HR: 17:05h
AN: V54A-05 INVITED     [Abstracts]
TI: Rejuvenation of the Pacific lithosphere by the Hawaiian plume
AU: * Kind, R
EM: kind@gfz-potsdam.de
AF: GFZ Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Li, X
EM: li@gfz-potsdam.de
AF: GFZ Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Yuan, X
EM: yuan@gfz-potsdam.de
AF: GFZ Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Woelbern, I
EM: woelbern@gfz-potsdam.de
AF: GFZ Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Kumar, P
EM: prakash@gfz-potsdam.de
AF: GFZ Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AB: S-to-P converted seismic waves have in recent times proven to be able to locate the lithosphere-asthenosphere boundary (LAB) with an accuracy so far only known for the crust-mantle boundary. The data used come from permanent and mobile broadband stations on the Hawaiian islands. We have located the LAB beneath the active volcanic Big Island at 100 km depth and shallowing towards Kauai to 60 km depth in an about 200 km wide stripe. Our interpretation is that the Pacific lithosphere is rejuvenated during its passage over the plume, and this rejuvenation occurs delayed. We also find only below the Big Island at 140 km depth a zone of partial melting. The seismic discontinuity at 660 km depth is elevated (indicating surplus heat) in the south west of the Big Island, and not in the continuation of the island chain in the south east. This indicates that the plume is inclined and has its origin in the lower mantle. Finally we compare the Hawaiian results with lithospheric structure at the Iceland plume and its possible trace.
DE: 7208 Mantle (1212, 1213, 8124)
DE: 7218 Lithosphere (1236)
DE: 8121 Dynamics: convection currents, and mantle plumes
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005