Geophysical Research Letters

Supporting Information for

Morphologic Diversity of Martian Ripples: Implications for Large-Ripple Formation

M.G.A. Lapotre1, R.C. Ewing2, C.M. Weitz3, K.W. Lewis4, M.P. Lamb5, B.L. Ehlmann5,6, and D.M. Rubin7.

1Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138.2Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843.3Planetary Science Institute, Tucson, AZ 85719-2395.4Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218.5Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125.6Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109.7Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064.

Contents of this file

Figure S1Figure S2Table S1Supplementary References

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Figure S1: (a) Global distribution of martian dune fields found within ± 65° on Mars Orbiter Laser Altimetry (MOLA) topography [Hayward et al., 2007]. The white arrow indicates the location of Gale crater. (b) Color HiRISE mosaic over the Bagnold Dunes, Gale crater. Curiosity’s traverse is shown in a white line. The inset shows Gale crater for context, with the white box indicating the approximate extent of panel (b). (c) Color HiRISE image (ESP_044172_1755, acquired 29 Dec. 2015, sol 1207) over Namib Dune showing Curiosity investigating the dune’s lee slope.

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Figure S2: (a) Longitudinal spurs [e.g., Swanson et al., 2018] on the lee side of tidal dunes, Loughor Estuary, South Wales (Photography by Trevor Elliott; Figure 49 of Rubin and Carter [2006]). The trowel is 28 cm long. (b) Longitudinal eolian ripples forming in the lee of vegetation on a sand bar in Grand Canyon, Arizona. (c) Longitudinal eolian ripples forming in the lee of a larger bedform stabilized by

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vegetation in Namib Desert, Namibia. In (b)-(c), dominant winds are roughly from right to left, and dashed lines bound the extent of longitudinal ripples.

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Table S1: Morphological and dynamical characteristics of martian eolian-ripple types as documented with the Curiosity rover at Gale crater.

Ripple type

Orientation

Wavelength

Crestline

geometry

Cross-sectional

shapeGrain size Activity

Impact ripples

transverse ~5-20 cm linear relatively

symmetricmonodisperse, generally fine

active[e.g., Baker et al., this issue]

Large ripples

transverse/

oblique~1-5 m

straight to highly sinuous

asymmetric, some with near-angle-

of-repose lee faces

monodisperse, generally fine

active[e.g., Silvestro et al., 2016]

longitudinal/

oblique~1-5 m linear symmetric monodisperse,

generally fineactive

[e.g., Silvestro et al., 2016]

Coarse-

grained

ripples*

transverse 5 cm-3 m linear asymmetric

bulk is monodisperse and fine, but crests are coarser, with grains

up to >1 mm [Weitz et al., this

issue]

non-active to active

[Weitz et al., this issue]

* Table reports for coarse-grained ripples observed in situ with Curiosity. Orbiter-based data suggest martian coarse-grained ripples might also form longitudinally, encompass a broader range of wavelengths (up to 10s of meters), adopt complex crestline geometries and varied cross-sectional shapes.

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Supplementary References

Baker, M., M. Lapotre, N. Bridges, M. Minitti, C. Newman, B. Ehlmann, A. Vasavada, K. Edgett, and K. Lewis (2018b), The Bagnold Dunes in southern summer: Active sediment transport on Mars observed by the Curiosity rover, Geophysical Research Letters.

Hayward, R. K., K. F. Mullins, L. K. Fenton, T. M. Hare, T. N. Titus, M. C. Bourke, A. Colaprete, and P. R. Christensen (2007), Mars global digital dune database and initial science results, Journal of Geophysical Research: Planets, 112(E11), doi: 10.1029/2007JE002943

Rubin, D., and C. Carter (2006), Bedforms and cross-bedding in animation, SEPM Society for Sedimentary Geology.

Silvestro, S., D. Vaz, H. Yizhaq, and F. Esposito (2016), Dune‐like dynamic of Martian Aeolian large ripples, Geophysical Research Letters, 43(16), 8384-8389, doi: 10.1002/2016GL070014.

Swanson, T., D. Mohrig, G. Kocurek, M. Perillo, and J. Venditti (2018), Bedform spurs: a result of a trailing helical vortex wake, Sedimentology, 65(1), 191-208, doi: 10.1111/sed.12383.

Weitz, C., R. Sullivan, M. Lapotre, S. Rowland, J. Grant, M. Baker, and R. Yingst (2018), Sand grain sizes and shapes in eolian bedforms at Gale crater, Mars, Geophysical Research Letters.

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