HR: 16:00h
AN: P34A-01 INVITED     [Abstracts]
TI: Inferring Martian Surface Properties from Impact Crater Morphologies
AU: * Stewart, S T
EM: sstewart@eps.harvard.edu
AF: Harvard University, Department of Earth and Planetary Sciences, 20 Oxford St., Cambridge, MA 02138 United States
AB: The morphologies of Martian impact craters and ejecta reflect the dynamic strength, layered structure, and composition of the target materials. Using the Mars Orbiter Laser Altimeter data, significant differences in the geometrical properties of impact craters are resolved between lowland (Utopia Planitia and Isidis Planitia) and highland (Lunae Planum and Solis Planum) plains. Simple craters are deeper and rim uplifts are higher in the lowlands. The resulting cavity volume differences indicate that the lowland materials are a factor of two weaker than the highlands. Numerical simulations show that specific geometric markers, such as rim uplift height and cavity volumes, are sensitive to the abundance of ground ice, surface strength, and layered structures. I will present comparisons between the geometric observations and numerical simulations to constrain the properties of the surface materials in highland and lowland plains.
DE: 5410 Composition
DE: 5420 Impact phenomena (includes cratering)
DE: 5470 Surface materials and properties
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting