Figure 1. Views of plate-like terrain on Mars, and pack-ice on Earth. From the paper linked below.
a, Part of an HRSC image of Mars from orbit 32, with a resolution of 13.7 m per pixel, centred at 5.5° north latitude and 150.4° east longitude, showing plate-like deposits with signs of break-up, rotation and lateral movement to the west-southwest in the lower part of the image. Scale bar is 25 km. b, Synthetic Aperture Radar image of pack-ice in the Weddell Sea, Antarctica. Scale bar is 25 km. (ESA image, processed by H. Rott.) c, Enlarged view of raft 7 × 12 km showing 8° rotation anticlockwise, causing the clear lane downstream of island ‘I’ to be curved. Leads ‘L’ downstream of the crater and small island at lower right are almost straight, indicating unidirectional drift slightly north of westward. Note pressure ridges ‘P’ upstream of islands. Arrows show relative motion vectors of individual plates. Scale bar is 10 km.
In Murray et al. (2005) in the journal Nature with the significant title
"Evidence from the Mars Express High Resolution Stereo Camera for a frozen sea close to Mars'equator" images from the above-named camera are presented from which is inferred the existence of a frozen body of water, with surface pack-ice, around 5$^0$ north latitude and 150$^0$ east longitude in the Cerberus Palus region.
The frozen lake should measure about 800 x 900 km in lateral extent with a depth of up to 45 meters !
Have there been observations by any radar instrument or neutron detector that can confirm or invalidate the existence of the putative frozen lake in the Cerberus Palus region ?
And is there further evidence from high resolution cameras for the existence of ice deposits within this region since the publication of the article in 2005 ?
Figure from "Evidence from the Mars Express High Resolution Stereo Camera for a frozen sea close to the Mars' equator"
Evidence of ice surface lowering and draping of plain-like features over partly submerged craters.
Update :
From this ESA article:
Two observations suggest that the ice is still there: first, the submerged craters are too shallow, indicating most of the ice is still in the craters; and second, the surface is too horizontal - if the ice had been lost, there would be a greater height variation.