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trajectories and energy transfer of saltating particles onto rock surfaces : application to abrasion and ventifact formation on earth and marsThe interaction between saltating sand grains and rock surfaces is assessed to gauge relative abrasion potential as a function of rock shape, wind speed, grain size, and planetary environment. Many kinetic energy height profiles for impacts exhibit a distinctive increase, or kink, a few centimeters above the surface, consistent with previous field, wind tunnel, and theoretical investigations. The height of the kink observed in natural and wind tunnel settings is greater than predictions by a factor of 2 or more, probably because of enhanced bouncing off hard ground surfaces. Rebounded grains increase the effective flux and relative kinetic energy for intermediate slope angles. Whether abrasion occurs, as opposed to simple grain impact with little or no mass lost from the rock, depends on whether the grain kinetic energy (EG) exceeds a critical value (EC), as well as the flux of grains with energies above EC. The magnitude of abrasion and the shape change of the rock over time depends on this flux and the value of EG > EC. Considering the potential range of particle sizes and wind speeds, the predicted kinetic energies of saltating sand hitting rocks overlap on Earth and Mars. However, when limited to the most likely grain sizes and threshold conditions, our results agree with previous work and show that kinetic energies are about an order of magnitude greater on Mars.
Document ID
20060044082
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Bridges, Nathan T.
Phoreman, James
White, Bruce R.
Greeley, Ronald
Eddlemon, Eric E.
Wilson, Gregory R.
Meyer, Christine J.
Date Acquired
August 23, 2013
Publication Date
December 7, 2005
Publication Information
Publication: Journal of Geophysical Research
Volume: 111
Subject Category
Lunar and Planetary Science and Exploration
Distribution Limits
Public
Copyright
Other
Keywords
planet sufraces
Mars surface