Figure 4
Detailed analysis of the SHPD's lobate margin pinpointed in Fig. 3b, as captured in HiRISE image ESP_071490_1805 with approximately 50 pixels/degree. Key geological features are highlighted: blue arrows direct attention to scour marks trending northwest and northeast, depicted by closely spaced grooves and ridges (panels b–d). The grooves and ridges likely indicate the erosional effects from crosswinds. Within some of these ridges are boulder piles, suggestive of localized aeolian deflation, as highlighted by white arrows in panel (d) and (e). The yellow arrows in panels (b) and (c) emphasize the truncation of various craters by the grooves. Red arrows in panels (b–e) denote the widespread presence of degraded craters with diameters ≤ ~ 100 m, with some further eroded into somewhat irregular and apparently flat-rimmed or rimless depressions at certain locations, as demonstrated within the zone bordered by the dashed white line in panel (e). Note that although the arrowheads in panel (e) end at pits, their primary role is to emphasize the lineated spatial trends they indicate. Image credit: NASA/JPL/University of Arizona Usage policy.
