The rate of granule ripple movement on Earth and Mars

نویسندگان

  • James R. Zimbelman
  • Irwin
  • Steven H. Williams
  • Fred Bunch
  • Andrew Valdez
  • Scott Stevens
چکیده

The rate of movement for 3and 10-cm-high granule ripples was documented in September of 2006 at Great Sand Dunes National Park and Preserve during a particularly strong wind event. Impact creep induced by saltating sand caused 24 granules min 1 to cross each cm of crest length during wind that averaged 9 m s 1 (at a height well above 1 m), which is substantially larger than the threshold for saltation of sand. Extension of this documented granule movement rate to Mars suggests that a 25-cm-high granule ripple should require from hundreds to thousands of Earth-years to move 1 cm under present atmospheric conditions. Published by Elsevier Inc.

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تاریخ انتشار 2009