A unified nomenclature for tectonic structures on the surface of Enceladus

True polar wander of Enceladus from topographic data

“…Both convective regimes show, in general, good agreement with the overall arrangement of geological provinces discussed above; for example, the resurfaced leading and trailing hemispheres, which used to be at the paleo-poles (Fig.2b), are superficially similar to the SPT, but differ significantly in the overall placement and nature of their terrain sub-units (Crow-Willard & Pappalardo, 2015). However, among the geological features in the provinces are structures located in the geologically named "Transitional" terrain (Crow-Willard & Pappalardo, 2015) (at S1-S2, and ) such as peculiar ropy folds, called funiscular plains, materials that are otherwise found exclusively in the SPT region (Crow-Willard & Pappalardo, 2015;Spencer et al 2009;Helfenstein et al 2010;Nahm & Kattenhorn, 2015), hinting at past possible activity in Enceladus' paleo-poles. These are discussed in greater detail below.…”

Surface deposition of the Enceladus plume and the zenith angle of emissions

“…Multiple particle sizes from 0.6 − 15 µm are simulated for each source location, and data are generated on the impact flux in particles/sec/m 2 and mass deposition in mm/year across the surface of Enceladus. Initial simulated maps of surface deposition from the Enceladus plume published in Kempf et al (2010) have received interest from the larger research community (for example, Di Sisto and Zanardi, 2016;Nahm and Kattenhorn, 2015;Scipioni et al, 2017) and, here, we provide a more complete set of maps and data with respect to source location and particle size. Using the newly generated surface data for a curtain-style plume (Spitale et al, 2015) and the ∼ 100 discrete jets proposed in Porco et al (2014), we provide new insight into the zenith angle of plume emissions, that is, the "tilt" of the jets.…”

The impact of a pressurized regional sea or global ocean on stresses on Enceladus

“…The SCT, which lies along the edge of the SPT, especially in the eastern hemisphere, constitutes a mountain belt at least a kilometer high [ Schenk and McKinnon , ] with curved, parallel ridges, and grooves originally interpreted as compressional features [ Gioia et al ., ; Spencer et al ., ]. A newer analysis puts this interpretation in question, though, pointing out the presence of grabens near the summit of the range [ Nahm and Kattenhorn , ]. However, as graben can develop at the summit of compressional ranges on Earth due to differences in gravitational potential energy [e.g., Molnar and Lyon‐Caen , ], this observation does not, on its own, contradict a compressional origin for the SCT.…”

“…The satellite of Saturn, Enceladus, displays a surprising amount of tectonic activity in spite of its relatively small size (Figure ) [e.g., Crow‐Willard and Pappalardo , ; Nahm and Kattenhorn , ]. Tectonic activity and geophysical and geochemical evidence indicate that a global or regional ocean is likely present underneath the ice shell [e.g., Nimmo and Pappalardo , ], with important implications for the astrobiological potential of the satellite [ Hsu et al ., ; Glein et al ., ].…”

“…A high heat flow at the SPT is inferred from direct measurements and modeling of tectonic length scales [Spencer et al, 2006;Bland et al, 2012Bland et al, , 2015. The SPT as a whole is surrounded by a deformation belt, the Southern Curvilinear Terrain (SCT), originally interpreted to be a compressional feature [e.g., Porco et al, 2006], although extension and shearing are also involved in generating this terrain [Spencer et al, 2009;Nahm and Kattenhorn, 2015]. In an icy satellite with a radius of 252 km and an orbital eccentricity of only 0.0047 it is surprising to find ongoing geologic activity.…”