nimmo and Pappalardo, 2006;Barr and McKinnon, 2007;Tobie et al, 2008;Běhounková et al, 2012Běhounková et al, , 2013Shoji et al, 2014) (Fig. 20E).…”

Section: Tectonic Model For the Evolution Of The South Polar Terrainmentioning

confidence: 97%

Gravitational spreading, bookshelf faulting, and tectonic evolution of the South Polar Terrain of Saturn’s moon Enceladus

Yin

Pappalardo

2015

Icarus

View full text Add to dashboard Cite

“…Such heating would result in localized lithospheric thinning and deformation [ Bland et al ., ; Spencer et al ., ; Barr and Preuss , ; Patthoff and Kattenhorn , ; Yin and Pappalardo , ]. The SPT may have formed in situ [ Běhounková et al ., , ], given that eccentricity‐induced tidal heating is elevated at the poles. Alternatively, subsurface concentration of warm ice and/or melting above a south polar sea could induce polar wander, moving a mass anomaly from lower latitudes to the satellite's pole [ Nimmo and Pappalardo , ; Collins and Goodman , ; Roberts and Nimmo , ].…”

Section: Introductionmentioning

confidence: 99%

Structural mapping of Enceladus and implications for formation of tectonized regions

Crow-Willard

Pappalardo

2015

J. Geophys. Res. Planets

View full text Add to dashboard Cite

Global structural mapping of high-resolution Cassini images of Enceladus reveals a richly varied surface. Most notable are three main regions of deformation each containing multiple structural units. In addition to the well known "South Polar Terrain" (SPT), there are two other large regions of deformation that we term "Leading Hemisphere Terrain" (LHT) and "Trailing Hemisphere Terrain" (THT). Each of these three terrains includes a circumferential belt that encloses one or more other structurally deformed units. Areal extents range from about 80,000 km 2 (SPT) to 195,000 km 2 (LHT) or 160 to 250 km equivalent circular radius.Based on relative crater densities, the THT is inferred to be older than the LHT; the geologically active SPT is the youngest. The overall similarities in shape and dimension of the three tectonized terrains suggest similar formational processes, plausibly related to broad loading of a thin elastic shell. A viable scenario is that each tectonized terrain formed above a large-scale region of warm upwelling ice, with subsequent downwarping triggered by cooling and/or subsurface melting. However, differences in morphological detail suggest that the specific evolution of each tectonized terrain has been different.

show abstract

Impact of tidal heating on the onset of convection in Enceladus’s ice shell

Cited by 28 publications

References 45 publications

Timing of water plume eruptions on Enceladus explained by interior viscosity structure

Timing of water plume eruptions on Enceladus explained by interior viscosity structure

Gravitational spreading, bookshelf faulting, and tectonic evolution of the South Polar Terrain of Saturn’s moon Enceladus

Structural mapping of Enceladus and implications for formation of tectonized regions

Contact Info

Product

Resources

About