DPS 2001 meeting, November 2001
Session 19. Mars Atmosphere Posters
Displayed, 9:00am Tuesday - 3:00pm Saturday, Highlighted, Wednesday, November 28, 2001, 10:30am-12:30pm, French Market Exhibit Hall

[Previous] | [Session 19] | [Next]

[19.05] Characterization of Sand Dunes in Proctor Crater on Mars by Application of a Mesoscale Model (the Mars MM5) and by Development of a Graphical Information System (GIS)

L. K. Fenton, M. I. Richardson (Caltech), J. L. Bandfield (Goddard Space Flight Center), A. W. Ward (USGS), A. L. Albee (Caltech), A. D. Toigo (Cornell U.)

Aeolian action is most likely the dominant geologic process currently acting on the surface of Mars. Data recently acquired by the Mars Global Surveyor have provided an unprecedented opportunity to study in detail the surface features produced by aeolian activity in the area of the southern highlands west of the Hellas Basin. All available data sets have been incorporated into a Graphical Information System (GIS) in order to correlate aeolian features with data products from the Thermal Emission Spectrometer (e.g., albedo, thermal inertia, and composition) and from the Mars Orbiter Laser Altimeter (e.g., surface roughness and elevation). In addition, a mesoscale model (the Mars MM5) has been applied over the study area to determine sand transport capacity and dominant wind directions.

We present results from Proctor Crater, a large (~150 km diameter), prominent, and well-studied crater of the southern highlands of Mars. In the eastern portion of Proctor Crater is a dunefield that spans 60 x 35 km. It consists of what has been traditionally thought of as large (~1 km spacing), dark transverse dune ridges.

Analysis of the GIS has led to numerous conclusions regarding the dunes of Proctor Crater. Surficial mapping of dune crests has led to the hypothesis that the dunes are not transverse (i.e., perpendicular to the dominant dune-forming wind) but that instead they are longitudinal (i.e., parallel to the resultant of multiple dune-forming winds). Mesoscale modeling supports the existence of a complex wind regime that affects the shape of the dunes and determines the state of activity of sand saltation. Close inspection of high resolution images (from the Narrow Angle camera on the Mars Orbiter Camera) reveals that the large dark dunes are surrounded by smaller (~30 m spacing), higher albedo duneforms with which they share a complex interaction. Compositional analysis of Proctor Crater has determined that the dark dunes are largely basaltic, more so than the basaltic highlands in which they are located. Calculations of thermal properties have led to estimates of average particle sizes and albedo values for both the dark and bright dunes. These results demonstrate the effectiveness of GIS analysis and the importance of high resolution atmospheric modeling. This work has been supported by the Mars Data Analysis Program.

The author(s) of this abstract have provided an email address for comments about the abstract: lori@gps.caltech.edu

[Previous] | [Session 19] | [Next]