Publication

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. Several models exist describing the interaction of a plume with the lithosphere. However, up until now, seismic imaging techniques did not have sufficient resolution to distinguish between the models. We applied the S receiver function technique (see supplement) to data of three permanent seismic broadband stations on the Hawaiian islands to map the thickness of the lithosphere in unprecedented 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 here it thins gradually along the island chain to about 50 60 km below Kauai. The lithosphere shows normal thickness beyond about 150 km NE and SW 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 to conditions existing 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 halved within that time.

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Li, X. Q.; Kind, R.; Yuan, X.; Wölbern, I.; Hanka, W. (2004): Rejuvenation of the lithophere by the Hawaiian plume. 1st General Assembly European Geosciences Union (Nice, France 2004).