Latest Publication: Dune Migration on Mars

Cardinale, M., Silvestro, S., Vaz, D.A., Michaels, T., Bourke, M.C., Komatsu, G., Marinangeli, L., (2016). Present-day aeolian activity in Herschel Crater, Mars. Icarus, 265, 139-148.

This paper presents evidence for ripple and dune migration in Herschel Crater on Mars.

cardinale

Figure 3 from Cardinale et al (2016). Fig. 3. (a) The pattern of the ripples superposing the dune slopes is complex due to the diverse wind flow over the dunes. (b) An inset of dune horn, where along its flanks, the ripple crests present a continuous pattern. (c) Ripple length-weighted distribution in Herschel Crater (the relative frequency for each 5° bin is shown). The ripple population (the mapped area corresponds to the yellow window shown in Fig. 2) denotes a bimodal trend with two prevailing directions centered at ∼45° and ∼135°.

We estimate an average dune migration of 0.8 m and a minimum ripple migration of 1.1 m in a time span of 3.7 Earth-years. These dunes and ripples are mainly shaped by prevailing winds coming from the north, however we also report the presence of secondary winds which elongate the barchans’ horns. Such a complex wind scenario is likely caused by the influence of winds blowing off the western crater rim as suggested by the Mars Regional Atmospheric Modeling System (MRAMS), an atmospheric mesoscale model. A multi-directional wind regime at the local scale is also supported by the observed bimodal distribution of the ripple trends. For the first time, a survey integrating the assessment of dune and ripple migration is presented, showing how dune topography can influence the migration patterns of ripples and how underlying topography appears to control the rates of dune migration.

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