HR: 1340h
AN: MR13A-0071    [Abstracts]
TI: An Approach to Planetary Core Formation: A First Transient Numerical Model
AU: * Ziethe, R
EM: ziethe@phim.unibe.ch
AF: Insitute of Geophysics, ETH Zuerich, ETHZ, HPP P4, Hoenggerberg, Zuerich, 8093 Switzerland
AU: Benz, W
EM: benz@phim.unibe.ch
AF: Institute of Physics, University of Berne, Sidlerstr. 5, Bern, 3012 Switzerland
AU: Giardini, D
EM: giardini@sed.ethz.ch
AF: Insitute of Geophysics, ETH Zuerich, ETHZ, HPP P4, Hoenggerberg, Zuerich, 8093 Switzerland
AU: Tackley, P J
EM: ptackley@ucla.edu
AF: Insitute of Geophysics, ETH Zuerich, ETHZ, HPP P4, Hoenggerberg, Zuerich, 8093 Switzerland
AB: The formation of an iron core in a terrestrial planets is still not well understood. Nevertheless there are some preferred models for the differentiation of the iron and silicate phase. One of them is the sinking of kilometer--sized iron bodies (diapirs) though the solid and relatively cold mantle of a proto--planet. These diapirs could originate from the iron layer at the bottom of a magma ocean by a Rayleigh--Taylor instability. They can also be provided as cores of pre--differentiated planetesimals. The numerical model simulates the the sinking of up to 100km large iron diapirs through the silicate mantle. The first approach was done using a stationary model with a single diapir on a fixed mesh. Although the model was simple and we made some rough assumptions, we could already explain some major features of core formation by sinking hot iron diapirs, e.g. the core superheat or the fast core formation time. Nevertheless there are many possibilities to improve the model. The first step is achieved by using a transient version of the underlying software package (FEATFLOW). It is now possible to simulate several objects falling simultaneously in a spherical geometry. We can study the diapir movement and observe how they influence each other. Here we discuss the method and present some early results that were obtained with the extended numerical simulation package.
DE: 0545 Modeling (4255)
DE: 1038 Mantle processes (3621)
DE: 5430 Interiors (8147)
DE: 8125 Evolution of the Earth (0325)
DE: 8147 Planetary interiors (5430, 5724, 6024)
SC: Mineral and Rock Physics [MR]
MN: Fall Meeting 2005