HR: 1330h
AN: V32A-0988    [PDF]
TI: Rejuvenation of the Lithosphere by the Hawaiian Plume
AU: * Kind, R
EM: kind@gfz-potsdam.de
AF: GFZ Potsdam, Telegrafenberg, 14473, Potsdam Germany
AU: Li, X
AF: GFZ Potsdam, Telegrafenberg, 14473, Potsdam Germany
AU: Yuan, X
AF: GFZ Potsdam, Telegrafenberg, 14473, Potsdam Germany
AU: Woelbern, I
AF: GFZ Potsdam, Telegrafenberg, 14473, Potsdam Germany
AU: Hanka, W
AF: GFZ Potsdam, Telegrafenberg, 14473, Potsdam Germany
AB: Thickness of oceanic lithosphere increases with distance from the ocean ridge due to cooling. If the lithosphere overrides a mantle plume, it will be modified. There exist several models describing the interaction of a plume with the lithosphere. However, existing seismic imaging techniques did not have sufficient resolution to decide for one of the models. We applied the S receiver function technique to data of three permanent seismic broadband stations on the Hawaiian islands to map the thickness of the lithosphere in so far unequaled detail. Under Big Island the lithosphere is 100-110 km thick, as expected for a 90-100 Myr old oceanic plate not modified by a plume. From there it is thinning gradually along the island chain to about 50-60 km below Kauai. The lithosphere retains its normal thickness in the region about 150 km to the north and to the south of the island chain, still well within the region of the topographic swell. Our data favour the rejuvenation model, in which the plume returns the lithosphere into conditions close to its origin at the mid ocean ridge. The maximum observed rejuvenation of the lithosphere at Kauai is delayed by about 3-4 Myr (the approximate age difference between Big Island and Kauai) and its thickness is nearly cut in half within that time.
DE: 7200 SEISMOLOGY
DE: 7218 Lithosphere and upper mantle
DE: 8121 Dynamics, convection currents and mantle plumes
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting