Morphology, Development, and Sediment Dynamics of Elongating Linear Dunes on Mars

Abstract

Linear dunes occur on planetary surfaces, including Earth, Mars, and Titan, yet their dynamics are poorly understood. Recent studies of terrestrial linear dunes suggest they migrate by elongation only in supply-limited environments. Here, we investigate elongating linear dunes in the Hellespontus Montes region of Mars which are morphologically similar to terrestrial systems. Multitemporal, high-resolution orbital images show these linear dunes migrate by elongation only and that the fixed sediment source of the dunes probably restricts any lateral migration. Some linear dunes maintain their along-length volume and elongate at rates comparable to adjacent barchans, whereas those which decrease in volume show no elongation, suggesting they are near steady state, matching morphometric predictions. Limited sediment supply may restrict Martian linear dunes to several kilometers, significantly shorter than many terrestrial linear dunes. Our results demonstrate the close similarities in dune dynamics across the two planetary surfaces. Plain Language Summary Linear dunes are elongated sand ridges found on Earth, Mars, and Titan and form in areas with at least two wind directions. The way in which linear dunes move is poorly understood, in particular whether they migrate parallel or perpendicular to their ridge crests. Recent investigations have suggested that linear dunes on Earth migrate parallel to their ridge crests in areas with a fixed source of limited sand. The surface of Mars is a natural laboratory for investigating linear dunes. We use time series, high-resolution orbital images to investigate the migration of Martian linear dunes. Like those on Earth, the Martian linear dunes also originate from a fixed sand source and grow parallel to their crests only. Furthermore, we also show that the linear dunes no longer grow as they approach a steady state. Our results demonstrate strong similarities in the behavior of dunes on Mars and Earth.

Ancient Martian Aeolian Sand Dune Deposits Recorded in the Stratigraphy of Valles Marineris and Implications for Past Climates

“…At a broad scale modern examples show similar trends in morphology and overall field shape. For example, relatively symmetric parallel rows of barchans at the upwind edge of fields may develop from a linear sand source under a largely unidirectional wind regime (Figure 8) (Davis et al, 2020; Ewing et al, 2010). In these cases, more complicated dune morphologies occur in downwind areas likely due to a combination of factors (e.g., dune‐dune interactions, variable wind directions, or topography).…”

A Rock Record of Complex Aeolian Bedforms in a Hesperian Desert Landscape: The Stimson Formation as Exposed in the Murray Buttes, Gale Crater, Mars

“…As the superimposed dunes migrated across the lee slope of the draa, cross‐sets generated by the superimposed bedform were preserved in the lower section of the draa lee‐slope, as a coset of cross‐bedding (Figure 15 (Allen, 1968; Brookfield, 1977; Rubin & Hunter, 1983). This arrangement of bedforms that generate compound cross‐strata—a compound dune—is a commonly observed landform on both Earth (Breed, Fryberger, et al., 1979; Breed & Grow, 1979; Ford et al., 2010; Havholm & Kocurek, 1988; Lancaster, 1982; Sweet et al., 1988) and Mars (Breed, Grolier, & McCauley, 1979; Davis et al., 2020; Fenton, 2020). Superimposed bedforms arise as a result of near‐surface boundary layers caused by the presence of the draa‐scale bedforms (Rubin & Hunter, 1983; Rubin & McCulloch, 1980); these can be products of surface‐wave instability acting on a sufficiently large bed of sand (i.e., the stoss slope) (Elbelrhiti et al., 2005; Lü et al., 2017; Narteau et al., 2009).…”

The Aeolian Environment of the Landing Site for the ExoMars Rosalind Franklin Rover in Oxia Planum, Mars

“…We used well‐validated methods to co‐register and correlate images taken at different times (Table 1); this approach has previously been used to monitor many other active aeolian features on Mars and is well described by various authors (e.g., Ayoub et al., 2014; N. T. Bridges et al., 2012; Cardinale et al., 2016; Runyon et al., 2017; Silvestro et al., 2020, 2016). In summary, a stereo DTM was produced using the software packages ISIS and SocetSet, following standard procedures (J. M. Davis et al., 2020; Kirk, 2003; Kirk et al., 2008). This DTM was then used to co‐register and orthorectify overlapping HiRISE images taken at different times.…”

“…Repeat, high‐resolution orbital images and data from landers and rovers on the surface show that the sediment transport processes responsible for these aeolian features are currently active across much of the surface of Mars—a result of the interaction between surficial granular material and the thin Martian atmosphere. Encoded in these aeolian features is information about paleo and contemporary wind regimes, erosion rates, and sediment production, availability, transport, and flux (J. M. Davis et al., 2020). Quantifying and qualifying aeolian signals is therefore important for understanding the martian environment across a continuum of spatial and temporal scales and is also vital for operating a surface mission efficiently and safely.…”