SEMINAR - Gabi Laske

The Hawaiian PLUME Experiment and its Initial Data Assessment

Gabi Laske
Institute of Geophysics and Planetary Physics
Scripps Institute of Oceanography
University of California, San Diego

March 19th, 2008

Hawaii has long been viewed as the textbook example for a plume-fed hotspot. Yet, the plume model has been contested because the collected seismic data to support or disprove it have so far been inconclusive. Compelling constraints on even the most basic features such as the plume conduit and its head have been elusive. One major problem that seismology has faced has been its complete reliance on land-based stations.

During the Jan. 2005 – May 2007 Hawaiian PLUME experiment we occupied nearly 70 sites with broad-band ocean bottom seismometers (OBSs). We collected continuous time series at a 1000 km-wide array that was augmented by 10 dedicated sites on the Hawaiian islands. The seismic data will facilitate the construction of surface wave and body wave tomographic images of never-before obtained coverage and a depth-extent that reaches well into the lower mantle. The data will also be used to constrain the topography of mantle discontinuities through receiver functions and anisotropy through shear-wave splitting. The data analysis has just begun and in my talk, I will present our first images obtain from surface waves.