HR: 0800h
AN: T51B-0544    [Abstracts]
TI: Earth Sphericity Effects on Subduction Morphology
AU: * Morra, G
EM: gabriele.morra@erdw.ethz,ch
AF: Geology - Roma Tre University, Largo Murialdo, Roma, Roma, 00100,
AU: * Morra, G
EM: gabriele.morra@erdw.ethz,ch
AF: Geophysics Department - ETH Zuerich, ETH Hoenggerbger, Zuerich, 8093,
AU: Chatelain, P
EM: pchatela@inf.ethz.ch
AF: Computational Sciences - ETH Zuerich, ETH Zentrum, Zuerich, 8093,
AU: Tackley, P
EM: ptackley@ethz.ch
AF: Geophysics Department - ETH Zuerich, ETH Hoenggerbger, Zuerich, 8093,
AU: Koumoutsakos, P
EM: petros@inf.ethz.ch
AF: Computational Sciences - ETH Zuerich, ETH Zentrum, Zuerich, 8093,
AB: We present here the first application in Geodynamics of a Multipole accelerated Boundary Element Method (FMM- BEM) for Stokes Flow. The approach offers the advantage of a reduced number of computational elements and linear scaling with the problem size. We show that this numerical mehod can be fruitfully applied to the simulation of several geodynamic systems at the planetary scale in spheical coordinates and we suggest a general appraoch for modeling combined mantle convection and plate tectonics. The potentialities of the approach are shown investigating the effect played by Earth sphericity on the subduction of a very wide oceanic lithosphere , comparing the morphology of the subducted lithosphere in a spherical and in flat setting. The results show a striking difference between the two models: while the slab on a "flat Earth" shows slight undulation, the same subducting plate on a spherical Earth-like setting presents a distinct folding below the trench far from the edges, with wavelength of (1000km-2000km) as Pacific trenches.
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8125 Evolution of the Earth (0325)
DE: 8138 Lithospheric flexure
DE: 8150 Plate boundary: general (3040)
DE: 8170 Subduction zone processes (1031, 3060, 3613, 8413)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting