Water induced sediment levitation enhances downslope transport on Mars

作者：Raack Jan; Conway Susan J; Herny Clemence; Balme Matthew R; Carpy Sabrina; Patel Manish R

来源：Nature Communications, 2017, 8(1): 1151.

DOI：10.1038/s41467-017-01213-z

On Mars, locally warm surface temperatures (similar to 293 K) occur, leading to the possibility of (transient) liquid water on the surface. However, water exposed to the martian atmosphere will boil, and the sediment transport capacity of such unstable water is not well understood. Here, we present laboratory studies of a newly recognized transport mechanism: "levitation" of saturated sediment bodies on a cushion of vapor released by boiling. Sediment transport where this mechanism is active is about nine times greater than without this effect, reducing the amount of water required to transport comparable sediment volumes by nearly an order of magnitude. Our calculations show that the effect of levitation could persist up to similar to 48 times longer under reduced martian gravity. Sediment levitation must therefore be considered when evaluating the formation of recent and present-day martian mass wasting features, as much less water may be required to form such features than previously thought.

• 出版日期2017-10-27