Meeting room "Glova", 4 floor, Integrated Research Building
Abstract
We examined the influences of the chemical heterogeneity in the mantle on the generation of plumes by numerical simulations of mantle convection with chemical heterogeneity and continental drift. In this study, we adopted a model of two-dimensional rectangular box geometry and periodic boundary condition. We placed a mobile lid as a model of drifting supercontinent whose viscosity is 103 times larger than that of the surrounding fluid. In addition, the mantle materials are assumed to be a mixture of two components with different density. We studied the influences of the chemical buoyancy on the generation of plumes by changing a density difference between high and low density components. From the results of calculations, we found that the chemically dense materials which form the LLSVP are denser by at least 0.5 percents than the surrounding mantle and account for about 10 percents of the entire mantle. In addition, from the variations of convective planform, we found that the large chemical pile, once it forms beneath the initial continental position, is almost stationary for more than several giga years. This suggests that the cyclic changes in convection patterns such as the "1-2-1 model" do not operate easily, considering the effect of chemical heterogeneity in the mantle.
For inquiry：Taku Tsuchiya TEL:（089）927-8198
E-mail takut@sci.ehime-u.ac.jp
