Table 12.

Shallow Subsurface Structure EPM

Regime	SS01(07)	SS02(08)	SS03(09)	SS04(10)	SS05(11)	SS06(12)
Surface Roughness	Ridged Plains	Chaotic Terrain	Chaotic Terrain	Ridged Plains	Ridged Plains	Chaotic Terrain
Near-Surface Density	Non-Porous
Near-Surface Thickness	Thin
Near-Surface Composition	Clean Ice
Off-Nadir Surface Feature	Ribbons & Curbs
Deep Regolith	Absent	Present	Absent	Absent	Absent	Absent
Surface Temperature	Polar & Equatorial
Ice Shell Composition	Marine	Pure	Pure	Marine	Pure	Marine
Ice Shell Thickness	Thin
Subsurface Water Interface	Sharp	Sharp	Sharp	Mush	Sharp	Sharp
Basal Temperature	Melting	Melting	Melting	Eutectic	Melting	Melting
(Salt Layer Thickness)	1 m
(Salt Layer Depth)	1/2 Ice Shell Thickness