Simulating spatial variations of lithospheric folding in the south polar terrain of Enceladus

The South Polar Terrain (SPT) of Saturn's moon Enceladus is a young, heavily lineated region that has been shown to be actively venting cryovolcanically. A set of roughly evenly spaced, subparallel fissures, collectively known as the Tiger Stripes, cut across the SPT and is the source of the venting. Additionally, thermal observations demonstrated anomalously high heat flow coming out of the whole SPT in general, and the Tiger Stripes in particular; total heat power out of the region has been estimated to be similar to 5-18 GW, more than what can be supplied by equilibrium tidal heating and suggesting temporal variability in the thermal structure of the SPT. Between the Tiger Stripes are a series of closely spaced, short wavelength (1.1 km) linear features generally following the trend of the Tiger Stripes, which has been interpreted as folding of a surface layer undergoing compression. In addition, periodic ridges and troughs (5 km wavelength) found in the zone rimming the SPT have been interpreted recently as contractional features. Here, we simulate the formation of both types in order to constrain the thermal conditions required for their formation. Reproducing the shorter wavelength features necessitates high surface temperatures (185 K) and high heat flows (400 mW m(-2)), results consistent with past work. The long wavelength features need lower surface temperatures (130K) and heat flows (100 mW m(-2)), which demonstrates a spatial variability heat of lost from the center to the periphery of the SPT.

Automated summary

The South Polar Terrain (SPT) of Saturn's moon Enceladus is actively venting cryovolcanically, with the Tiger Stripes as the source. The SPT exhibits anomalously high heat flow, suggesting temporal variability in its thermal structure. The presence of linear features and periodic ridges and troughs further supports a complex thermal environment.