Wind-driven particle mobility on Mars: Insights from MER observations at "El Dorado" and surroundings at Gusev Crater

Journal of Geophysical Research E: Planets
By: , and 



The ripple field known as “El Dorado” was a unique stop on Spirit's traverse where dust‐raising, active mafic sand ripples and larger inactive coarse‐grained ripples interact, illuminating several long‐standing issues of Martian dust mobility, sand mobility, and the origin of transverse aeolian ridges. Strong regional wind events endured by Spirit caused perceptible migration of ripple crests in deposits SSE of El Dorado, erasure of tracks in sandy areas, and changes to dust mantling the site. Localized thermal vortices swept across El Dorado, leaving paths of reduced dust but without perceptibly damaging nearly cohesionless sandy ripple crests. From orbit, winds responsible for frequently raising clay‐sized dust into the atmosphere do not seem to significantly affect dunes composed of (more easily entrained) sand‐sized particles, a long‐standing paradox. This disparity between dust mobilization and sand mobilization on Mars is due largely to two factors: (1) dust occurs on the surface as fragile, low‐density, sand‐sized aggregates that are easily entrained and disrupted, compared with clay‐sized air fall particles; and (2) induration of regolith is pervasive. Light‐toned bed forms investigated at Gusev are coarse‐grained ripples, an interpretation we propose for many of the smallest linear, light‐toned bed forms of uncertain origin seen in high‐resolution orbital images across Mars. On Earth, wind can organize bimodal or poorly sorted loose sediment into coarse‐grained ripples. Coarse‐grained ripples could be relatively common on Mars because development of durable, well‐sorted sediments analogous to terrestrial aeolian quartz sand deposits is restricted by the lack of free quartz and limited hydraulic sediment processing.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Wind-driven particle mobility on Mars: Insights from MER observations at "El Dorado" and surroundings at Gusev Crater
Series title Journal of Geophysical Research E: Planets
DOI 10.1029/2008JE003101
Volume 115
Issue E6
Year Published 2008
Language English
Publisher American Geophysical Union
Contributing office(s) Astrogeology Science Center
Description 70 p.
Other Geospatial Mars
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