Large wind ripples on Mars: A record of atmospheric evolution

M G A Lapotre; R C Ewing; M P Lamb; W W Fischer; J P Grotzinger; D M Rubin; K W Lewis; M J Ballard; M Day; S Gupta; S G Banham; N T Bridges; D J Des Marais; A A Fraeman; J A Grant; K E Herkenhoff; D W Ming; M A Mischna; M S Rice; D Y Sumner; A R Vasavada; R A Yingst

doi:10.1126/science.aaf3206

Large wind ripples on Mars: A record of atmospheric evolution

Science. 2016 Jul 1;353(6294):55-8. doi: 10.1126/science.aaf3206.

Authors

M G A Lapotre¹, R C Ewing², M P Lamb³, W W Fischer³, J P Grotzinger³, D M Rubin⁴, K W Lewis⁵, M J Ballard², M Day⁶, S Gupta⁷, S G Banham⁷, N T Bridges⁸, D J Des Marais⁹, A A Fraeman¹⁰, J A Grant¹¹, K E Herkenhoff¹², D W Ming¹³, M A Mischna¹⁴, M S Rice¹⁵, D Y Sumner¹⁶, A R Vasavada¹⁴, R A Yingst¹⁷

Affiliations

¹ Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA 91125, USA. mlapotre@caltech.edu.
² Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA.
³ Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA 91125, USA.
⁴ Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA.
⁵ Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
⁶ Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78712, USA.
⁷ Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, UK.
⁸ Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA.
⁹ NASA Ames Research Center, Moffett Field, CA 94035, USA.
¹⁰ Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA 91125, USA. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
¹¹ National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA.
¹² Astrogeology Science Center, U.S. Geological Survey, Flagstaff, AZ 86001-1698, USA.
¹³ NASA Johnson Space Center, Houston, TX 77058, USA.
¹⁴ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
¹⁵ Geology Department, Western Washington University, Bellingham, WA 98225-9080, USA.
¹⁶ Department of Earth and Planetary Sciences, University of California, Davis, CA 95616, USA.
¹⁷ Planetary Science Institute, Tucson, AZ 85719, USA.

PMID: 27365444
DOI: 10.1126/science.aaf3206

Abstract

Wind blowing over sand on Earth produces decimeter-wavelength ripples and hundred-meter- to kilometer-wavelength dunes: bedforms of two distinct size modes. Observations from the Mars Science Laboratory Curiosity rover and the Mars Reconnaissance Orbiter reveal that Mars hosts a third stable wind-driven bedform, with meter-scale wavelengths. These bedforms are spatially uniform in size and typically have asymmetric profiles with angle-of-repose lee slopes and sinuous crest lines, making them unlike terrestrial wind ripples. Rather, these structures resemble fluid-drag ripples, which on Earth include water-worked current ripples, but on Mars instead form by wind because of the higher kinematic viscosity of the low-density atmosphere. A reevaluation of the wind-deposited strata in the Burns formation (about 3.7 billion years old or younger) identifies potential wind-drag ripple stratification formed under a thin atmosphere.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.