Thermophysical assessment on the feasibility of basal melting in the
south polar region of Mars
Bright basal reflectors in radargram from the Mars Advanced Radar for
Subsurface and Ionosphere Sounding (MARSIS) of the Martian south polar
layered deposits (SPLD) have been interpreted to be evidence of
subglacial lakes. However, this interpretation is difficult to reconcile
with the low Martian geothermal heat flow and the frigid surface
temperature at the south pole. We conduct a comprehensive thermophysical
evolution modeling of the SPLD and show that subglacial lakes may only
form under exceptional circumstances. Subglacial lakes may form if the
SPLD contains more than 60 % dust volumetrically or extremely porous
ice (>30 %), which is unlikely. A thick (>100
m) layer of dirty ice (>90% dust) at the base of the SPLD
may also enable basal melting, resembling a sludge instead of a lake.
Other scenarios enabling subglacial lakes in the SPLD are equally
unlikely, such as recent magmatic intrusions at shallow depths.