HR: 16:45h
AN: P32C-04    [PDF]
TI: Numerical modeling of Martian rock glaciers: Implications for recent climate change
AU: * Colaprete, A
EM: tonyc@freeze.arc.nasa.gov
AF: NASA Ames, Moffett Field, MS 245-3, Mountain View, CA 94035 United States
AU: Haberle, R M
EM: Robert.M.Haberle@nasa.gov
AF: NASA Ames, Moffett Field, MS 245-3, Mountain View, CA 94035 United States
AB: Numerous geologic features suggest the presence of rock glaciers on the surface of Mars. These features include lobate debris aprons, concentric crater fill, and lineated valley fill. The lateral extent of these rock glaciers can range from 5 km to over 20 km. Previous work has demonstrated that these features could not have formed in current Martian conditions (1). It has long been speculated that changes in Mars' orbital properties, namely its obliquity, eccentricity, and argument of perihelion, can result in dramatic changes to climate (2). Recent climate model studies have shown that at periods of increased obliquity north polar water ice is mobilized southward and deposit at low and mid latitudes (3). Mid latitude accumulation of ice would provide the necessary conditions for rock glaciers to form. A time-marching model is used to demonstrate the ability of ice and ice-rock mixtures to flow under a variety of possible Martian conditions. Input to this model is constrained by observations and results from the NASA Ames Mars GCM. Modeled glacier heights and lengths are compared to observed rock glacier morphologies. (1) Colaprete and Jakosky, [1998] (2) Jakosky et al., [1993, 1995] (3) Mischna et al. [2003]
DE: 5400 PLANETOLOGY: SOLID SURFACE PLANETS
DE: 5416 Glaciation
DE: 5445 Meteorology (3346)
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting