SHARAD detection and characterization of subsurface water ice deposits in Utopia Planitia, Mars

Morphological analyses of Utopia Planitia, Mars, have led to the hypothesis that the region contains a substantial amount of near-surface ice. This paper tests this hypothesis using ground-penetrating radar techniques. We have identified an expansive radar reflective region spanning approximately 375,000 km2 in SHAllow RADar (SHARAD) data over western Utopia Planitia. The SHARAD reflective regions coincides with high densities of scalloped depressions and polygonal terrain. The reflectors are associated with layered mesas ∼80–170 m thick. We find a value of 2.8 ± 0.8 for the dielectric constant of the material overlying the reflectors. This work finds that the dielectric constant is consistent with a mixture of ice, air, and dust, containing a water ice volume up to 14,300 km3 in this unit.