HR: 0830h
AN: T41C-0242    [PDF]
TI: Interaction of the Iceland Plume and the Mid-Atlantic Ridge: the Effect of Detailed Ridge Geometry and Mantle Flow
AU: * Mihalffy, P
EM: mihalffy@geophysik.uni-frankfurt.de
AF: Institute of Meteorology and Geophysics, Goethe University, Feldbergstrasse 47, Frankfurt, 60323 Germany
AU: Schmeling, H
EM: schmeling@geophysik.uni-frankfurt.de
AF: Institute of Meteorology and Geophysics, Goethe University, Feldbergstrasse 47, Frankfurt, 60323 Germany
AU: Steinberger, B
EM: bernhard@jamstec.go.jp
AF: Institute for Frontier Research on Earth Evolution Japan Marine Science and Technology Center, 2-15 Natsushima-cho, Yokosuka-shi, 237-0061 Japan
AB: The interaction of the Iceland plume with a global mantle flow field is investigated in 3D numerical models. The approach consists of two steps. First the large-scale mantle flow field is calculated in a global model, in the whole mantle. This global and robust flow field serves as a background flow in the regional model, in which the interaction of the mid-Atlantic ridge and the Iceland plume is calculated. A time-dependent model of the large-scale mantle flow field was obtained by using paleogeometries of the Atlantic and Eurasian plates reconstructed from magnetic anomalies and by advecting density anomalies backward in time. The motion of the plume source on the bottom of the model box is calculated according to the distortion of an initally vertical plume conduit in the large-scale mantle flow field. In the regional model the changing large-scale flow field and the moving plume source are introduced as time dependent boundary conditions. In this way, the interaction of the Iceland plume and the mid-Atlantic ridge is investigated in a 3D model containing detailed ridge geomtery. Results with time independent boundary conditions show that the large-scale mantle flow field controls the development of the plume. In the regional model the plume is tilted to the north in the upper mantle, which is also shown by seismology. However, the northward channeling of the plume material in the model does not explain the geochemical anomalies, which show an increased plume influence south of Iceland. Simulations with time dependent boundary conditions (time dependent ridge geometry and plume source position) modify this channelling of plume material and give a more precise view of plume-ridge interaction.
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 3210 Modeling
DE: 8121 Dynamics, convection currents and mantle plumes
DE: 8157 Plate motions--past (3040)
SC: Tectonophysics [T]
MN: 2003 Fall Meeting