HR: 08:30h
AN: MR21A-03 INVITED     [Abstracts]
TI: MgSiO$_3$ post-perovskite at D" conditions
AU: * Tsuchiya, T
EM: takut@cems.umn.edu
AF: Chemical Engineering and Materials Science, Minnesota Supercomputing Institute for Digital Technology and Advanced Computation, University of Minnesota, 421 Washington Av SE, Minneapolis, MN 55455 United States
AU: Tsuchiya, J
EM: junt@cems.umn.edu
AF: Chemical Engineering and Materials Science, Minnesota Supercomputing Institute for Digital Technology and Advanced Computation, University of Minnesota, 421 Washington Av SE, Minneapolis, MN 55455 United States
AU: Umemoto, K
EM: umemoto@cems.umn.edu
AF: Chemical Engineering and Materials Science, Minnesota Supercomputing Institute for Digital Technology and Advanced Computation, University of Minnesota, 421 Washington Av SE, Minneapolis, MN 55455 United States
AU: Wentzcovitch, R M
EM: wentzcov@cems.umn.edu
AF: Chemical Engineering and Materials Science, Minnesota Supercomputing Institute for Digital Technology and Advanced Computation, University of Minnesota, 421 Washington Av SE, Minneapolis, MN 55455 United States
AB: The thermoelastic properties of the new polymorph of MgSiO$_3$ with the CaIrO$_3$ structure and more stable than the Pbnm-perovskite phase at conditions close to those expected in the D" region has been investigated by first-principles computations and contrasted with those of the perovskite phase. Although we investigate only single and pure phases, the elasticity of aggregates containing predominantly these phases is expected to differ similarly, although in smaller magnitude. We therefore predict the major trends in seismic properties expected to occur in the presence of such phase change, such as velocity discontinuities, ratios of velocities and density anomalies, and anisotropy in aggregates with preferred orientation. Consequences of this model mineralogy for the D" region will be discussed. J. Tsuchiya and T. Tsuchiya thank JSPS for research fellowships. Research supported by NSF/EAR 0135533 (COMPRES), 0230319.
DE: 3600 MINERALOGY AND PETROLOGY (replaces
DE: 3900 MINERAL PHYSICS
DE: 3909 Elasticity and anelasticity
DE: 3924 High-pressure behavior
DE: 3939 Physical thermodynamics
SC: Mineral and Rock Physics [MR]
MN: 2004 AGU Fall Meeting