PISCOPO ALESSANDRA

Eberswalde crater on Mars preserves a stratigraphic record of three aeolian bedform generations (G1–G3),
totaling 1,903 mapped features across 15 study areas, that trace changing wind regimes through the Late
Amazonian period. Bedforms were assigned to generations using morphometric parameters (height, crest
length, etc) and morphogenetic criteria, cross-checked against stratigraphic superposition. Vector-mean wind
directions rotate from SE/S (G1, ≈126°) through a bimodal SW/E phase (G2, ≈141°) to a dominant easterly
regime (G3, ≈101°), independently corroborated by 43 E-oriented bedforms in the F-basin, attributed to G1.
Crater size-frequency dating yields a Late Amazonian resurfacing age of 342 ± 15 Ma, linked to G1 activity.
This succession is interpreted within the ~120-kyr obliquity cycle of Laskar et al. (2004): higher obliquity
destabilizes polar CO2, lowering the saltation threshold. Comparison with Mars Climate Database winds shows
no present-day analogue for the G3 signal. These results and other works are in progress.

Figure 1. Comparative rose diagrams of vector-mean wind (sediment-transport) directions for bedform generations G1, G2 and G3
at Eberswalde crater, showing the progressive anticlockwise rotation from SE/S to E.

Figure 2. Conceptual schematic linking Mars' ~120-kyr obliquity cycle (Laskar et al., 2004) to atmospheric pressure and the aeolian
saltation threshold, framing the G1–G3 wind-regime succession within Late Amazonian climate variability.