HR: 0800h
AN: U41B-0415    [Abstracts]
TI: The relationship between mantle models and core-mantle boundary topography
AU: * Lassak, T M
EM: Teresa.Lassak@asu.edu
AF: Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287-1404, United States
AU: McNamara, A K
EM: allen.mcnamara@asu.edu
AF: Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287-1404, United States
AU: Zhong, S
EM: szhong@anquetil.colorado.edu
AF: University of Colorado, Department of Physics, Boulder, CO 80309-0390, United States
AB: We numerically model convection (thermochemical and isochemical) and core-mantle boundary (CMB) topography, in an effort to determine its usefulness in constraining mantle models. From our study, the most negative CMB topography for an isochemical mantle strongly correlates with regions of subduction, whereas topography beneath regions of subduction in a thermochemical mantle is not exclusively negative. In fact, inclusion of thermochemical piles leads to an overall reduction in magnitude of CMB topography, relative to isochemical models, and flat to slightly positive topography beneath thermochemical piles. Topography maps yielded from numerous investigations do not exhibit the strong relationship between topography and subduction seen in the isochemical mantle model. This, in conjunction with geochemical data, may further indicate that Earth's mantle is likely a thermochemical mantle and pushes us to further investigate the nature of the seismically observed anomalies beneath the central Pacific and Africa. Moving beyond our previous work, we investigate these mantle models and the resulting CMB topography in three-dimensions and compare them to existing topography maps for Earth's CMB.
DE: 7208 Mantle (1212, 1213, 8124)
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8162 Rheology: mantle (8033)
SC: Union [U]
MN: 2007 Fall Meeting