Modeling Sublimation of Ice Exposed by Recent Impacts in the Martian

Introduction: High latitude ground ice on Mars was inferred in the shallow subsurface by hydrogen measurements using Mars Odyssey’s Gamma Ray Spectrometer (GRS) [1]. However, at mid to low latitudes, GRS found only small quantities of hydrogen, consistent with hydrated minerals. Recent observations have shown new small craters [2], and some in the mid-latitudes have exposed water ice at a depth of a few tens of centimeters [3] (Fig. 1). Such ice is unstable in the present climate. We use thermal modeling to examine the evolution of the observed ice and to calculate the ice loss due to sublimation at each site. This provides insight into the significance of changes observed at the impact sites in HiRISE image sequences. Five such sites have been discovered to date; for this abstract, we focus on the first site observed.