Origin and Deformation of the Ontong Java Plateau

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The Ontong Java Plateau (OJP) covers 2 million km2 of seafloor, made up of 100 million km3 lavas that erupted rapidly ~120 Ma. This event represented a major heat and mass transfer from the Earth's deep interior to the surface. The cause of this magmatic event and the associated deformation of the plate on which this large load was emplaced are unclear. Recent work by these scientists has identified seismic structure in the mantle beneath the OJP that can only be explained by rock composition that would correspond to recycled oceanic crust. If true, this would suggest that subducted oceanic plates do not complete assimilate in the deep Earth. At least portions can survive the high temperatures and pressures and be caught up in global mantle circulation. Validating the presence of a mechanically strong mantle root beneath the OJP with quantitative estimates of its physical and chemical characteristics is expected to further understanding of the evolution of the oceanic lithosphere and the formation and survival of continental cratonic keels.A team of scientists from Japan, UK, and US are deploying ocean-bottom seismometers, electromagnetometers, and land based seismic stations on and around the Ontong Java between 2014-2016. This project supports US scientists and students to participate in onshore seismic data collection and analysis of the full amphibious dataset. All the seismic data for the combined projects will be shared among all the team and analyzed in collaboration. The US scientists will conduct advanced seismic analysis using 3-D full-wave tomography, and characterizations of anisotropy and attenuation. The new results would achieve 1° resolution, much improved over the current ~5° resolution that has led to contrasting interpretations of the distribution of low velocity within the OJP root. Teaching modules will be created and made available at Carleton College's On the Cutting Edge Geoscience site. Aspects of the data, analysis techniquest, and interpretation will be incorporated in undergraduate and graduate courses.