HR: 1340h
AN: P33A-1014    [Abstracts]
TI: Planetary Interiors: Parametric Modeling of Global Geophysical Properties
AU: * Montgomery, W
EM: wren@eps.berkeley.edu
AF: Department of Earth & Planetary Science, 307 McCone Hall \#4767 UC Berkeley, Berkeley, CA 94720-4767 United States
AU: Jeanloz, R
EM: jeanloz@berkeley.edu
AF: Department of Earth & Planetary Science, 307 McCone Hall \#4767 UC Berkeley, Berkeley, CA 94720-4767 United States
AB: Taking into account a realistic form of equation of state, we parameterize the degree to which bulk geophysical properties of planets are sensitive to gravitational self-compression. For example, the normalized moment of mass of a uniform-composition planet is C/Ma$^{2}$ = 0.40 only in the limit of zero planetary size or incompressible material, and decreases toward 0.32 for finite compressibility as the planetary radius increases toward a = 10$^{4}$ km (M is planetary mass). Central density correspondingly increases from $\rho_{0}$, the surface density, toward 10 * $\rho_{0}$. Our calculations, based on the Eulerian finite-strain equation of state, make it possible to distinguish the effects of self-compression from the effects of non-uniformity (due either to changes in bulk composition or in phase with depth) as these influence planetary mass and moment of inertia relative to size. As observations of extra-solar planets can provide estimates of their mass and diameter (hence mean density), our formulation can account for the effects of compression in modeling the internal constitution and evolution of these objects. The effects of compression are especially important for giant and super-giant planets, such as the majority that have been observed to date.
DE: 5430 Interiors (8147)
DE: 6207 Comparative planetology
DE: 3919 Equations of state
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting