Collaborative Research: NSFGEO-NERC: Magnetotelluric imaging and geodynamical/geochemical investigations of plume-ridge interaction in the Galapagos

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How magma flows from the Earth’s mantle to the surface is poorly understood. Does it flow slowly through the mantle, or quickly through melt-rich channels? Answering this question will help understand where seafloor volcanoes form and how frequently they erupt. The project will acquire new geophysical and geological data in the Galapagos islands. This region has volcanism all the way from the main archipelago to the mid-ocean ridge a few hundred km away. The investigators will combine the new data with theoretical modeling to test different models for magma flow. The results will be important for other locations such as Reunion Island, Azores Islands, and Easter Island as well as global subduction zones. Broader impacts include support and training of a graduate student and postdoctoral scholar, opportunities for early career scientists to participate in the research cruise, collaboration with the Charles Darwin Foundation in Galapagos, and outreach to the public and K-12 students. This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries.The proposed works aims to significantly improve the understanding of melt transport in the asthenosphere, and melt localization processes, through an integrated multidisciplinary study. As a case study, the project will focus upon mantle plume/mid-ocean ridge interaction in the Galapagos which is exemplified by the enigmatic Wolf-Darwin Lineament. The proposed work includes three key components: (1) New marine resistivity imaging using magnetotelluric data sets for imaging melt distribution (with deployment of 90 ocean bottom broadband MT sites); (2) Geochemical analysis (major and trace elements, volatile content, Sr, Nd, Pb and Fe isotopes) of existing and new dredge samples along the northern Galapagos lineaments and Western Galapagos Spreading Center; and (3) Geodynamical modeling of two-phase melt channelization to constrain the physical viability of melt localization. These results will be integrated to generate a new global model for plume-ridge interaction and asthenospheric melt transport in general.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.