Ripple migration and dune activity on Mars: Evidence for dynamic wind processes



[1] In this report we show evidence of widespread ripple migration over the stoss side of dark barchan dunes in Nili Patera on Mars. The measured average migration of ∼1.7 meters in less than 4 terrestrial months clearly indicates that active sand saltation is occurring in the study area. In addition, we document widespread changes in the dune base-ground surface contact and in the slip face structures, showing that not only the ripples, but the whole dunes are actually migrating in the present-day atmospheric setting. These results provide unequivocal evidence of recent aeolian activity and suggest that other dunes and ripples on Mars may also be active.